.... ========================================================================= From: Nicholas McKinney Subject: [JN] Re: Date: Thu, 15 Apr 1999 12:50:23 -0400 Source: Sound Digest Archive v02.n125 At 04:07 PM 4/15/99 +0100, John Hancock wrote: > > > >Nicholas McKinney wrote: > >>John, more woofer speed is higher frequency, don't you mean more >amplitude? > >My definition of speed is velocity: the first derivative of position. Is >there another definition?--no incredulity intended, I suspect that there >might be a subjective hi-fi use of the word speed that I am unfamiliar >with. You can either change the speed of the movement (faster increases frequency, smaller period, same amplitude) or change the amplitude (changes SPL, same period, same frequency) The position of the woofer with the increased amplitude is increased from fore to aft, is this what you are talking about? >I don't question that at all for DC motor systems that convert current into >force. I'm talking about a positional system, though, where all of this is >irrelevent. Hmmm, I would imagine that unless you can make a pure monopole system, you will still have the issue of the rear wave that is 180 degree out of phase from the front wave. If these 2 waveforms are allowed to meet without change to one, the net effect is a cancelation of acoustic power, even though the electrical input was constant. Basically, you need to either stick the driver in a box to "seal" off the rear wave, or use the listening room as the box (woofer in the wall leading to the outdoors is an extreme example) Both of these can be modeling using TS parameters. Nick ========================================================================= From: Rich Barrett Subject: Re: [JN] Date: Sun, 15 Aug 1999 21:51:26 -0400 Source: Sound Digest Archive v02.n247 Help, I mentioned this list to a gentleman today and he was very interested in getting on, but I can't seem to find a link or the correct address to get him started. Can anyone help me to help him? TIA Rich Barrett rdbear@earthlink.net ========================================================================= From: Thomas Danley Subject: [JN] Re: Date: Thu, 09 Dec 1999 14:20:50 -0500 Source: Sound Digest Archive v02.n359 John Hancock wrote: > Aaron wrote: > > >I wanted to reread the discussion we had a couple of months ago regarding > >a positional subwoofer system driven by a stepper motor and controller. > >I've tried to find it in my archives, etc. but haven't been able to. Did > >anyone save this or does anyone know which digests they were? > > Aaron, > > I think you are refering to my hairbrained scheme, which I gave up on after > Tom Danley pointed out that I had done my math wrong. At the time, I was > thinking of using a stepper motor that had something like 16 bit resolution > per turn and about a 3000 rpm rating (I had erroneously done the math using > 3000 rotations per second, argghh). That's not enough resolution to get > very much bandwidth. However, since then I received a catalog from Pacific > Scientific and they have a brushless servo motor/feedback system that can > attain 24 bit resolution per turn and 6000 rpm. This makes the scheme > possible, but also a lot more expensive. The advantage of the steppers is > they are cheap. Let me know if you are crazy enough to pursue this, > > John Crazy idea? no no and I hope I didn't quash your sense of curiosity. Like they say (or at least they should) "Many of the biggest discoveries were made by people that didn't know what they had done was impossible". This certainly was true for me making the first servodrive, in fact if you asked anyone in audio at the time "can a rotary motor accurately follow a musical signal?" the answer was certainly no, its unimaginable.. You might consider using an "open loop" low inertia DC servomotor as well, they can be driven with a normal audio signal and if the DCR is ok, then are driven directly from a normal audio amplifier. They have no "steps" (analogue so to speak) and above very low power are a vastly more linear motor for a speaker than most voice coils (and much lower inductance) and the Xmax is only limited by the cone suspension. In terms of a "normal" speaker, a modest size servomotor can be the equal of a very large VC motor. For example a PacSci 4vm62 as we use them has a BL of 27 and Rdc of 2 ohms. For an 8 ohm nominal speaker (Rdc = 6 ohms), this same motor strength would require a BL of 46.7 a figure well beyond any single VC speaker motor I know of. More importantly, suitable motors are frequently available as new surplus for under $100.00 and Nick Mckinney has suitable passives for sale for the "Shiva" and other contraesque designs. While the design is patented, this only prevents one from making and selling them, the individual is always able to build any patented technology for there own use. Build, enjoy, for me, back to working on polar plots. Tom Danley ServoDrive inc / Sound Physics Labs www.servodrive.com ========================================================================= From: "John Hancock" Subject: [JN] Re: Date: Fri, 10 Dec 1999 11:16:07 +0100 Source: Sound Digest Archive v02.n359 Tom Danley wrote: >Crazy idea? no no and I hope I didn't quash your sense of curiosity. Don't worry, I don't discourage that easily. It is just simply not possible given the current state of stepper motor technology. When I was looking at this, the best stepper motor I found had a resolution of 25,000 per turn--approximately 16 bits per 2 revolutions--and a 3,000 rpm rating. That means the maximum frequency at which one could obtain 16 bit resolution with this system is: 3,000 rpm /60 seconds per minute / 2 revolutions / 2pi = 4 Hz Since, in a sealed-box system, for a given output level, excursion is four times smaller for each octave increase in frequency, resolution also falls 2 bits per octave. That means this system would provide only 8 bit resolution at 64 Hz. Now, since human hearing is somewhat poor at these frequencies, 8 bit resolution may not be that bad, but you still need 4 or 5 bits for volume control too. It seems that stepper motor technology is progressing pretty quickly, but it is not "there" yet. Now do the math at 24 bits resolution at 6000 rpm. The maximum frequency that this system can provide 24 bit resolution is: 6,000 rpm / 60 seconds per minute / 2 pi = 16Hz. That means 20 bit resolution at 64 Hz, 18 bit resolution at 128Hz--plenty even losing a few bits for volume control. This would be really simple to implement too--Pacific Scientific already offers a module that converts analog voltage into step-direction commands. The only thing you would have to worry about is some DC drift getting into the system--this system literally has extension to 0 Hz. Perhaps some kind of very-low-frequency filter could be programmed into the voltage-to-step-direction converter. Cost is the other issue of course. I haven't priced the hardware for this, but I'm assuming that it ain't cheap. >You might consider using an "open loop" low inertia DC servomotor as well, they >can be driven with a normal audio signal and if the DCR is ok, then are driven >directly from a normal audio amplifier. Actually that is what I'm working on now. I bought a few Pac Sci motors from C&H Sales after the discussion on the list. I've managed to find a source for Aramid pulley belts right here in Switzerland. I'm planning on ordering some driver frames, surrounds and spiders from Nick McKinney. I'll build the diaphragms and miscellaneous parts out of composites. The only thing I am missing right now are some shaft connecters that match the size of the Pac Sci motor shafts. I'm planning on a sealed two-way system. One driver will operate full range, but at restricted excursion for lower frequencies. The second driver will augment the lower frequencies. This is a bit of a rube goldberg arrangement--your system with the passive radiators is a lot simpler. However, I plan on using DSP to do the equalization and phase compensation and from my experience, this is much easier to do in a sealed system. John ========================================================================= From: "Danielak, Robert M" Subject: [JN] RE: Date: Tue, 04 Jan 2000 09:32:19 -0500 Source: Sound Digest Archive v02.n384 hey blackie, happy new year! how's the new family? please count me in for nynoise. i have a bunch of things i could show and a couple more on the drawing board. there's that bunch of 1626 amps that we took to valerie's but i was thinking of trying the other end of the spectrum this year. instead of the *lowest* power amp maybe we'll shoot for the *highest*... ;) any more thought on the *jam-session* this year. in that case i could bring amps that i made and guitars that rich made... ;) talk to you soon! bob.d. > ---------- > From: blackie[SMTP:tubesville@yahoo.com] > Reply To: blackie@tubesville.com > Sent: Tuesday, January 04, 2000 6:17 AM > To: joe list; me; jc morrison > > howdy joe drinkers > > i am making a last call for submissions to nyNOISE > audio/design exhibition 2000 > > jc and I hope to have some concrete idea of how this > baby is gonna work within a couple of weeks > > just to reiterate: > no special requirements, just try not to be boring > > 2nd Sat of March 2000, jc's loft in hoboken, > attendance by invite, email me with questions or > submissions please... > > thanks > > please note, i will solicit addresses for invites > *after* we sort out the exhibitors...these will be > first come first served, a total of 250 attendees > (all we have room for) > > > > > > > ===== > blackie > blackie@tubesville.com > www.tubesville.com > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://messenger.yahoo.com > ========================================================================= From: Roscoe Primrose Subject: Re: [JN] Re: Date: Mon, 17 Apr 2000 11:57:42 -0400 Source: Sound Digest Archive v02.n523 evaguido wrote: Snip... > > >Besides the first circuitry in the PCM63 after the data input pad is > >some kind of D-type flip flop anyways, probably in a serial to parallel > >converter. > > Yes, and which clock is used to clock that flipflop ? The bit clock. Which is a clock where jitter is much less important. It's the word clock, where all those latched bits are sent simultanously to the DAC that has the most stringent jitter requirements. Peace - -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter "640K ought to be enough for anybody" , Bill Gates, 1981 ========================================================================= From: evaguido Subject: [JN] Re: Date: Mon, 17 Apr 2000 17:34:25 +0200 Source: Sound Digest Archive v02.n523 At 11:24 17/04/2000 +0200, thomas.mayer@philips.com wrote: >Guido, Thomas, >> Agreed but that is in most cases better than forcing another jittery >> current into an IC. Substrate coupling mechanisms then again take care of >> jitter at the conversion..... > >I agree that the conversion process might be influenced by the >way data arrives at it's inputs, via substrate or supply coupling >mechanisms. But to argue if one or the other is better seems to >be speculation to me. I agree. The point is that I cannot find an experiment to separate those.... (reclocking gives additional circuit, non-reclocking may interfere at the substrate level) >One could also argue the other way around, >that a slightly jittery data couples a more smeared out noise >spectrum into the supply than a rigidly reclocked one. Yes, but the lower the energy content of jitter, the better.... >Besides the first circuitry in the PCM63 after the data input pad is >some kind of D-type flip flop anyways, probably in a serial to parallel >converter. Yes, and which clock is used to clock that flipflop ? >So why double up that flip flop outside ? I would think >that the additional flip flop on the board potentially does more harm. I do not know, more than experiments giving preference to "double" reclocking >> But I am not sure if I can get a clock transfered between two boxes, and >> remain the 1 ps jitter requirement > >Huh ??? 1ps jitter requirement ? The whole purpose of my scheme is to >have very relaxed jitter requirements on the interface between DAC >and transport. The 11.289MHz clock has somewhere around 80ns cycle >time. Substracting all the set up and hold timing requirements this >still leaves a HUGE margin for allowable jitter in the 10s of ns range! If you take data correctness as the requirement: Yes At the DAC (20 bits, 8 times oversampled) it needs to be around 1 ps >The resynchronisation mechanism in front of the DAC removes that jitter To what extent ? Sufficient ? How many chokes or additional filters do you have in your amps ? Sufficient ? Have fun Guido >Ciao ... Thomas > > ========================================================================= From: evaguido Subject: Re: [JN] Re: Date: Mon, 17 Apr 2000 20:05:19 +0200 Source: Sound Digest Archive v02.n523 Roscoe Thanks for you reply. I am aware of the importance of the wordclock. However, our ecxperience and measurements show that reclocking any digital (synchronised) signal that enters a PCM63 improves the whole. Given part of my daily work as EMC Engineer (currently on silicon) I am not surprised.... In theory you are right, though practice is different, once many parasitics are involved. regards, - - Guido At 11:57 17/04/2000 -0400, Roscoe Primrose wrote: >evaguido wrote: > >Snip... > >> >> >Besides the first circuitry in the PCM63 after the data input pad is >> >some kind of D-type flip flop anyways, probably in a serial to parallel >> >converter. >> >> Yes, and which clock is used to clock that flipflop ? > >The bit clock. Which is a clock where jitter is much less important. >It's the word clock, where all those latched bits are sent >simultanously to the DAC that has the most stringent jitter >requirements. > >Peace >-- >Roscoe Primrose -- mailto:roscoe@aiko.com -- >http://www.aiko.com/roscoe > >"Once in a while you get shown the light >In the strangest of places if you look at it right." Robert Hunter > >"640K ought to be enough for anybody" , Bill Gates, 1981 > > ========================================================================= From: evaguido Subject: [JN] Re: Date: Sun, 09 Jul 2000 22:47:33 +0200 Source: Sound Digest Archive v02.n599 Andrew It can be done using a voltmeter, but these are also sensitive for the low frequency variations due to the mains variations and/or variations due to the load. These variations are low frequency, making reading difficult. A highpass at 20 Hz or so helps. Easier work is taking an oscilloscope, if you have one at hand. Always realise yourself that high DC voltages may damage the instruments you use: AC coupling using a caacitor may be required. Enjoy = Guido At 13:24 09/07/2000 -0700, Andrew Brandon wrote: >Hi folks, > >How do I measure noise "ripple?" in my power supplies. >Can it be done using a vom? I see where people quote >"10 mv" or whatever figure they have measured. >Thanks > >Andrew > >__________________________________________________ >Do You Yahoo!? >Get Yahoo! Mail – Free email you can access from anywhere! >http://mail.yahoo.com/ > > ========================================================================= From: StepHydro@aol.com Subject: [JN] Re: Date: Fri, 25 Aug 2000 10:41:44 EDT Source: Sound Digest Archive v02.n641 In a message dated 00-08-25 10:23:20 EDT, andersedenholm@cableinet.co.uk writes: << Hi Joes, any one have any info on this tube. Apparantly made by Svetlana. A friend got hold of a bunch, useable for audio? >> Anders, I suspect that is a great tube. Uhhhhh, does it have a type identifier???? Cheers/Carron :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) :-) ========================================================================= From: Roscoe Primrose Subject: [JN] Re: Date: Fri, 15 Dec 2000 14:05:25 -0500 Source: Sound Digest Archive v02.n760 TORSTEN.LOESCH@enhar-ha.nthames.nhs.uk wrote: > Quite impressive for a box of tricks costing less than $ 1,000. BTW, in a digital loop between CD > Transport and DAC the UC is essentially sonically neutral, without audible contribution unless the EQ is > employed. I'm currently running my BSS OmniDrive Compact Plus directly from the digital out on my transport with similarly good results. Unfortunately, the BSS doesn't have digital outs (yet, I plan to take a look inside about providing three after the new year) but it is still quite neutral. Havn't played with the analog ins yet, have to finish my Teres first... > So for anyone with Fullrange drivers that have sonic problems with their response and room in a fu lly > digital system with separate X-Port and DAC I cannot recommend the UC high enough. For a prima rily I'd been thinking the same thing, but hadn't been willing to shell out the bucks to find out. > analogue system like my own the case is not as clear-cut. The Converters and analogue stages in th e UC > should ideally be a lot better, though they seem adequate. One could of course use true high resolution > external converters if one wants to, looking at the Datasheets it seems that especially the D2A > converter used in the UC is the limiting factor to sound quality. I'd also thought about that. I don't think I will use an external A/D converter with the BSS, at least not initially, it operates at 96/24 (probably more like 20bits useable) from analog inputs, so I'll see how that works out first. Peace - -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter "640K ought to be enough for anybody" , Bill Gates, 1981 ========================================================================= From: sschenkel@juno.com Subject: [JN] Re: Date: Sun, 17 Dec 2000 21:08:59 -0800 Source: Sound Digest Archive v02.n762 Does that include speakers too? Schenkelini On Sun, 17 Dec 2000 10:25:57 -0800 (PST) blackie writes: > An Open Invitation to Designers… > > …to submit work for inclusion in a new Audio/Design > Collection, showing in a large finished loft space / > listening room in Hoboken. The work will be offered > for sale to the listening public on a consignment > basis. > > I am opening this space as an alternative to > traditional high end audio stores. It will be called > NOISE Audio/Design Space (NADS), and is not directly > affiliated with nyNOISE Audio Design Exhibition. Our > primary purpose will be to provide an outlet for the > sale of work built by designers outside the existing > commercial audio structure. Our secondary purpose > will be to foster dialog, exchange of ideas, and > possible collaboration among the underground design > community. > > It is my feeling that there is an untapped market for > audio / design that is unencumbered by the typical > corporate approaches of "cost vs. price" analysis, > committee based design decisions, and mass > marketability - alternative designs informed mainly > by a pursuit of sonic excellence and personal > aesthetics. My goal will be to select a group of this > work and provide a context for the work based on the > artist / gallery model rather than the traditional > corporation / retail store system. It is my hope that > press and public will respond positively. > > Any designers interested in being considered for > inclusion in this venture, please contact me by email > for particulars. > > Thanks- > Blackie Pagano > blackie@tubesville.com > www.tubesville.com > > ===== > blackie > blackie@tubesville.com > www.tubesville.com > > __________________________________________________ > Do You Yahoo!? > Yahoo! Shopping - Thousands of Stores. Millions of Products. > http://shopping.yahoo.com/ > > ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/tagj. 0000 ========================================================================= From: "Multi-Volti Devices" Subject: [JN] 0.1 uF 450 v~ (that's vac) paper in mineral oil Date: Mon, 19 Apr 1999 03:34:57 -0400 Source: Sound Digest Archive v02.n129 Hello: I have some NOS Matsushita Industrial paper in mineral oil (labeled no PCB's) capacitors, 0.1 uF 450 Vac. Ceramic body, fairly long leads. A friend who is a capacitor applications engineer with a large film cap company estimates a 'good quality' 450 vac part may have a DC rating as high as 1100 VDC. I am pondering how I can safely test these to estimate a DC rating. I don't have access to a current limited DC hi-pot (dielectric withstand) tester (only have access to an ac unit, which would just ruin the parts). I was hoping I could observe leakage current at increasingly higher voltages (analogous to diode reverse breakdown), and stop increasing voltage when I start to get a change in IDC. Any ideas on how to estimate the DC capability, and any ideas what would be a fair (to me) price to sell some for? I have more than I anticipate needing, but don't want to 'give them away' naively. I'd like to get a fair price for them. (Roughly 60-70 left). Thanks Murray ========================================================================= From: Remco Stoutjesdijk Subject: [JN] 01 vs 26 ? Date: Tue, 24 Apr 2001 15:27:58 +0200 Source: Sound Digest Archive v02.n873 Hi, Whilst pondering a new preamp and trying to decide which tube to use, I noticed the many similarities between the 01 and the 26. However while the 26 is used in a lot of preamps, I hardly ever see the 01. Why? From the datasheet it seems just a bit more fragile, but in preamps it should work just fine. I have a pair of 301s that measure and match very well and seem fine candidates for a nice WVOT preamp. Unless... well, I'm curious why not! Regards, Remco - -- http://www.ultranalog.com ========================================================================= From: Jim de Kort Subject: Re: [JN] 01 vs 26 ? Date: Tue, 24 Apr 2001 17:05:02 +0200 Source: Sound Digest Archive v02.n874 Hoi Remco, Whilst pondering a new preamp and trying to decide which tube to use, I >noticed the many similarities between the 01 and the 26. However while >the 26 is used in a lot of preamps, I hardly ever see the 01. Why? From >the datasheet it seems just a bit more fragile, but in preamps it should The 01A is very similar to the 30, Rp of 10K etc... Jim de Kort jim@vt52.com http://www.vt52.com http://www.ux226.com ========================================================================= From: SBench@aol.com Subject: Re: [JN] 01 vs 26 ? Date: Tue, 24 Apr 2001 22:12:13 EDT Source: Sound Digest Archive v02.n874 In a message dated 01-04-24 09:31:29 EDT, remco@ultranalog.com writes: > Whilst pondering a new preamp and trying to decide which tube to use, I > noticed the many similarities between the 01 and the 26. However while > the 26 is used in a lot of preamps, I hardly ever see the 01. Why? Hi, In addition to the excellent notes also posted, I've found the 01A to be better sounding than 26, but only when operated on reduced filament voltage. (see distortion curves of 01A starved filament on my web pages at http://members.aol.com/sbench101) 01A is sometimes harder to find, and it can be a bit microphonic, but very nice sounding. Best Regards, Steve ========================================================================= From: William Gardner Subject: [JN] 025 sale Date: Sun, 02 Jan 2000 23:29:30 -0600 Source: Sound Digest Archive v02.n559 For sale : Pair magnequest 025 OPT . New . $225.00 Thanks William Gardner ========================================================================= From: peufeu@free.fr Subject: [JN] $0.5 cable recipe Date: Fri, 22 Dec 2000 15:53:50 +0100 (MET) Source: Sound Digest Archive v02.n768 Hi people, This is a mad scientists' recipe for strange, yet interesting, audio cables : ingredients : - uninsulated plain standard copper wire from the junk pile (or strip the insulation from an insulated wire) - some of this PCB breadboard which you use for wrapping and making prototypes that smoke in the making : - cut small chunks of breadboard, rectangular pieces of about 1.5 cm. long and 3 mm wide (with just one row of holes in the middle). - cut your wire in 2 equal lengths, then thread the little PCB rectangles on it, using them as spacers to keep the two wires apart (put each wire in the holes at each side) - solder the wire to the breadboard pieces to make the thing hold together nicely Now you have two bare wires kept apart by little spacers. If you want a stereo cable, you can do it with three wires, with ground in the center of the spacers. Twist it so the wire pair does a half turn for every spacer (there should be one every 10 cm or so) Solder it to your favorite connectors and listen !!! I won't tell you how it sounds. It is interesting. Given the cost, I encourage everybody to try this and report your experiences on the mailing list... You can also do this with your speaker cables (no shieldong problems), your power supplies, etc... Have fun, and merry christmas ! ========================================================================= From: "Joerg Heyer" Subject: [JN] 0.5 F Capacitors (16V) Date: Thu, 28 Sep 2000 16:14:22 EDT Source: Sound Digest Archive v02.n677 Hi, does anybody know a source for large value capacitators (o.33 - 1F) which are, *aehemm*, cheap (the schematic calls for 4 of them)? Thanks Joerg _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. ========================================================================= From: "David R. McGown" Subject: Re: [JN] 0.5 F Capacitors (16V) Date: Thu, 28 Sep 2000 19:13:07 -0400 (EDT) Source: Sound Digest Archive v02.n677 On Thu, 28 Sep 2000, Joerg Heyer wrote: Try an shop specializing in automobile sound. Here in the US, Parts Express carries 1F capacitors as storage caps for high power custom auto sound installations. They have to be at least 12V. Also, I think Panasonic has some 1F 5V caps for computer power storage, if they are cheap enough you can always use 3 in series to get 15V. These are available from Digikey. David > Hi, > > does anybody know a source for large value capacitators (o.33 - 1F) which > are, *aehemm*, cheap (the schematic calls for 4 of them)? > > Thanks Joerg > _________________________________________________________________________ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. > > Share information about yourself, create your own public profile at > http://profiles.msn.com. > ====================================================================== David R. McGown dmcgown@megacats.com -o-O-o- Home: (301)946-3027 13100 Wilton Oaks Dr. Work: (703)416-1240 Silver Spring, MD 20906 ========================================================================= From: evaguido Subject: Re: [JN] 0.5 F Capacitors (16V) Date: Fri, 29 Sep 2000 09:26:03 +0200 Source: Sound Digest Archive v02.n678 Joerg do you realy mean 1 F ? The only onesd I know are back ups for RAM memory. These are 5.5 V, not cheap and I use them as back up in the backlight of bikes.... Guido At 16:14 28/09/2000 EDT, Joerg Heyer wrote: >Hi, > >does anybody know a source for large value capacitators (o.33 - 1F) which >are, *aehemm*, cheap (the schematic calls for 4 of them)? > >Thanks Joerg >_________________________________________________________________________ >Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. > >Share information about yourself, create your own public profile at >http://profiles.msn.com. > > > ========================================================================= From: "Joerg Heyer" Subject: Re: [JN] 0.5 F Capacitors (16V) Date: Sat, 30 Sep 2000 14:36:02 EDT Source: Sound Digest Archive v02.n681 Hi, thanks for the help and suggestion! Since finally taking a plunge at analog again, I settled on the Hiraga MC - -prepre for a starter for my (yet to order) Denon DL103. The schematics can be found at the Bonavolt website http://www.infomaniak.ch/~bonavolt/prepre.htm. The caps 16V 0.5 F are for the battery power supply ( I like the idea of being independent of the power line, I hope to avoid electroexecuting me on my first non kit amp project). I will try other power supplies later but I wanted to start with a "original proven" design. Joerg _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com. ========================================================================= From: "P. Caillaud" Subject: Re: [JN] 0.5 F Capacitors (16V) Date: Sat, 30 Sep 2000 23:57:14 +0200 Source: Sound Digest Archive v02.n681 Hi, If I can be of any advice, you don't need such a huge capacitance when using battery power supply. Batteries are slow, but not to the point of putting caps that can keep the amp running for several minutes once you unplug the batteries... It looks like overkill to me. Having good quality caps is more important than having 1 Farad. I would suggest low inductance 63000 uF types with MKP bypassing and anti-vibration treatment (all caps are microphonic, some more than others). This will save you much dough, that you will re-invest at once in MAT-03 precision matched low-noise transistor pairs to replace the BC560C's. Overall you should get much better performance from this. Good luck ! Joerg Heyer wrote: > Hi, > > thanks for the help and suggestion! > > Since finally taking a plunge at analog again, I settled on the Hiraga MC > -prepre for a starter for my (yet to order) Denon DL103. > The schematics can be found at the Bonavolt website > http://www.infomaniak.ch/~bonavolt/prepre.htm. > > The caps 16V 0.5 F are for the battery power supply ( I like the idea of > being independent of the power line, I hope to avoid electroexecuting me on > my first non kit amp project). I will try other power supplies later but I > wanted to start with a "original proven" design. > > Joerg > > _________________________________________________________________________ > Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. > > Share information about yourself, create your own public profile at > http://profiles.msn.com. - -- _________________________ Pierre-Frédéric Caillaud peufeu@free.fr 32 Passage Gonin 69001 Lyon France 06 61 52 75 96 04 78 43 15 94 1111 ========================================================================= From: "Greg Monfort" Subject: "100+dB / 1W speaker". Was: Fw: [JN] System 1:Step 4, Speakers........... Date: Fri, 11 Feb 2000 14:10:19 -0500 Source: Sound Digest Archive v02.n445 Hi, I guess I should have changed the subject line to: "100+dB / 1W speaker". I was 'thinking out loud' so to speak WRT Peter's desire for a 1W ~full range speaker. I couldn't sleep and found it an interesting diversion. WRT the System 1, I'm for a two way horn system down to ~100Hz, with a multiple driver bass unit to keep the size semi-reasonable, but after witnessing the BassList Speaker design forum / fiasco I'm steering clear of this one too. :^)) - ------------- Jean-Michel Le Cleac'h wrote: > > While necessary, frequency response and cut-off slope are not the only > things to consider. ======== You bet! Amplitude, phase shift, etc. ======== > How is the impedance inside the reproduced interval of frequency? is > another important question. ======== Why so in a wide range driver? ======== > Also a TEF to look for possible parasitic resonnances (inside the air > volume between basket and membrane, inside the basket,etc.) is necessary. ======== This is well beyond my capabilities at present, and normally isn't considered in most DIY, but would be nice. ======== > IMHO our Joenet's loudspeakers system should present a constant impedance > from 100Hz to 10000Hz. ======== I'm not sure why, with my idea at least, but a zobel should take care of it. - ------------- Gordon wrote: > Actually if you had the T/S parameters for this you would know that it > would be more like 0.7CUf and tuned to 125 is about as low as you can go. ======== Again, if the info at http://www.netspace.or.jp/~eifl/eifl/export/export2.htm is fairly accurate, Vas Qes, Qms can be guesstimated from it's Qts, Sensitivity ratings. With my assumptions, BoxPlot predicted close enough to your numbers for a Q =.7 box, but that's hardly all the BW this puppy can do, or any other driver for that matter. With a power limited EBS (extended bass shelf) alignment (and <2W is pretty limited IMO!) there's lots more usable BW to be had, especially when a second driver of the same type is added to help fill in the bottom octaves. A little room gain helps to finish it off. An EBS also lowers system Q, reduces phase shift, and gives a ~flat amplitude response over a wider BW (with a second driver). It's my understanding, and experience, that these are all pluses in the pursuit of accurate sound reproduction. Tradeoffs are dramatically increased box size, non flat FR, though in this design I see neither one being an issue. TIA for more insight, GM ========================================================================= From: "Le Cleac'h Jean-Michel" Subject: Re: [JN] 100 mu.sec. square wave - RIAA filtered Date: Thu, 16 Nov 2000 18:35:32 +0100 Source: Sound Digest Archive v02.n735 This is a multi-part message in MIME format. - ------=_NextPart_000_000F_01C04FFC.0048D560 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Hello, As since several days it is very difficult to use xdrive from France, I send to the whole list a very small attachment (4.71k) that contains a 2 color .gif graph showing a part of a square signal through an inverse RIAA network (the one I described previously). I could have shown the result of a longer duration square signal but in fact it only differs by the length of the nearly horizontal part of the signal, so you can easily prolongate linearly the actual signal to obtain a longer one. 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[JN] 100W AKSA Amp Date: Fri, 24 Aug 2001 11:05:48 -0400 Source: Sound Digest Archive v02.n954 Hi all, Wondering if anyone on the list has already own one. How does it match up to the 55 watter? - -- Johari Yip =================== j45yip@netscape.net =================== __________________________________________________________________ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buy ing online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/ ========================================================================= From: Larry Van Wormer Subject: [JN] $10 CDnow coupon Expires 2/15 Date: Wed, 10 Feb 1999 20:45:37 -0500 Source: Sound Digest Archive v02.n040 http://www.cdnow.com/cgi-bin/mserver/redirect/leaf=from=vbd:u:imu:nht:d A nice deal, $10 off an order of $20 or more. I just ordered a couple of CD's using it. Larry Van Wormer ========================================================================= From: Allen Wright Subject: [JN] 10" driver recommendation? Date: Fri, 23 Apr 1999 04:37:05 -0400 Source: Sound Digest Archive v02.n130 Lady and Gents, Following a failed commercial venture, a good friend has a pair of impressive looking (and very expensive) 70 liter speaker boxes needing a suitable full range/coaxial 10 inch driver, hopefully of highish dB/watt sensitivity. I have suggested the Tannoy 10" coaxial, going on the 12's and 15's I have heard and liked very much. But I have never heard them. Any ear reports on the 10", or any other suggestion? The boxes are currently sealed, but a reflex port could easily be fitted, conversion to a horn (front or rear) is not possible... The box design will not allow a separate tweeter and still look as stunning as it does, hence the full range/coax request. Thanks in advance for any experiences/suggestions. A European sourced device would be preferred but is not essential. Allen (VSE) PS We have a REAL web address now: www.vacuumstate.com ========================================================================= From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" Subject: Re: [JN] 10" driver recommendation? Date: Fri, 23 Apr 1999 20:06:43 +0200 Source: Sound Digest Archive v02.n130 Hello Allen, all,- Allen Wright wrote: > Lady and Gents, > Following a failed commercial venture, a good friend has > a pair of impressive looking (and very expensive) 70 liter > speaker boxes needing a suitable full range/coaxial 10 inch > driver, hopefully of highish dB/watt sensitivity. > > I have suggested the Tannoy 10" coaxial, going on the 12's > and 15's I have heard and liked very much. [snip!] I don't get to post or participate much these days,-(The family + I is moving to a new appartment,-so I'm buried in my junk and stash these days, trying to sort through it.....(wondering what evil childhood experiences that made me collect all this junk..) But,-amongst that is a pair of the 10" 'er Goodmans axiom 80. (Mine are not for sale..Took me 10 years to get an old pair..) IMNHO this is easily the most well-balanced, musical and extended full-range driver I've yet experienced,- I think it beats the Lowther-consept clearly,-when it comes to balance, versatility,finesse,-especially on vocal.But they are *somewhat* thin in the bass,-Not much there as the cantilever surround makes for an extremely low Fres ,-with a following very lo-Q. If they still are made I don't know,- but Godmans produced a series for the Asian marked in the mid/late eighties I think. At that time it was possible to get these in Denmark,- for approx. 2400 Dkr. each? (Kurt?) Maybe other know something on the wherabouts of the Axiom 80's these days? My 2 oeres worth. (100 oere=1 Nok= 0,128 USD) Regards Torbjoern Lien, Norway > > > > ========================================================================= From: Allen Wright Subject: Re: [JN] 10" driver recommendation? Date: Sun, 25 Apr 1999 07:20:28 -0400 Source: Sound Digest Archive v02.n131 Torbjoern wrote: >>>But,-amongst that is a pair of the 10" 'er Goodmans axiom 80. (Mine are not for sale..Took me 10 years to get an old pair..) IMNHO this is easily the most well-balanced, musical and extended full-range driver I've yet experienced,- I think it beats the Lowther-consept clearly<<< I know them well, and almost had a pair for myself - but the seller pulled out of the deal when he found what these puppies are worth in Japan! They do sound beautiful but would be far too fragile for my friends usage, he tends to play things loud. Great suggestion though! Allen (VSE) PS Anyone heard a Tannoy 10" coax? ========================================================================= From: Torsten.Loesch@enhar-ha.nthames.nhs.uk Subject: Re(2): [JN] 10" driver recommendation? Date: 26 Apr 1999 11:15:32 +0000 Source: Sound Digest Archive v02.n131 Hi there, Allen (VSE) wrote: > PS Anyone heard a Tannoy 10" coax? I have (fairly regulary actually) heard the Tannoy 10" Units for Studio-use.... Reasonably nice, but not great.... How about trying these Boxes with a Normal decent Wideband 10" (JBL 2123?) and a Horn sitting on top of them.... I know - boring, but works well.... Later Thorsten ========================================================================= From: "Craig Anderson" Subject: Re: [JN] 10k:10k input tranny? Date: Fri, 31 Aug 2001 21:42:19 -0600 Source: Sound Digest Archive v02.n958 Funny you should ask, I placed an order for one of these today: WSM 10k/10k 0.5 Watt Matching Transformer 10k ohms to 10k ohms http://www.edcorusa.com/magnetics/audio/WSM/WSM10k-10k.htm $7.56 My first purchase here, they have an 800 order line and sold me qty 1. I'm planning to build a single channel headphone amp and try one of these for a stereo to mono input. EM6410 Stereo to Mono Coupling Transformer Stereo line level to mono line level $7.09 - ----- Original Message ----- From: "Steven S" To: Sent: Friday, August 31, 2001 8:38 PM Subject: [JN] 10k:10k input tranny? > > Anyone know where i can get a small and/or good 10k:10k input > tranny. Putting together a headphone amp to fiddle with and i cant seem to > find what i'm looking for from the usual sources. > > > > Steven St.Laurent ::: stevensl@mindspring.net ::: 403forbidden.net > > "Outlook not so good." > That magic 8-ball knows everything! > I'll ask about Exchange Server next. > > > ========================================================================= From: Steven S Subject: [JN] 10k:10k input tranny? Date: Fri, 31 Aug 2001 22:38:35 -0400 (EDT) Source: Sound Digest Archive v02.n958 Anyone know where i can get a small and/or good 10k:10k input tranny. Putting together a headphone amp to fiddle with and i cant seem to find what i'm looking for from the usual sources. Steven St.Laurent ::: stevensl@mindspring.net ::: 403forbidden.net "Outlook not so good." That magic 8-ball knows everything! I'll ask about Exchange Server next. ========================================================================= From: "Ellen Oler" Subject: [JN] 10 monkeys eat a free lunch Date: Sun, 05 Nov 2000 22:09:16 -0500 Source: Sound Digest Archive v02.n722 I *think* that what would happen is that they would reach an equilibrium somewhere. You couldn't hold either tube to a fixed op point as if it were attached to a stiff supply, you could just get it set to a desired op point by experimentation, I imagine. Imagine using one of the Doc B C4S boards set to 30mA instead of another tube. Well, the tube attached to the C4S would reach an equilibrium where it was drawing the current it was permitted to draw - the DC op point would be forced to shift - I think??? With the two tubes I imagine the voltage drop across each one would shift (from where it would be otherwise in a "free running" setup) until they were both working at the same current. What this does to the sound of course is anybody's guess. In fact the whole thing is just a guess . . . I bet as you twiddled that 300 ohm pot you'd get the cathode of the 10 running up and down to adjust. Sounds like a fun sport! - -j, voting for Al (M.? G.?) in a couple of days, then breathlessly awaiting the Canadian results >what happens if one of the tubes is not matched in current draw to the other? > >in otherwords, if the 10 is running 30ma and the 6c45 is biased to run >35ma??? or take it the other way and let the 10 run 35ma and the russkie >only lets 30ma go through... > >well we know both tubes will have the same current, the question becomes is >that how much current they would be running if the other tube were not >there? > >its an interesting question, what happens to a tube when you force it away >from its characteristics? can this be done... > >i bet a small say 300 ohm or so pot in series with the choke will let you >tune the sound and nail the operating point... and a 500 ohm DCR choke is >easy enough to source for this... otherwise you got 6500 turns of #35 on an >EI87 nickel core.... > >in any event at some point one of the tubes is gonna current limit the >other... ========================================================================= From: "Epstein, Jeremy" Subject: [JN] 10 monkeys eat a free lunch - design idea/questions Date: Fri, 3 Nov 2000 10:16:03 -0500 Source: Sound Digest Archive v02.n720 Design idea: Monkey amp using 10 tube driven by 6C45Pi. Both run at 35mA, so no need for a seperate cathode resistor from the cathode of the 10 to ground: all the 10's juice flows through the driver tube. Design questions: Does there need to be a bypass cap from the cathode of the 10 to prevent regeneration? As I look at it, the driver tube would serve as a cathode impedance for the 10 equal to the vector sum of the impedance of the driver load choke plus the plate impedance of the driver tube plus any resistance needed in series to get correct bias (does some portion of this get multiplied by the mu of the bottom tube too?) hence the 10 would suffer a large amount of regenerative feedback. True or false? Also as I see it, the bypass could either go from cathode to B+ a la Ultrapath or cathode to ground as is more conventionally done. True or false or not necessary because the first answer is "false"? If the bypass cap is necessary would it need to be largish (because the total cathode impedance is smallish, say <2K) or small (because there is in fact a "times mu" term that makes the effective impedance large)? Proposed schematic for reference: (fixed width font please): B+ | C|C---> C|C C|C---> | 10 _|_ ...-----+ /^\ | | | | UUU | bypass?----* | (* = center tap of filament < | transformer) DCR < | of this < | R and | | choke C| | totals C| | ~860 C| | +------+ 6C45Pi _|_ - -----+-----... C| --, C| | C| _|_ C| - | | 2 x AA battery V _|_ - | V Note that this could be built as a one-resistor per channel amp (grid stopper on 6C45pi), if a battery is used to bias the driver and the plate choke DCR is made 860 ohms, and a grid choke is used on the input. Figure a filtered supply of 595 V, drop 5V in the OPT, drop 395 across the 10, drop 30 (DCR = 860, I = 35mA) to the plate of the 6C45Pi where the voltage will be 165V. (I got this 10 op point from a Joe who oughta know.) - -j ========================================= Jeremy Epstein........jepstein@ndbcap.com ========================================= ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 10 monkeys eat a free lunch - design idea/questions Date: Fri, 3 Nov 2000 11:20:09 EST Source: Sound Digest Archive v02.n720 - --part1_db.bbbb1b8.27343fb9_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Hi If you replace the two AA batterries with a 6AS7 with its grip tied to the plate (as a diode), you can live without the bypass C. In my amp, the 6AS7 so wired drops 4.4 volts at 40 mA, so it will be fairly close at 35 mA. Happy Ears! Al B^} - --part1_db.bbbb1b8.27343fb9_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit Hi

If you replace the two AA batterries with a 6AS7 with its grip tied to the
plate (as a diode ), you can live without the bypass C.

In my amp, the 6AS7 so wired drops 4.4 volts at 40 mA, so it will be fairly
close at 35 mA.

Happy Ears!
Al        B^}

- --part1_db.bbbb1b8.27343fb9_boundary-- ========================================================================= From: "Epstein, Jeremy" Subject: RE: [JN] 10 monkeys eat a free lunch - design idea/questions Date: Fri, 3 Nov 2000 12:06:43 -0500 Source: Sound Digest Archive v02.n720 > Hi Jeremy, > > wow, a tube related technical question on the JoeNet, > long time no see. Sorry. DEMOCRACY SUCKS!! UP WITH IMPERIALISM!! JUST BECAUSE YOU'RE PARANOID DOESN'T MEAN THEY'RE *NOT* OUT TO GET YA!! SEX PISTOLS RULE!! Better? > >Monkey amp using 10 tube driven by 6C45Pi. Both run at 35mA, > so no need for > >a seperate cathode resistor from the cathode of the 10 to > ground: all the > >10's juice flows through the driver tube. > > Sounds like a nice idea! I got some VT-25's for my birthday, hence the thought. > >Does there need to be a bypass cap from the cathode of the > 10 to prevent > >regeneration? > > Absolutely. You will get no output signal from this amp > without a cathode bypass. OK. > >If the bypass cap is necessary would it need to be largish > (because the > >total cathode impedance is smallish, say <2K) > > If memory serves me right then the impedance seen when > looking into the cathode is (Rp+Ra)/(mu+1). > The size of bypass cap needed will a bit less then in a conventional > cathode biased stage but not by much so. So pretty large the way I like to do it, say 100uF or thereabouts. > I hope the AA-batteries you mentioned in your schematic consists > of NiCd cells. Normal batteries will blow up! But of course! Anecdotal research shows that NiCads will survive 70mA of charging current for at least many months. Thanks Manfred! - -j ========================================= Jeremy Epstein........jepstein@ndbcap.com ========================================= ========================================================================= From: "Larry D. Moore" Subject: Re: [JN] 10 monkeys eat a free lunch - design idea/questions Date: Fri, 03 Nov 2000 12:33:30 -0500 Source: Sound Digest Archive v02.n720 Don't like monkey amps. Tried it. It simply moves the problem from one location in the circuit to another. Think making the cathode bypass cap the most critical component in the amp signal section. To me, do seperate supplies, diode bridge, or a cap. I mean I'd rather pick a low value cap that sounds good than a big one that sounds bad. Think 0.1uF versus several orders of magnitude bigger. Granted it will change the soundstage, but if you listen long enough it is simply wrong. LDM At 10:16 AM 11/3/00 -0500, you wrote: >Design idea: > >Monkey amp using 10 tube driven by 6C45Pi. Both run at 35mA, so no need for >a seperate cathode resistor from the cathode of the 10 to ground: all the >10's juice flows through the driver tube. > >Design questions: > >Does there need to be a bypass cap from the cathode of the 10 to prevent >regeneration? As I look at it, the driver tube would serve as a cathode >impedance for the 10 equal to the vector sum of the impedance of the driver >load choke plus the plate impedance of the driver tube plus any resistance >needed in series to get correct bias (does some portion of this get >multiplied by the mu of the bottom tube too?) hence the 10 would suffer a >large amount of regenerative feedback. True or false? > >Also as I see it, the bypass could either go from cathode to B+ a la >Ultrapath or cathode to ground as is more conventionally done. True or false >or not necessary because the first answer is "false"? > >If the bypass cap is necessary would it need to be largish (because the >total cathode impedance is smallish, say <2K) or small (because there is in >fact a "times mu" term that makes the effective impedance large)? > > >Proposed schematic for reference: > >(fixed width font please): > > > B+ > | > C|C---> > C|C > C|C---> > | > 10 _|_ > ...-----+ > /^\ | > | | | > UUU | > bypass?----* | (* = center tap of filament > < | transformer) > DCR < | > of this < | > R and | | > choke C| | > totals C| | > ~860 C| | > +------+ > 6C45Pi _|_ >-----+-----... > C| --, > C| | > C| _|_ > C| - > | | 2 x AA battery > V _|_ > - > | > V > > >Note that this could be built as a one-resistor per channel amp (grid >stopper on 6C45pi), if a battery is used to bias the driver and the plate >choke DCR is made 860 ohms, and a grid choke is used on the input. > >Figure a filtered supply of 595 V, drop 5V in the OPT, drop 395 across the >10, drop 30 (DCR = 860, I = 35mA) to the plate of the 6C45Pi where the >voltage will be 165V. (I got this 10 op point from a Joe who oughta know.) > >-j > >========================================= >Jeremy Epstein........jepstein@ndbcap.com >========================================= > > ========================================================================= From: MHuber@t-online.de (Manfred Huber) Subject: Re: [JN] 10 monkeys eat a free lunch - design idea/questions Date: Fri, 03 Nov 2000 17:48:52 +0100 Source: Sound Digest Archive v02.n720 Hi Jeremy, wow, a tube related technical question on the JoeNet, long time no see. >Monkey amp using 10 tube driven by 6C45Pi. Both run at 35mA, so no need for >a seperate cathode resistor from the cathode of the 10 to ground: all the >10's juice flows through the driver tube. Sounds like a nice idea! >Does there need to be a bypass cap from the cathode of the 10 to prevent >regeneration? Absolutely. You will get no output signal from this amp without a cathode bypass. Imagine you sit in the #10 and lock out through the cathode wire. What do you see first? The choke! This means there is a very large ac impedance in between the cathode and GND. The other way around: Imagine a signal on the plate of the 6C45. This signal is also on the grid of the #10. Because of the choke there is no ac current through the tubes and the #10 cathode will follow it's grid! Viewed from this perspective it looks like a 'choke-enhanced' SRPP stage. The bypass cap 'shorts' the #10 cathode to gnd and thus allows the #10 to modulate it's plate current. >As I look at it, the driver tube would serve as a cathode >impedance for the 10 equal to the vector sum of the impedance of the driver >load choke plus the plate impedance of the driver tube plus any resistance >needed in series to get correct bias (does some portion of this get >multiplied by the mu of the bottom tube too?) hence the 10 would suffer a >large amount of regenerative feedback. True or false? Exactly true! >Also as I see it, the bypass could either go from cathode to B+ a la >Ultrapath or cathode to ground as is more conventionally done. True or false True. >If the bypass cap is necessary would it need to be largish (because the >total cathode impedance is smallish, say <2K) If memory serves me right then the impedance seen when looking into the cathode is (Rp+Ra)/(mu+1). The size of bypass cap needed will a bit less then in a conventional cathode biased stage but not by much so. I hope the AA-batteries you mentioned in your schematic consists of NiCd cells. Normal batteries will blow up! Regards Manfred - ------------------ Manfred Huber MHuber@t-online.de - ------------------ ========================================================================= From: dslagle@earthlink.net (dave slagle) Subject: Re: [JN] 10 monkeys eat a free lunch - design idea/questions Date: Fri, 3 Nov 2000 13:31:43 -0500 Source: Sound Digest Archive v02.n721 hey j, what happens if one of the tubes is not matched in current draw to the other? in otherwords, if the 10 is running 30ma and the 6c45 is biased to run 35ma??? or take it the other way and let the 10 run 35ma and the russkie only lets 30ma go through... well we know both tubes will have the same current, the question becomes is that how much current they would be running if the other tube were not there? its an interesting question, what happens to a tube when you force it away from its characteristics? can this be done... i bet a small say 300 ohm or so pot in series with the choke will let you tune the sound and nail the operating point... and a 500 ohm DCR choke is easy enough to source for this... otherwise you got 6500 turns of #35 on an EI87 nickel core.... in any event at some point one of the tubes is gonna current limit the other... i would be interested to hear what the tone "pot" does to the sound... and who knows... maybe it will all just fall perfectly into place... tubes have a funny way of doing that. dave >> >> >> B+ >> | >> C|C---> >> C|C >> C|C---> >> | >> 10 _|_ >> ...-----+ >> /^\ | >> | | | >> UUU | >> bypass?----* | (* = center tap of filament >> < | transformer) >> DCR < | >> of this < | >> R and | | >> choke C| | >> totals C| | >> ~860 C| | >> +------+ >> 6C45Pi _|_ >>-----+-----... >> C| --, >> C| | >> C| _|_ >> C| - >> | | 2 x AA battery >> V _|_ >> - >> | >> V >> >> ========================================================================= From: Paul Joppa Subject: Re: [JN] 10 monkeys eat a free lunch - design idea/questions Date: Fri, 03 Nov 2000 17:41:03 -0800 Source: Sound Digest Archive v02.n721 > From: "Epstein, Jeremy" > Design idea: > > Monkey amp using 10 tube driven by 6C45Pi. Both run at 35mA, so no need for > a seperate cathode resistor from the cathode of the 10 to ground: all the > 10's juice flows through the driver tube. > > Design questions: > > Does there need to be a bypass cap from the cathode of the 10 to prevent > regeneration? As long as the output signal current goes through the cathode circuit to ground (then through the power supply back to the output transformer and tube), it needs to be bypassed. With parallel feed or ultrapath, the signal current in the midband can be kept out of the cathode to ground path and the bypass cap is not needed. I have talked briefly with two people who have tried parafeed with and without the cathode bypass cap; both thought it sounded better (had better bass) with the cap. It might have worked better if the parafeed/ultrapath cap were as large as a bypass cap, like 220uF instead of 2.2uF. I have not heard from anyone who has tried this yet though - I say, go for it, Jeremy! and tell us what happened... Another way to look at it - without a bypass it is a mu follower of the amplified choke variety (an SRPP with a choke for the upper bias resistor). This is a great driver circuit, with output taken from the lower plate. Or, take it from the upper cathode as a cathode follower output, cap coupled to an interleaved output transformer. Kind of a mutant spud... > If the bypass cap is necessary would it need to be largish (because the > total cathode impedance is smallish, say <2K) or small (because there is in > fact a "times mu" term that makes the effective impedance large)? Like any other cathode bypass cap, it should be large enough to have a small impedance relative to the rest of the output signal current loop. In addition, if the cathode impedance is to be kept small enough to not affect the 10's operation, the cathode impedance should be small relative to the 10's cathode impedance which is on the order of 1/gm. > Note that this could be built as a one-resistor per channel amp (grid > stopper on 6C45pi), if a battery is used to bias the driver and the plate > choke DCR is made 860 ohms, and a grid choke is used on the input. So use a ferrite bead on that grid! :^) - -Paul Joppa ========================================================================= From: Rich Conte Subject: [JN] 10 Tube, VT25 DC Coupled driven by 6sn7 Date: Fri, 09 Feb 2001 21:24:41 -0500 Source: Sound Digest Archive v02.n802 Dear Folks, I just installed 2 - 10's running only 6.3 V AC Filament supply v. req. 7.5 and do they ever sound good, just DC coupled via 6SN7's, rectifier is GZ37 and outputs are NOS. Anyone use these, they are the BRIGHTEST filaments I've seen, look like Svetlana Triodes. The tubes GE VT25 and RCA VT25...even at 5.0 V AC they are wonderful. The plates run about 305VDC and current about 20mA. Cheers,. ========================================================================= From: SBench@aol.com Subject: Re: [JN] 10 Tube, VT25 DC Coupled driven by 6sn7 Date: Fri, 9 Feb 2001 21:46:59 EST Source: Sound Digest Archive v02.n803 In a message dated 01-02-09 21:28:51 EST, rconte@attglobal.net writes: > I just installed 2 - 10's running only 6.3 V AC Filament supply v. req. > 7.5 and do they ever sound good, just DC coupled > via 6SN7's, rectifier is GZ37 and outputs are NOS. > > Anyone use these, they are the BRIGHTEST filaments I've seen, look like > Svetlana Triodes. > > The tubes GE VT25 and RCA VT25...even at 5.0 V AC they are wonderful. > > The plates run about 305VDC and current about 20mA. > I can confirm that 801s (which oughta be similar) sound great at that operating point (300V, 20mA and 6.3V on the filaments). - -Steve ========================================================================= From: evaguido Subject: Re: [JN] 10 Tube, VT25 DC Coupled driven by 6sn7 Date: Sat, 10 Feb 2001 12:49:30 +0100 Source: Sound Digest Archive v02.n803 Guys Arent these tubes supposed to run on 7.5 V ? lowering heater voltage will decrease life expectancy...... Enjoy your sound (a little longer :-) Guido At 21:46 9-2-01 -0500, SBench@aol.com wrote: >In a message dated 01-02-09 21:28:51 EST, rconte@attglobal.net writes: > >> I just installed 2 - 10's running only 6.3 V AC Filament supply v. req. >> 7.5 and do they ever sound good, just DC coupled >> via 6SN7's, rectifier is GZ37 and outputs are NOS. >> >> Anyone use these, they are the BRIGHTEST filaments I've seen, look like >> Svetlana Triodes. >> >> The tubes GE VT25 and RCA VT25...even at 5.0 V AC they are wonderful. >> >> The plates run about 305VDC and current about 20mA. >> > >I can confirm that 801s (which oughta be similar) sound great at >that operating point (300V, 20mA and 6.3V on the filaments). > >-Steve ========================================================================= From: SBench@aol.com Subject: Re: [JN] 10 Tube, VT25 DC Coupled driven by 6sn7 Date: Sat, 10 Feb 2001 20:16:46 EST Source: Sound Digest Archive v02.n803 In a message dated 01-02-10 06:46:26 EST, EvaGuido@iaehv.nl writes: > Guys > > Arent these tubes supposed to run on 7.5 V ? > > lowering heater voltage will decrease life expectancy...... > > Enjoy your sound (a little longer :-) > Hi, DHT W-Th filaments when run starved can be regenerated to a large extent. Procedure is in RCA TT3 among other places. Note that the operating point chosen is very low with respect to the tubes capability (6 watts and only 20mA). When running close to the tubes rated capabilities, starving the filament will indeed lead to (temporarily) reduced life. With oxide coated devices, the tube cannot successfully be resuscitated so beware of using that technique on oxide devices (2A3, 300B etc). Thanks for the cautionary note. Best Regards, Steve ========================================================================= From: evaguido Subject: Re: [JN] 10 Tube, VT25 DC Coupled driven by 6sn7 Date: Sun, 11 Feb 2001 22:28:19 +0100 Source: Sound Digest Archive v02.n804 Hi all Steve wrote: >DHT W-Th filaments when run starved can be regenerated to a large >extent. Procedure is in RCA TT3 among other places. I'll give that a look >Note that the >operating point chosen is very low with respect to the tubes capability >(6 watts and only 20mA). Yes > When running close to the tubes rated >capabilities, starving the filament will indeed lead to (temporarily) reduced >life. With oxide coated devices, the tube cannot successfully be >resuscitated so beware of using that technique on oxide devices >(2A3, 300B etc). Yes, that is true, however regenerating needs extreme care as the tube may die as well, if not regnerated the right way (but what can you loose....) >Thanks for the cautionary note. thanks ! Guido >Best Regards, >Steve ========================================================================= From: Allen Wright Subject: [JN] Re: 10 turn ww pots Date: Sat, 13 Feb 1999 08:42:30 -0500 Source: Sound Digest Archive v02.n044 Various people contributed: >>>> I believe the ten-turns do not sound OK, though I did not listen to them........Crack one open and you will see very quickly why. They are made with a VERY long spirial element. Very high inductance<<< Gents, this is all opinion. Has anyone actually taken a listen? Allen (VSE) ========================================================================= From: Grover Gardner Subject: Re: [JN] Re: 10 turn ww pots Date: Sat, 13 Feb 1999 22:03:46 -0500 Source: Sound Digest Archive v02.n044 At 8:42 AM -0500 2/13/99, Allen Wright wrote: >Various people contributed: > >>>>> I believe the ten-turns do not sound OK, though I did not listen to >them........Crack one open and you will see very quickly why. They are made >with a VERY long spirial element. Very high inductance<<< > >Gents, this is all opinion. Has anyone actually taken a listen? > >Allen (VSE) 10 turn pots can be very noisy and unsatisfactory sonically, if used directly in the input path. Grover Gardner groverg@postoffice.att.net ========================================================================= From: "PEARL Cust Serv" Subject: Re: [JN] Re: 10 turn ww pots Date: Sat, 13 Feb 1999 22:36:57 -0700 Source: Sound Digest Archive v02.n044 >From: Grover Gardner >To: Allen Wright , JoeNet >Subject: Re: [JN] Re: 10 turn ww pots >Date: Sat, Feb 13, 1999, 8:03 PM > > At 8:42 AM -0500 2/13/99, Allen Wright wrote: >>Various people contributed: >> >>>>>> I believe the ten-turns do not sound OK, though I did not listen to >>them........Crack one open and you will see very quickly why. They are made >>with a VERY long spirial element. Very high inductance<<< >> >>Gents, this is all opinion. Has anyone actually taken a listen? >> >>Allen (VSE) > > 10 turn pots can be very noisy and unsatisfactory sonically, if used > directly in the input path. > > Grover Gardner > groverg@postoffice.att.net - -------------------- I was hoping against hope. Steppers are SUCH a PITA!! Bill - PEARL ========================================================================= From: evaguido Subject: Re: [JN] Re: 10 turn ww pots Date: Sun, 14 Feb 1999 22:46:41 +0100 Source: Sound Digest Archive v02.n044 At 08:42 13-2-99 -0500, Allen Wright wrote: >Various people contributed: > >>>>> I believe the ten-turns do not sound OK, though I did not listen to >them........Crack one open and you will see very quickly why. They are made >with a VERY long spirial element. Very high inductance<<< > >Gents, this is all opinion. Has anyone actually taken a listen? I suppose... As I wrote, the series inductance might be a burden, but it depends on the loading impedance The proof is in the eating of the pudding. I guess at least I have to buy a pair Which brand is reccomended ? Guido >Allen (VSE) > > ========================================================================= From: Torsten.Loesch@enhar-ha.nthames.nhs.uk Subject: Re: [JN] Re: 10 turn ww pots Date: 15 Feb 1999 11:30:35 +0000 Source: Sound Digest Archive v02.n044 Hi there, > >>>> I believe the ten-turns do not sound OK, though I did not listen to > them........Crack one open and you will see very quickly why. They are made > with a VERY long spirial element. Very high inductance<<< > > Gents, this is all opinion. Has anyone actually taken a listen? I did. While still doing solid Stae. I did not like the sound much. Though due to low capacitances there was not much rolloff.... I still think that the only way is a stepped (ladder) attenuator. Cermet pots are close but wear out quickly and often have tracking problems.... Later Thorsten ========================================================================= From: SBench@aol.com Subject: [JN] 10W SE No R No C Amp Date: Sun, 24 Dec 2000 00:56:12 EST Source: Sound Digest Archive v02.n769 Hi All, Finally had a bit of time to update my web page. I put up an 845 amp providing about 10 watts using only tubes, transformers and inductors. Driver stage is differential 6DJ8 (push pull class A driver) driving SE 845. Interestingly, provides some insight into how power systems affect the sound quality! During development I was able to find topologies producing graininess (traced to limited slew rate at HF, even though frequency response MEASURED OK) and classic old style "distorted tube" sound (related to signal frequency ripple). Direct access via http://members.aol.com/sbench/norc845.html or by the front door at http://members.aol.com/sbench101 Best of seasons greetings to all. Steve ========================================================================= From: Grover Gardner Subject: Re: [JN] 10Y (VT-25) vs 801A Date: Thu, 12 Aug 1999 11:38:23 -0400 Source: Sound Digest Archive v02.n240 I have been exploring this myself. I would assume the 801 is built to allow more grid current. I know the plate and grid structures are different, the 801 having a boxer, deeper plate. I haven't yet been able to compare the sound of the two. jsuen wrote: > > Hello, > > I would like to know if there is any significant difference between 10Y > and 801A apart from higher voltage and power ratings of the latter. - -- Grover Gardner groverg@postoffice.att.net ========================================================================= From: jsuen Subject: [JN] 10Y (VT-25) vs 801A Date: Thu, 12 Aug 1999 19:25:33 +0800 Source: Sound Digest Archive v02.n240 Hello, I would like to know if there is any significant difference between 10Y and 801A apart from higher voltage and power ratings of the latter. ========================================================================= From: Carter Hendricks Subject: [JN] 112A/12A Date: Wed, 28 Mar 2001 22:48:01 -0600 Source: Sound Digest Archive v02.n847 Does anyone have 4 of these new/used for purchase or trade??? --Carter ========================================================================= From: "Danielak, Robert M" Subject: [JN] RE: 112 pre with battery filaments Date: Wed, 06 Dec 2000 17:20:57 -0500 Source: Sound Digest Archive v02.n754 hi folks, where shall i start? ok Q1: should you charge while playing audio? probably not. as the bear mentioned below, it sorta defeats the purpose of battery filaments. now nicads are known for their very low impedance, and some folks go on to suggest that they make good "ripple-filters". but they do have significant impedance at higher frequencies. the go inductive starting above 100Hz to 1kHz. Q2: should you use ni-cads or lead-acid? memory effect is almost a joke in the industry, these days. most battery engineers consider it an "urban-legend". most capacity loss in nicad packs is done by heavy discharge to very low states of charge - i.e. running the batteries flat. in a series pack of 4 or six cells, oftentimes one or more of these cells (weakest) are forced into reversal (negative voltage). this causes premature degradation which some folks attribute to "memory-effect". overcharging has a similar effect... now for this application, what is the best choice? 5V @ 0.25A means that you need 4 ni-cads in series (~4.8V). but the voltage profile if fairly flat. a D-cell is anywhere between 4 to 5 Ah. so theoretically, you can get 16-20 hours out of them. self-discharge is quite high for ni-cads though. you might want to keep them on a trickle-charge once they're topped up. C/50, or about 100mA is a good rate. the charger could be as simple as a constant current source switchable between a *fast* rate and a *trickle* rate, or just a single *low* rate for overnight (8-10 hour charging). you could expect that most of the time, you won't discharge to zero capacity, so a C/20 rate might be a good compromise. sealed-lead-acid (SLA) is a fine option, too. they won't give you as many cycles as nicad. but they are a little easier to charge. you can build a simple float charger for them using a dc power supply and a resistor. they are bulki er than nicads, but we're talking tubes, not cell-phones. 3 in series will give you 6V or so. paralleling cells with either of these battery types (especially nicad) is not recommended. if you need more capacity, get a bigger cell. a separate charger circuit is recommended for each battery. the circuits should be fairly simple, and easy to replicate. we're not talking about more than 1A, so a simple LM317 current source should be sufficient. 3. switch network i'd recommend a spdt (or DPDT if you want to isolate the grounds, too) for each battery/filament. in one position you connect the battery to the filaments, in the other position to the charger. if you are using cathode bias, i suppose you need a DPDT switch. if you need any detailed help, just let me know... hth, bob.d. > ---------- > From: Bj> řrn Aaholm[SMTP:bjorn@vt52.com] > Sent: Wednesday, December 06, 2000 3:19 PM > To: Joe List > Subject: SV: [JN] Date: Tue, 5 Dec 2000 18:57:09 -0500 > > Phil Sieg: > > > > Joes, > > > > I have the kernel of an idea bubbling in my bonnet and have some questions > > for those who have gone before. I am working on a design for a phono and > > line preamp that uses CX-112As in each stage. The stages will be > > IT-coupled > > (Sakuma-style, see his 12A/12A/12A/12A/50 phono pre/power amp design at > > Direct Heating for the general concept). > > Mighty interesting... > > > > > The 112As seem a good candidate for battery filament supplies. > > Yes, it indeed does, and this is nothing new. It was designed for battery > operation. > > > > And here > > lies my question. I want to use rechargeable NiCad battery packs in > > parallel with switching to recharge as needed (I hope I'm being > > clear). I've > > read Jim de Kort's excellent treatment of the subject on his site (and > > that's a way cool thing you are doing, Jim) but need a little > > more detail to > > implement.> > > I'm slightly involved in this project and have myself a UX-226 linestage > with battery operated filaments. Jim and I have had a lot of conversation > about how to charge this babies. Now, I don't quite see why you would want > to use NiCads. They have a most annoying memory effect. Unless you want to > keep your tubes on until the batteries are virtually drained every time you > will not have a relaxed relationship with these batteries for long. They > WILL annoy you... Use lead batteries - these may be more expensive, but they > last much longer and are much easier to use. If batteries in series are > needed for an application, parallelling them when charging is definately the > best and easiest option for a good recharge. > > > > I will use the standard power transformer/valve rectifier for the > > B+. But I > > would like to design a battery-based supply that recharges while > > in use. So > > I'm looking for help and input from those who have implemented > > these things. > > The 12A has 5V, 0.25A filaments. > > As I said, I have done this with my 26's. No problems so far AT all. I use 2 > ea 2V 8Ah lead cells in parallel per filament (with drop resistors of > course). I wouldn't want to charge the supply while in use - you loose > almost all the benefits of the battery approach... > > regards, > Bjřrn Aaholm > > http://listen.to/aaholm (Read about my UX-226 linestage here if you want to > know more) > > ========================================================================= From: "Phil Sieg" Subject: Re: [JN] RE: 112 pre with battery filaments Date: Wed, 6 Dec 2000 18:50:50 -0500 Source: Sound Digest Archive v02.n754 Bjorn, Bob: many thanks for your detailed replies. Did a little more research today (and talked at length with a local DIY friend whose an electronics instructor at the local Tech Institute). Seems lead acid is the way to go. Here's the current plan (no pun intended). I will use 6V rechargeable lead-acid batteries, one per tube. The positive leg will be fitted with a dropping resistor; the negative with a 120VAC DPDT relay that will be activated when the rectifier filament supply is turned on After greater perusal of Jim's site (and increasing appreciation for what he's doing ), I plan to build a charger per channel that put out 18V with the batteries in series. It will be switchable separately from the main PS. The batteries I'm looking at are rated for 1.3Ah for 20 Hr, which means at a draw of 250 mA, they should last a long time. A *long* listening session for me is 6-7 hours, and that's only reached usually when we have our monthly DIY get together. So I can't see the need for parallel batteries and a switching supply. So feasible/ Phil - ----- Original Message ----- From: "Danielak, Robert M" To: "Joe List" Sent: Wednesday, 06 December, 2000 17.20 Subject: [JN] RE: 112 pre with battery filaments > hi folks, > > where shall i start? > > ok > > Q1: should you charge while playing audio? > > probably not. > as the bear mentioned below, it sorta defeats the purpose of > battery filaments. > > now nicads are known for their very low impedance, and some > folks go on to suggest that they make good "ripple-filters". > > but they do have significant impedance at higher frequencies. > the go inductive starting above 100Hz to 1kHz. > > Q2: should you use ni-cads or lead-acid? > > memory effect is almost a joke in the industry, these days. > most battery engineers consider it an "urban-legend". > > most capacity loss in nicad packs is done by heavy discharge > to very low states of charge - i.e. running the batteries flat. > > in a series pack of 4 or six cells, oftentimes one or more of these cells (weakest) are forced into reversal (negative voltage). > this causes premature degradation which some folks attribute to "memory-effect". > > overcharging has a similar effect... > > now for this application, what is the best choice? > > 5V @ 0.25A means that you need 4 ni-cads in series (~4.8V). > but the voltage profile if fairly flat. > > a D-cell is anywhere between 4 to 5 Ah. > so theoretically, you can get 16-20 hours out of them. > > self-discharge is quite high for ni-cads though. > > you might want to keep them on a trickle-charge once they're > topped up. C/50, or about 100mA is a good rate. > > the charger could be as simple as a constant current source > switchable between a *fast* rate and a *trickle* rate, > or just a single *low* rate for overnight (8-10 hour charging). > > you could expect that most of the time, you won't discharge to > zero capacity, so a C/20 rate might be a good compromise. > > sealed-lead-acid (SLA) is a fine option, too. > they won't give you as many cycles as nicad. but they are a little easier to charge. > you can build a simple float charger for them using a dc power supply and a resistor. they are bulkier than nicads, but we're talking > tubes, not cell-phones. > 3 in series will give you 6V or so. > > paralleling cells with either of these battery types (especially nicad) is not recommended. > if you need more capacity, get a bigger cell. > > a separate charger circuit is recommended for each battery. > > the circuits should be fairly simple, and easy to replicate. > we're not talking about more than 1A, so a simple LM317 current > source should be sufficient. > > 3. switch network > > i'd recommend a spdt (or DPDT if you want to isolate the grounds, too) > for each battery/filament. in one position you connect the battery > to the filaments, in the other position to the charger. > > if you are using cathode bias, i suppose you need a DPDT switch. > > if you need any detailed help, just let me know... > > hth, > > bob.d. > > > ---------- > > From: Bj> řrn Aaholm[SMTP:bjorn@vt52.com] > > Sent: Wednesday, December 06, 2000 3:19 PM > > To: Joe List > > Subject: SV: [JN] Date: Tue, 5 Dec 2000 18:57:09 -0500 > > > > Phil Sieg: > > > > > > Joes, > > > > > > I have the kernel of an idea bubbling in my bonnet and have some questions > > > for those who have gone before. I am working on a design for a phono and > > > line preamp that uses CX-112As in each stage. The stages will be > > > IT-coupled > > > (Sakuma-style, see his 12A/12A/12A/12A/50 phono pre/power amp design at > > > Direct Heating for the general concept). > > > > Mighty interesting... > > > > > > > > > The 112As seem a good candidate for battery filament supplies. > > > > Yes, it indeed does, and this is nothing new. It was designed for battery > > operation. > > > > > > > And here > > > lies my question. I want to use rechargeable NiCad battery packs in > > > parallel with switching to recharge as needed (I hope I'm being > > > clear). I've > > > read Jim de Kort's excellent treatment of the subject on his site (and > > > that's a way cool thing you are doing, Jim) but need a little > > > more detail to > > > implement.> > > > > I'm slightly involved in this project and have myself a UX-226 linestage > > with battery operated filaments. Jim and I have had a lot of conversation > > about how to charge this babies. Now, I don't quite see why you would want > > to use NiCads. They have a most annoying memory effect. Unless you want to > > keep your tubes on until the batteries are virtually drained every time you > > will not have a relaxed relationship with these batteries for long. They > > WILL annoy you... Use lead batteries - these may be more expensive, but they > > last much longer and are much easier to use. If batteries in series are > > needed for an application, parallelling them when charging is definately the > > best and easiest option for a good recharge. > > > > > > > I will use the standard power transformer/valve rectifier for the > > > B+. But I > > > would like to design a battery-based supply that recharges while > > > in use. So > > > I'm looking for help and input from those who have implemented > > > these things. > > > The 12A has 5V, 0.25A filaments. > > > > As I said, I have done this with my 26's. No problems so far AT all. I use 2 > > ea 2V 8Ah lead cells in parallel per filament (with drop resistors of > > course). I wouldn't want to charge the supply while in use - you loose > > almost all the benefits of the battery approach... > > > > regards, > > Bjřrn Aaholm > > > > http://listen.to/aaholm (Read about my UX-226 linestage here if you want to > > know more) > > > > > ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] RE: 112 pre with battery filaments Date: Wed, 06 Dec 2000 19:07:33 -0500 Source: Sound Digest Archive v02.n754 minor correction phil: the rating of 1.3AH @ 20hours is simply describing how they measured the capacity (they used a C/20 rate). they specify the 20-hour rate because it gives them a better #. if you used a 2 hour rate (C/2) you would wind up with less capacity (because of voltage performance). so you have to stick with the 1.3AH number as a starting point. this means that you will be able to operate for 1.3AH / 0.25A = 5.2 hours, maximum. in other words, you're using more like a c/5 discharge rate. so the capacity will be a little less, and you'll get less run-time. probably no more than 5 hours. and when they get near flat, they will drop like a rock (and potentially cause degradation). if you use a bigger battery, you will get the potential for longer run-time, and you'll be going easier on the cells during the one or two hour sessions. this means you will get more cycles out of them. also, unless you have a compelling reason to charge the packs in series, i'd suggest doing a 6V char ger per battery. it's much easier to manage if there are slight differences from battery to battery. in series, you are forcing the same charge into each battery. if one reaches ful l charge first, it will be overcharged, while the others catch up. this will shorten cycle life... a separate charger, with proper charge termination can extend the life of the batteries, significant ly. you should be able to get 500 full cycles from a modern battery. more if you treat them well (no overcharge, overdischarge/reversal). less if you abuse them. good luck, bob.d. ps: go for the battery B+ supply, too!!!! > ---------- > From: Phil Sieg[SMTP:psieg@nxs.net] > Sent: Wednesday, December 06, 2000 6:50 PM > To: Danielak, Robert M; Joe List > Subject: Re: [JN] RE: 112 pre with battery filaments > > Bjorn, Bob: > > many thanks for your detailed replies. Did a little more research today > (and talked at length with a local DIY friend whose an electronics > instructor at the local Tech Institute). Seems lead acid is the way to go. > > Here's the current plan (no pun intended). I will use 6V rechargeable > lead-acid batteries, one per tube. The positive leg will be fitted with a > dropping resistor; the negative with a 120VAC DPDT relay that will be > activated when the rectifier filament supply is turned on > > After greater perusal of Jim's site (and increasing appreciation for what > he's doing ), I plan to build a charger per channel that put out 18V with > the batteries in series. It will be switchable separately from the main PS. > The batteries I'm looking at are rated for 1.3Ah for 20 Hr, which means at a > draw of 250 mA, they should last a long time. A *long* listening session > for me is 6-7 hours, and that's only reached usually when we have our > monthly DIY get together. So I can't see the need for parallel batteries > and a switching supply. > > So feasible/ > > Phil > > > ----- Original Message ----- > From: "Danielak, Robert M" > To: "Joe List" > Sent: Wednesday, 06 December, 2000 17.20 > Subject: [JN] RE: 112 pre with battery filaments > > > > hi folks, > > > > where shall i start? > > > > ok > > > > Q1: should you charge while playing audio? > > > > probably not. > > as the bear mentioned below, it sorta defeats the purpose of > > battery filaments. > > > > now nicads are known for their very low impedance, and some > > folks go on to suggest that they make good "ripple-filters". > > > > but they do have significant impedance at higher frequencies. > > the go inductive starting above 100Hz to 1kHz. > > > > Q2: should you use ni-cads or lead-acid? > > > > memory effect is almost a joke in the industry, these days. > > most battery engineers consider it an "urban-legend". > > > > most capacity loss in nicad packs is done by heavy discharge> > > to very low states of charge - i.e. running the batteries flat. > > > > in a series pack of 4 or six cells, oftentimes one or more of these cells > (weakest) are forced into reversal (negative voltage). > > this causes premature degradation which some folks attribute to > "memory-effect". > > > > overcharging has a similar effect... > > > > now for this application, what is the best choice? > > > > 5V @ 0.25A means that you need 4 ni-cads in series (~4.8V). > > but the voltage profile if fairly flat. > > > > a D-cell is anywhere between 4 to 5 Ah. > > so theoretically, you can get 16-20 hours out of them. > > > > self-discharge is quite high for ni-cads though. > > > > you might want to keep them on a trickle-charge once they're > > topped up. C/50, or about 100mA is a good rate. > > > > the charger could be as simple as a constant current source > > switchable between a *fast* rate and a *trickle* rate, > > or just a single *low* rate for overnight (8-10 hour charging). > > > > you could expect that most of the time, you won't discharge to > > zero capacity, so a C/20 rate might be a good compromise. > > > > sealed-lead-acid (SLA) is a fine option, too. > > they won't give you as many cycles as nicad. but they are a little easier > to charge. > > you can build a simple float charger for them using a dc power supply and > a resistor. they are bulkier than nicads, but we're talking > > tubes, not cell-phones. > > 3 in series will give you 6V or so. > > > > paralleling cells with either of these battery types (especially nicad) is > not recommended. > > if you need more capacity, get a bigger cell. > > > > a separate charger circuit is recommended for each battery. > > > > the circuits should be fairly simple, and easy to replicate. > > we're not talking about more than 1A, so a simple LM317 current > > source should be sufficient. > > > > 3. switch network > > > > i'd recommend a spdt (or DPDT if you want to isolate the grounds, too) > > for each battery/filament. in one position you connect the battery > > to the filaments, in the other position to the charger. > > > > if you are using cathode bias, i suppose you need a DPDT switch. > > > > if you need any detailed help, just let me know... > > > > hth, > > > > bob.d. > > > > > ---------- > > > From: Bj> řrn Aaholm[SMTP:bjorn@vt52.com] > > > Sent: Wednesday, December 06, 2000 3:19 PM > > > To: Joe List > > > Subject: SV: [JN] Date: Tue, 5 Dec 2000 18:57:09 -0500 > > > > > > Phil Sieg: > > > > > > > > Joes, > > > > > > > > I have the kernel of an idea bubbling in my bonnet and have some > questions > > > > for those who have gone before. I am working on a design for a phono > and > > > > line preamp that uses CX-112As in each stage. The stages will be > > > > IT-coupled > > > > (Sakuma-style, see his 12A/12A/12A/12A/50 phono pre/power amp design > at > > > > Direct Heating for the general concept). > > > > > > Mighty interesting... > > > > > > > > > > > > > The 112As seem a good candidate for battery filament supplies. > > > > > > Yes, it indeed does, and this is nothing new. It was designed for > battery > > > operation. > > > > > > > > > > And here > > > > lies my question. I want to use rechargeable NiCad battery packs in > > > > parallel with switching to recharge as needed (I hope I'm being > > > > clear). I've > > > > read Jim de Kort's excellent treatment of the subject on his site (and > > > > that's a way cool thing you are doing, Jim) but need a little > > > > more detail to > > > > implement.> > > > > > > I'm slightly involved in this project and have myself a UX-226 linestage > > > with battery operated filaments. Jim and I have had a lot of > conversation > > > about how to charge this babies. Now, I don't quite see why you would > want > > > to use NiCads. They have a most annoying memory effect. Unless you want > to > > > keep your tubes on until the batteries are virtually drained every time > you > > > will not have a relaxed relationship with these batteries for long. They> > > > WILL annoy you... Use lead batteries - these may be more expensive, but > they > > > last much longer and are much easier to use. If batteries in series are > > > needed for an application, parallelling them when charging is definately > the > > > best and easiest option for a good recharge. > > > > > > > > > > I will use the standard power transformer/valve rectifier for the > > > > B+. But I > > > > would like to design a battery-based supply that recharges while > > > > in use. So > > > > I'm looking for help and input from those who have implemented > > > > these things. > > > > The 12A has 5V, 0.25A filaments. > > > > > > As I said, I have done this with my 26's. No problems so far AT all. I > use 2 > > > ea 2V 8Ah lead cells in parallel per filament (with drop resistors of > > > course). I wouldn't want to charge the supply while in use - you loose > > > almost all the benefits of the battery approach... > > > > > > regards, > > > Bjřrn Aaholm > > > > > > http://listen.to/aaholm (Read about my UX-226 linestage here if you want > to > > > know more) > > > > > > > > > > ========================================================================= From: "Phil Sieg" Subject: Re: [JN] RE: 112 pre with battery filaments Date: Wed, 6 Dec 2000 20:05:26 -0500 Source: Sound Digest Archive v02.n754 Bob, Thanks for the corrections. Panasonic has a lead-acid battery rated at 6.5Ah for 20 hrs. At 250 mA, I calculate nearly 24 hrs on that one. WRT the charger, if I can construct a charger for each channel that can feed 6V to each battery in parallel with the ability to provide at least 2A of current draw, won't that work as well as separate chargers? As far as battery B+ goes, let me get the SO used to battery filament supplies ;-). The idea of 25 12V batteries in series for each channel [3 amplifiers per side using 2 x 45 (woofer); 1 x 45 (mid); 1 x 71A (tweet)], plus the preamp is a hard sell to a spouse who has always given me free reign in the audio arena. Phil ----- Original Message ----- From: "Danielak, Robert M" To: "Joe List" Sent: Wednesday, 06 December, 2000 19.07 Subject: RE: [JN] RE: 112 pre with battery filaments > minor correction phil: > > the rating of 1.3AH @ 20hours is simply describing how they measured > the capacity (they used a C/20 rate). > > they specify the 20-hour rate because it gives them a better #. > > if you used a 2 hour rate (C/2) you would wind up with less capacity > (because of voltage performance). > > so you have to stick with the 1.3AH number as a starting point. > > this means that you will be able to operate for 1.3AH / 0.25A = 5.2 hours, maximum. > > in other words, you're using more like a c/5 discharge rate. > so the capacity will be a little less, and you'll get less run-time. > > probably no more than 5 hours. > and when they get near flat, they will drop like a rock > (and potentially cause degradation). > > if you use a bigger battery, you will get the potential for longer > run-time, and you'll be going easier on the cells during the one > or two hour sessions. this means you will get more cycles out of them. > > also, unless you have a compelling reason to charge the packs in series, i'd suggest doing a 6V charger per battery. > > it's much easier to manage if there are slight differences from > battery to battery. in series, you are forcing the same charge into each battery. if one reaches full charge first, it will be overcharged, while the others catch up. this will shorten cycle life... > > a separate charger, with proper charge termination can extend the life of the batteries, significantly. > > you should be able to get 500 full cycles from a modern battery. > more if you treat them well (no overcharge, overdischarge/reversal). > less if you abuse them. > > good luck, > > bob.d. > > ps: go for the battery B+ supply, too!!!! > > ---------- > > From: Phil Sieg[SMTP:psieg@nxs.net] > > Sent: Wednesday, December 06, 2000 6:50 PM > > To: Danielak, Robert M; Joe List > > Subject: Re: [JN] RE: 112 pre with battery filaments > > > > Bjorn, Bob: > > > > many thanks for your detailed replies. Did a little more research today > > (and talked at length with a local DIY friend whose an electronics > > instructor at the local Tech Institute). Seems lead acid is the way to go. > > > > Here's the current plan (no pun intended). I will use 6V rechargeable > > lead-acid batteries, one per tube. The positive leg will be fitted with a > > dropping resistor; the negative with a 120VAC DPDT relay that will be > > activated when the rectifier filament supply is turned on > > > > After greater perusal of Jim's site (and increasing appreciation for what > > he's doing ), I plan to build a charger per channel that put out 18V with > > the batteries in series. It will be switchable separately from the main PS. > > The batteries I'm looking at are rated for 1.3Ah for 20 Hr, which means at a > > draw of 250 mA, they should last a long time. A *long* listening session > > for me is 6-7 hours, and that's only reached usually when we have our > > monthly DIY get together. So I can't see the need for parallel batteries > > and a switching supply. > > > > So feasible/ > > > > Phil > > > > > > ----- Original Message ----- > > From: "Danielak, Robert M" > > To: "Joe List" > > Sent: Wednesday, 06 December, 2000 17.20 > > Subject: [JN] RE: 112 pre with battery filaments > > > > > > > hi folks, > > > > > > where shall i start? > > > > > > ok > > > > > > Q1: should you charge while playing audio? > > > > > > probably not. > > > as the bear mentioned below, it sorta defeats the purpose of > > > battery filaments. > > > > > > now nicads are known for their very low impedance, and some > > > folks go on to suggest that they make good "ripple-filters". > > > > > > but they do have significant impedance at higher frequencies. > > > the go inductive starting above 100Hz to 1kHz. > > > > > > Q2: should you use ni-cads or lead-acid? > > > > > > memory effect is almost a joke in the industry, these days. > > > most battery engineers consider it an "urban-legend". > > > > > > most capacity loss in nicad packs is done by heavy discharge> > > > to very low states of charge - i.e. running the batteries flat. > > > > > > in a series pack of 4 or six cells, oftentimes one or more of these cells > > (weakest) are forced into reversal (negative voltage). > > > this causes premature degradation which some folks attribute to > > "memory-effect". > > > > > > overcharging has a similar effect... > > > > > > now for this application, what is the best choice? > > > > > > 5V @ 0.25A means that you need 4 ni-cads in series (~4.8V). > > > but the voltage profile if fairly flat. > > > > > > a D-cell is anywhere between 4 to 5 Ah. > > > so theoretically, you can get 16-20 hours out of them. > > > > > > self-discharge is quite high for ni-cads though. > > > > > > you might want to keep them on a trickle-charge once they're > > > topped up. C/50, or about 100mA is a good rate. > > > > > > the charger could be as simple as a constant current source > > > switchable between a *fast* rate and a *trickle* rate, > > > or just a single *low* rate for overnight (8-10 hour charging). > > > > > > you could expect that most of the time, you won't discharge to > > > zero capacity, so a C/20 rate might be a good compromise. > > > > > > sealed-lead-acid (SLA) is a fine option, too. > > > they won't give you as many cycles as nicad. but they are a little easier > > to charge. > > > you can build a simple float charger for them using a dc power supply and > > a resistor. they are bulkier than nicads, but we're talking > > > tubes, not cell-phones. > > > 3 in series will give you 6V or so. > > > > > > paralleling cells with either of these battery types (especially nicad) is > > not recommended. > > > if you need more capacity, get a bigger cell. > > > > > > a separate charger circuit is recommended for each battery. > > > > > > the circuits should be fairly simple, and easy to replicate. > > > we're not talking about more than 1A, so a simple LM317 current > > > source should be sufficient. > > > > > > 3. switch network > > > > > > i'd recommend a spdt (or DPDT if you want to isolate the grounds, too) > > > for each battery/filament. in one position you connect the battery > > > to the filaments, in the other position to the charger. > > > > > > if you are using cathode bias, i suppose you need a DPDT switch. > > > > > > if you need any detailed help, just let me know... > > > > > > hth, > > > > > > bob.d. > > > > > > > ---------- > > > > From: Bj> řrn Aaholm[SMTP:bjorn@vt52.com] > > > > Sent: Wednesday, December 06, 2000 3:19 PM > > > > To: Joe List > > > > Subject: SV: [JN] Date: Tue, 5 Dec 2000 18:57:09 -0500 > > > > > > > > Phil Sieg: > > > > > > > > > > Joes, > > > > > > > > > > I have the kernel of an idea bubbling in my bonnet and have some > > questions > > > > > for those who have gone before. I am working on a design for a phono > > and > > > > > line preamp that uses CX-112As in each stage. The stages will be > > > > > IT-coupled > > > > > (Sakuma-style, see his 12A/12A/12A/12A/50 phono pre/power amp design > > at > > > > > Direct Heating for the general concept). > > > > > > > > Mighty interesting... > > > > > > > > > > > > > > > > > The 112As seem a good candidate for battery filament supplies. > > > > > > > > Yes, it indeed does, and this is nothing new. It was designed for > > battery > > > > operation. > > > > > > > > > > > > > And here > > > > > lies my question. I want to use rechargeable NiCad battery packs in > > > > > parallel with switching to recharge as needed (I hope I'm being > > > > > clear). I've > > > > > read Jim de Kort's excellent treatment of the subject on his site (and > > > > > that's a way cool thing you are doing, Jim) but need a little > > > > > more detail to > > > > > implement.> > > > > > > > > I'm slightly involved in this project and have myself a UX-226 linestage > > > > with battery operated filaments. Jim and I have had a lot of > > conversation > > > > about how to charge this babies. Now, I don't quite see why you would > > want > > > > to use NiCads. They have a most annoying memory effect. Unless you want > > to > > > > keep your tubes on until the batteries are virtually drained every time > > you > > > > will not have a relaxed relationship with these batteries for long. They> > > > > WILL annoy you... Use lead batteries - these may be more expensive, but > > they > > > > last much longer and are much easier to use. If batteries in series are > > > > needed for an application, parallelling them when charging is definately > > the > > > > best and easiest option for a good recharge. > > > > > > > > > > > > > I will use the standard power transformer/valve rectifier for the > > > > > B+. But I > > > > > would like to design a battery-based supply that recharges while > > > > > in use. So > > > > > I'm looking for help and input from those who have implemented > > > > > these things. > > > > > The 12A has 5V, 0.25A filaments. > > > > > > > > As I said, I have done this with my 26's. No problems so far AT all. I > > use 2 > > > > ea 2V 8Ah lead cells in parallel per filament (with drop resistors of > > > > course). I wouldn't want to charge the supply while in use - you loose > > > > almost all the benefits of the battery approach... > > > > > > > > regards, > > > > Bjřrn Aaholm > > > > > > > > http://listen.to/aaholm (Read about my UX-226 linestage here if you want > > to > > > > know more) > > > > > > > > > > > > > > > > ========================================================================= From: Simon Busbridge Subject: Re: [JN] RE: 112 pre with battery filaments Date: Thu, 7 Dec 2000 07:37:30 +0000 (GMT) Source: Sound Digest Archive v02.n754 NiMH? Supposed to be as good as NiCad but without the memory effect. Never used them personally. Simon Simon Busbridge, BSc(Hons) PhD CPhys MInstP School of Engineering University of Brighton Lewes Road Moulsecoomb Brighton BN2 4GJ UNITED KINGDOM Tel: 0044 (0)1273 642542 Fax: 0044 (0)1273 642327/642301 e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] RE: 112 pre with battery filaments Date: Thu, 07 Dec 2000 10:36:08 -0500 Source: Sound Digest Archive v02.n755 > Bob, > > Thanks for the corrections. Panasonic has a lead-acid battery rated at > 6.5Ah for 20 hrs. At 250 mA, I calculate nearly 24 hrs on that one. > yes, this is more like a C/20 rate (actually C/26). so you don't really need to make adjustments to available capacity based upon discharge rate. 6.5AH / .25A = 26 hours. > WRT the charger, if I can construct a charger for each channel that can feed > 6V to each battery in parallel with the ability to provide at least 2A of > current draw, won't that work as well as separate chargers? > you really don't want to charge cells in parallel. this is because you can't guarantee that they will share equally. you can probably build a single DC supply, then use a current source circuit (like a LM317 + resistor) for each battery. this is not too bad, really. > As far as battery B+ goes, let me get the SO used to battery filament > supplies ;-). The idea of 25 12V batteries in series for each channel [3 > amplifiers per side using 2 x 45 (woofer); 1 x 45 (mid); 1 x 71A (tweet)], > plus the preamp is a hard sell to a spouse who has always given me free > reign in the audio arena. > i hear ya. just figured that if you were taking the plunge.... ;) take care, bob.d. ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] RE: 112 pre with battery filaments Date: Thu, 07 Dec 2000 10:45:58 -0500 Source: Sound Digest Archive v02.n755 NiMH are pretty expensive. besides that, they require a more complicated charger. their main benefits include a bit higher energy density (they're smaller), decent cycle-life, and they're more environmentally friendly. they are very quickly being overtaken in the market by Lithium Ion (Li Ion). i did not suggest Li Ion because the voltage is all wrong (3.7V average), and because they need special charging techniques, as well. also, any commercially available Li ion batteries contain control/safety electronics which would probably defeat the purpose (at least philosophically) of using batteeries on toobs.... bob.d. > ---------- > From: Simon Busbridge[SMTP:S.C.Busbridge@bton.ac.uk] > Sent: Thursday, December 07, 2000 2:37 AM > To: Danielak, Robert M > Cc: Joe List > Subject: Re: [JN] RE: 112 pre with battery filaments > > NiMH? Supposed to be as good as NiCad but without the memory effect. > > Never used them personally. > > Simon > > Simon Busbridge, BSc(Hons) PhD CPhys MInstP > School of Engineering > University of Brighton > Lewes Road > Moulsecoomb > Brighton BN2 4GJ > UNITED KINGDOM > > Tel: 0044 (0)1273 642542 > Fax: 0044 (0)1273 642327/642301 > e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com > > > ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] RE: 112 pre with battery filaments Date: Thu, 07 Dec 2000 15:16:10 -0500 Source: Sound Digest Archive v02.n755 > ---------- > From: Jim de Kort[SMTP:jim@vt52.com] > Sent: Thursday, December 07, 2000 2:26 PM > To: Danielak, Robert M > Cc: sound@lists.io.com > Subject: RE: [JN] RE: 112 pre with battery filaments > > Hi, > > > > Thanks for the corrections. Panasonic has a lead-acid battery rated at > > > 6.5Ah for 20 hrs. At 250 mA, I calculate nearly 24 hrs on that one. > > >yes, this is more like a C/20 rate (actually C/26). > >so you don't really need to make adjustments to available capacity > >based upon discharge rate. > > > >6.5AH / .25A = 26 hours. > jim wrote: > Yes, but it will not be giving 6V anymore and we do not live in a > theoretical world. Take about 70% of that for effective playing time. > sure. i look at it the other way around. he's already mentioned that his max. run time will be less than 8 hours. so this guarantees rather shallow discharge cycles, which SLA batteries prefer. meaning he won't have to replace the batteries in six months.... ;) actually, these batteries will probably give close to the calculated run-time, given the resistive l oading. the voltage performance issue that you are alluding to is more of a concern in constant-power application (the most common applications - feeding a dc-dc converter ...or a motor). > >you really don't want to charge cells in parallel. > >this is because you can't guarantee that they will share equally. > > This is even more so in series. I used to charge my 32 batteries (12V) on a > single lab supply. It takes a while longer to get them all charged, but in > the end they do all fill up the same. This is not to say this is a good way > of charging. Batteries suffer this way as a battery with fuller charge will > pass (full) current to charge another battery that has been drained more. > yeah. we talked about this before... individual chargers are the way to go.... ;) > Best thing to do is use a relay (dual pole, dual contacts) to switch to > it's own little charger. A 317 costs about $1, plus a few resistors and a > transisitor, in all that should cost about $5 for an entire charger. Add > $2-3 for the relay (Siemens has very nice gold-clad silver contact relays) > and you're done. Two of these will not hurt your bank account ;))) > amen... > >you can probably build a single DC supply, then use a current source > >circuit (like a LM317 + resistor) for each battery. > > Voltage source... > right you are. you can simply build a "float-charger". this would be a DC regulated supply set to about 2.2 to 2.3V per cell (6.6 to 6.9V for your 6V battery). it think 6.75V is the recommended float voltage for most manufacturers. check the temperatures on the first few charges. if the batteries are getting too hot, reduce the vo ltage a 10th... would be a good idea to try to implement current limiting of some sort in each circuit. find out the max. rate for that cell. it's probably around 2.5A. > Yes indeed, this is what I do in my chargers. One big > rectifier and capacitor and then split to 8 charger circuits. > > >just figured that if you were taking the plunge.... ;) > > There's an address in the UK (www.steatite.co.uk) that has really cheap > 12V/2Ah batteries ($6-8 each). If you live in the UK this might be a good > oppertunity. I would have done it already, but shipping (even to just > across the channel) is about 4 times that due to weight. > > > > > Regards, > > > Jim de Kort > jim@vt52.com > ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] RE: 112 pre with battery filaments Date: Thu, 07 Dec 2000 16:15:22 -0500 Source: Sound Digest Archive v02.n755 > >the voltage performance issue that you are alluding to is more > >of a concern in constant-power application (the most common applications - > >feeding a dc-dc converter...or a motor). > > A filament would qualify this description. > interesting... i would have considered it purely resistive. i'll have to think about this.... > >you can simply build a "float-charger". > > That is actually what I have. As long as the power switch is turned off, > the batteries are being charged. The supply is set to 2.3V and current > limited to C/10 by way of two resistors and a transistor. > jim is da' man! just do as he's done ;) > >check the temperatures on the first few charges. if the batteries are > >getting too hot, reduce the voltage a 10th... > > My batteries don't even get luke warm. If they are getting warm then the > current is too high and should be limited. These high currents and > temperatures limit battery life. The amp has all night to recharge, so no > hurry, why push 2A into them when 0.5A will do the job in time for the next > session. > there you go... > >would be a good idea to try to implement current limiting of some sort > >in each circuit. find out the max. rate for that cell. > > Take C/10, it's not the max specification, but it will lengthen tube life > and still recharge before the morning. See my site for a schematic using > the current limiter. > like i said, jim's da' man! take care, bob.d. ========================================================================= From: "Phil Sieg" Subject: Re: [JN] RE: 112 pre with battery filaments Date: Thu, 7 Dec 2000 16:31:49 -0500 Source: Sound Digest Archive v02.n755 Jim, Bob, Thanks again. I think the fog is beginning to clear ;-). Here's what I've come up with, based on your help. One Panasonic 6V, 6.5Ah battery for each tube. (Jim, I am in the US.) A 3-stage version of Tom Ronan's regulator. I have several and can do one per tube. This gives two stages of voltage reg and one of current reg (which is decidedly overkill, but my current preamp now has them on the filament supplies, so my only outlay will be for a few resistors). I have some Hammond filament trannies (12.6V, 2.5A). Put those in the power supply chassis - 1 per channel - rectified and filtered , with a NIWW trim pot to trim the voltage to that required at the inputs of the regulators (I'll need to drop around 5VDC). Feed the regulators from this DC supply in parallel The current reg will be set to allow the battery to draw the 6.75V at 650 MA. Add the relay at the filaments to switch between "charge" and "heat" plus a separate power switch on the charger supply in the PS chassis. Sound right? Have I missed anything? Phil - ----- Original Message ----- From: "Danielak, Robert M" To: Sent: Thursday, 07 December, 2000 15.16 Subject: RE: [JN] RE: 112 pre with battery filaments > > ---------- > > From: Jim de Kort[SMTP:jim@vt52.com] > > Sent: Thursday, December 07, 2000 2:26 PM > > To: Danielak, Robert M > > Cc: sound@lists.io.com > > Subject: RE: [JN] RE: 112 pre with battery filaments > > > > Hi, > > > > > > Thanks for the corrections. Panasonic has a lead-acid battery rated at > > > > 6.5Ah for 20 hrs. At 250 mA, I calculate nearly 24 hrs on that one. > > > > >yes, this is more like a C/20 rate (actually C/26). > > >so you don't really need to make adjustments to available capacity > > >based upon discharge rate. > > > > > >6.5AH / .25A = 26 hours. > > > jim wrote: > > > Yes, but it will not be giving 6V anymore and we do not live in a > > theoretical world. Take about 70% of that for effective playing time. > > > sure. > > i look at it the other way around. > > he's already mentioned that his max. run time will be less than 8 hours. > > so this guarantees rather shallow discharge cycles, which SLA > batteries prefer. meaning he won't have to replace the batteries in > six months.... ;) > > actually, these batteries will probably give close to the calculated run-time, given the resistive loading. > > the voltage performance issue that you are alluding to is more > of a concern in constant-power application (the most common applications - feeding a dc-dc converter...or a motor). > > > >you really don't want to charge cells in parallel. > > >this is because you can't guarantee that they will share equally. > > > > This is even more so in series. I used to charge my 32 batteries (12V) on a > > single lab supply. It takes a while longer to get them all charged, but in > > the end they do all fill up the same. This is not to say this is a good way > > of charging. Batteries suffer this way as a battery with fuller charge will > > pass (full) current to charge another battery that has been drained more. > > > yeah. > we talked about this before... > > individual chargers are the way to go.... ;) > > > Best thing to do is use a relay (dual pole, dual contacts) to switch to > > it's own little charger. A 317 costs about $1, plus a few resistors and a > > transisitor, in all that should cost about $5 for an entire charger. Add > > $2-3 for the relay (Siemens has very nice gold-clad silver contact relays) > > and you're done. Two of these will not hurt your bank account ;))) > > > amen... > > > >you can probably build a single DC supply, then use a current source > > >circuit (like a LM317 + resistor) for each battery. > > > > Voltage source... > > > right you are. > > you can simply build a "float-charger". > this would be a DC regulated supply set to about 2.2 to 2.3V per cell > (6.6 to 6.9V for your 6V battery). it think 6.75V is the recommended > float voltage for most manufacturers. > > check the temperatures on the first few charges. if the batteries are getting too hot, reduce the voltage a 10th... > > would be a good idea to try to implement current limiting of some sort > in each circuit. find out the max. rate for that cell. > > it's probably around 2.5A. > > > Yes indeed, this is what I do in my chargers. One big > > rectifier and capacitor and then split to 8 charger circuits. > > > > >just figured that if you were taking the plunge.... ;) > > > > There's an address in the UK (www.steatite.co.uk) that has really cheap > > 12V/2Ah batteries ($6-8 each). If you live in the UK this might be a good > > oppertunity. I would have done it already, but shipping (even to just > > across the channel) is about 4 times that due to weight. > > > > > > > > > > Regards, > > > > > > Jim de Kort > > jim@vt52.com > > > ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] RE: 112 pre with battery filaments Date: Thu, 07 Dec 2000 17:40:32 -0500 Source: Sound Digest Archive v02.n755 depends upon the manufacturer of the cells/packs. the ubiquitous 18650 cells themselves (made by sony, sanyo, etc) have built-in PTC devices and pressure switches to protect them from overcharge and over discharge. some battery packs have external protection and cell-level charge-management circuits. > ---------- > From: Aigner Josef, Dr.[SMTP:j.aigner@igk.co.at] > Sent: Thursday, December 07, 2000 5:11 PM > To: Danielak, Robert M; Joenet (E-Mail) > Subject: AW: [JN] RE: 112 pre with battery filaments > > What kind of safety device ? > > Josef > > > -----Urspr> üngliche Nachricht----- > > Von: Danielak, Robert M [SMTP:robert.m.danielak@lmco.com] > > Gesendet am: Donnerstag, 07. Dezember 2000 16:46 > > An: Joe List > > Betreff: RE: [JN] RE: 112 pre with battery filaments > > > > NiMH are pretty expensive. > > besides that, they require a more complicated charger. > > > > their main benefits include a bit higher energy density > > (they're smaller), decent cycle-life, and they're more environmentally > > friendly. > > > > they are very quickly being overtaken in the market by > > Lithium Ion (Li Ion). > > > > i did not suggest Li Ion because the voltage is all wrong > > (3.7V average), and because they need special charging techniques, > > as well. > > > > also, any commercially available Li ion batteries contain > > control/safety electronics which would probably defeat the purpose > > (at least philosophically) of using batteeries on toobs.... > > > > bob.d. > > > ---------- > > > From: Simon Busbridge[SMTP:S.C.Busbridge@bton.ac.uk] > > > Sent: Thursday, December 07, 2000 2:37 AM > > > To: Danielak, Robert M > > > Cc: Joe List > > > Subject: Re: [JN] RE: 112 pre with battery filaments > > > > > > NiMH? Supposed to be as good as NiCad but without the memory effect. > > > > > > Never used them personally. > > > > > > Simon > > > > > > Simon Busbridge, BSc(Hons) PhD CPhys MInstP > > > School of Engineering > > > University of Brighton > > > Lewes Road > > > Moulsecoomb > > > Brighton BN2 4GJ > > > UNITED KINGDOM > > > > > > Tel: 0044 (0)1273 642542 > > > Fax: 0044 (0)1273 642327/642301 > > > e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com > > > > > > > > > > ========================================================================= From: StepHydro@aol.com Subject: [JN] 1200VDC plate on an OPT Date: Wed, 17 Mar 1999 14:13:47 EST Source: Sound Digest Archive v02.n078 JN denizens, I have a friend who is building a pair of PP 845 monoblocs. He wants to run 1200VDC on the plates. His transformers are 80 Watt Peerless. Does anyone know if Peerless used insualtion on the OPTs that would withstand that voltage? Cheers/Carron ========================================================================= From: Allen Wright Subject: [JN] 120dB ESLs Date: Thu, 29 Mar 2001 04:42:02 -0500 Source: Sound Digest Archive v02.n847 dnb said "Please tell us more!" The brand is "monitor DB" and they will be shown at this years Amsterdam AES by Beyerdynamic (the headphone people) as a potential theater speaker! It's approx 170 cm high by 50cm wide, a single curved panel like a Martin Logan. It is not vertically segmented. Looks good but not slick like a ML. The associated subwoofer is a matching box of the same frontal size, but perhaps 70cm deep, using 4 ~10" cone woofers in a sealed box. It is bi-amped, electronically crossing at 115Hz. The designer is a small commercial speaker manufacturer - doing a range of box speakers that he sells only in Germany through a dealer network. He does no advertising, doean't exhibit at trade shows - seems not to need to. No website! What I heard was no lashed up prototype - but a full for sale product. Price - DM35,000 (approx $US15,000) and comparing them to anything else hi-end hifi they are way underpriced. I asked what happens when they are overdriven - what's the failure mode? He said "Don't know - it's never happened. At some technical university they put in 1200 watts and the measured distortion was lower for the speaker than the amp..." Allen (VSE) ========================================================================= From: "J. Gordon Rankin" Subject: Re: [JN] 120dB ESLs Date: Thu, 29 Mar 01 07:55:16 -0500 Source: Sound Digest Archive v02.n847 Allen, So is this 120dB per watt or capable of 120dB? Do they have a website? Gordon =====> Wavelength Audio, ltd. <===== mailto:waudio@cinti.net mailto:wavelength@fuse.net http://www.WavelengthAudio.com ph.fx. 513-271-4186 USA ========================================================================= From: David Barnett Subject: Re: [JN] 120dB ESLs Date: Thu, 29 Mar 2001 11:03:42 -0600 Source: Sound Digest Archive v02.n848 On Thu, 29 Mar 2001 07:55:16 -0500, "J. Gordon Rankin" wrote: >So is this 120dB per watt or capable of 120dB? I believe it was previously stated that the sensitivity is ~92dB/1W/1M. - --dnb ========================================================================= From: evaguido Subject: Re: [JN] 120dB ESLs Date: Thu, 29 Mar 2001 20:47:45 +0200 Source: Sound Digest Archive v02.n848 Hi The perception "per watt" is not correct It suggests that you get twice the amount of dBs when increasing the power each watt.... Guido At 11:03 29-3-01 -0600, David Barnett wrote: >On Thu, 29 Mar 2001 07:55:16 -0500, "J. Gordon Rankin" > wrote: > >>So is this 120dB per watt or capable of 120dB? > >I believe it was previously stated that the sensitivity is >~92dB/1W/1M. > >--dnb ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 127 & 50 Date: Sun, 9 Jan 2000 19:50:08 EST Source: Sound Digest Archive v02.n393 In a message dated 1/9/00 4:58:43 PM US Mountain Standard Time, mikubala@swissonline.ch writes: > Is it normal that black gents of Texas speak Russian and have shiny black shoes??? Texas and normal. We went to Texas to visit our son and his wife for Thanksgiving. Driving home, there was an accident on the freeway many miles ahead. All the pickups and big American sedans, us included, immediately went across the divider to the frontage road and kept going fast. The minivans and SUVs stayed in line to wait (city people). It looked like a fancy military parade maneuver :) There are lots of people in Texas who listen to music on homebrew amps and speakers :) Happy Ears! Al B^} ========================================================================= From: Grover Gardner Subject: Re: [JN] 127 & 50 Date: Sun, 9 Jan 2000 20:29:25 -0500 Source: Sound Digest Archive v02.n393 - --============_-1264653574==_ma============ Content-Type: text/plain; charset="us-ascii" ; format="flowed" At 1:07 AM +0100 1/10/01, Miroslav Kubala wrote: >Hallo > >Saturday afternoon I was lucky to get >1 globe Philco 50 triode , looking brand new and a smaller >similar looking with blue!! glas " Arturus" brandet 127 tube..... >I have one more 50 in my collection but - helas ! - not the >same shape. >What coud I build with this tubes ??? >Is an other 127 hard to find ( as driver for the 50) ??? >A nice mono amp???? The 50 is limited to 10K grid impedance. You need to use either very low-impedance driver suitable to drive 10K load, or preferably either a direct-coupled circuit or interstage transformer for the 50. A single, plate-loaded 27 won't be much good, I think. 27s are fairly plentiful here, but the older, globe and mesh-plate types are generally well-used and finding a quiet, well-matched pair is difficult. Neat tube, though. - ------- Grover Gardner groverg@postoffice.att.net - --============_-1264653574==_ma============ Content-Type: text/enriched; charset="us-ascii" At 1:07 AM +0100 1/10/01, Miroslav Kubala wrote: ArialHallo Saturday afternoon I was lucky to get 1 globe Philco 50 triode , looking brand new and a smaller similar looking with blue!! glas " Arturus" brandet 127 tube..... I have one more 50 in my collection but - helas ! - not the same shape. What coud I build with this tubes ??? Is an other 127 hard to find ( as driver for the 50) ??? A nice mono amp???? Arial The 50 is limited to 10K grid impedance. You need to use either very low-impedance driver suitable to drive 10K load, or preferably either a direct-coupled circuit or interstage transformer for the 50. A single, plate-loaded 27 won't be much good, I think. 27s are fairly plentiful here, but the older, globe and mesh-plate types are generally well-used and finding a quiet, well-matched pair is difficult. Neat tube, though. - ------- Grover Gardner groverg@postoffice.att.net - --============_-1264653574==_ma============-- ========================================================================= From: "Miroslav Kubala" Subject: [JN] 127 & 50 Date: Wed, 10 Jan 2001 01:07:25 +0100 Source: Sound Digest Archive v02.n393 This is a multi-part message in MIME format. - ------=_NextPart_000_003A_01C07AA1.B1C9F560 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hallo Saturday afternoon I was lucky to get 1 globe Philco 50 triode , looking brand new and a smaller similar looking with blue!! glas " Arturus" brandet 127 tube..... I have one more 50 in my collection but - helas ! - not the same shape. What coud I build with this tubes ??? Is an other 127 hard to find ( as driver for the 50) ??? A nice mono amp???? Also the new drivers from Supravox are here , named 2000,send in a wooden box with a HAWWWY alnico magnet,phase plug and a new suspension I have never seen bevore. They sound already wunderfull on a open baffle !!! They also fit in a big horn I got from Holland - there used to be a Lowther driver .................R.I.P.!!!! Shall I put pics of the Supravox on my webpage??? By the way , I was saturday in Zurich to get a lesson in medical astrology!!!??? and 11.15 PM at the bar of the hotel Baur au Lac I met a black gentleman from Texas with khakkis and a wonderfull looking hat ( he said the brand is "DOCs") what he promissed to send me. Some time later & drinks more Mr.Ali told me that he is a rocket = ingenieur and spend lately some time with Mr.#1 of Russia Putin and is on his way = home. The funny thing was that again some time etc.later we both ( HE started = ) have been singing Katusa in russian in the bar of the city of$$$$$$$. Is it normal that black gents of Texas speak russian and have shiny = black shoes??? Mirko www.jurapharmacy.ch - ------=_NextPart_000_003A_01C07AA1.B1C9F560 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hallo
 
Saturday afternoon I was lucky to = get
1 globe Philco 50 triode , looking = brand new and a=20 smaller
similar looking with blue!! glas " = Arturus" brandet=20 127 tube.....
I have one more 50 in my collection but = - - helas ! -=20 not the
same shape.
What coud I build with this tubes = ???
Is an other 127 hard to find ( as = driver for the=20 50) ???
A nice mono amp????
 
Also the new drivers from Supravox are = here , named=20 2000,send in a
wooden box with a HAWWWY alnico = magnet,phase plug=20 and a new
suspension I have never seen = bevore.
They sound already wunderfull on a open = baffle=20 !!!
They also fit in a big horn I got from = Holland -=20 there used to be a
Lowther driver=20 .................R.I.P.!!!!
Shall I put pics of the Supravox on my=20 webpage???
 
By the way , I was saturday in Zurich = to get a=20 lesson in
medical astrology!!!??? and 11.15 PM at = the bar of=20 the hotel
Baur au Lac I met a black gentleman = from Texas with=20 khakkis
and a wonderfull looking hat ( he said = the brand is=20 "DOCs") what he
promissed to send me.
Some time later & drinks more = Mr.Ali told me=20 that he is a rocket ingenieur
and spend lately some time with Mr.#1 = of Russia=20 Putin and is on his way home.
The funny thing was that again some = time etc.later=20 we both ( HE started )
have been singing Katusa in russian in = the bar of=20 the city of$$$$$$$.
Is it normal that black gents of Texas = speak=20 russian and have shiny black shoes???
 
Mirko
 
www.jurapharmacy.ch
 
 
- ------=_NextPart_000_003A_01C07AA1.B1C9F560-- ========================================================================= From: "Joe" Subject: Re: [JN] 127 & 50 & docs Date: Sun, 9 Jan 2000 22:16:57 -0800 Source: Sound Digest Archive v02.n393 Well regardless of shoes or hat, the guy sounds like an arms dealer who sells clothing as a sideline..;-) Maybe a Joe-List member should always try to accompany Mirko on these late night visits to Zurich Bars. ;-) Joe Pledger - ----- Original Message ----- From: David Barnett To: Sent: Sunday, January 09, 2000 8:36 PM Subject: Re: [JN] 127 & 50 & docs > On Mon, 10 Jan 2000 11:41:44 +1100, David Crittle > wrote: > > >The shiny black shoes (not the hat) are "docs", short for Doctor Martin. > > Doctor Martens. A Dane, if I remember correctly. > > --dnb > ========================================================================= From: David Barnett Subject: Re: [JN] 127 & 50 & docs Date: Sun, 09 Jan 2000 22:36:05 -0600 Source: Sound Digest Archive v02.n393 On Mon, 10 Jan 2000 11:41:44 +1100, David Crittle wrote: >The shiny black shoes (not the hat) are "docs", short for Doctor Martin. Doctor Martens. A Dane, if I remember correctly. - --dnb ========================================================================= From: David Crittle Subject: [JN] 127 & 50 & docs Date: Mon, 10 Jan 2000 11:41:44 +1100 Source: Sound Digest Archive v02.n393 >From: "Miroslav Kubala" >I met a black gentleman >from Texas with khakkis and a wonderfull looking >hat ( he said the brand is "DOCs") what he promissed to send me. Some >time later & drinks more Mr.Ali told me that he is a rocket ingenieur and >spend lately some time with Mr.#1 of Russia Putin and is on his way home. >The funny thing was that again some time etc.later we both ( HE started ) >have been singing Katusa in russian in the bar of the city of$$$$$$$. Is >it normal that black gents of Texas speak russian and have shiny black >shoes??? Mirko www.jurapharmacy.ch Dear Mirko The shiny black shoes (not the hat) are "docs", short for Doctor Martin. ========================================================================= From: Tim_Bailey@medibank.com.au Subject: [JN] Re: 12au7's vs 5687's sound-digest V2 #491 Date: Mon, 27 Mar 2000 11:48:06 +1000 Source: Sound Digest Archive v02.n497 Jim, Could I suggest that you also try 6cg7's in that circuit. Noval but a direct electrical 6SN7 equivalent! I don't think they draw that much more than a 12au7, certainly not as much as a 5687. Tim B **************************************************************** NOTICE - This message is intended only for the use of the addressee named above and may contain privileged and confidential information. If you are not the intended recipient of this message you are hereby notified that you must not disseminate, copy or take any action based upon it. If you received this message in error please notify Medibank Private Ltd immediately. Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Medibank Private Ltd. **************************************************************** ========================================================================= From: "Hugh R. Dean" Subject: [JN] 12B4 Date: Wed, 28 Feb 2001 20:31:18 +1100 Source: Sound Digest Archive v02.n820 Folks, I have been thinking about CFs. Have any of you tried the 12B4? It sports low mu (6.5) and low rp (1030R) and might be a good candidate. Any experience? Does it go best with AC or DC heaters? Thanks, Hugh Hugh R. Dean Research/Technical Director www.printedelectronics.com Melbourne AUSTRALIA ========================================================================= From: David Barnett Subject: Re: Sv: [JN] 12B4 Date: Wed, 28 Feb 2001 13:52:03 -0600 Source: Sound Digest Archive v02.n821 On Wed, 28 Feb 2001 19:06:24 +0100, Kurt Steffensen wrote: >I once used it for output tube as well. Julius Futterman used 12B4s as outputs in some of his early, direct-coupled OTL amplifiers. - --dnb ========================================================================= From: "Kurt Steffensen" Subject: Sv: [JN] 12B4 Date: Wed, 28 Feb 2001 19:06:24 +0100 Source: Sound Digest Archive v02.n821 Hugh and all. 12B4 is one of my favorite tubes from line signals to driver. And it makes a magnificent CF. ( Are you guys beginning to explore the merits of this wonderfull little circuit ? ;-) I use DC heaters , though it is probably not really necassary. Depends upon how much noise you accep t. 12B4 is a triode that does what it is told. Nothing less , nothing more. DEAD neutral ! And it is able to reproduce a clean 24 bit dynamic range..... Don't know how it will behave as an MC amp.. The electrode structure is to dramatic for such small s ignals , for my taste. But I do not doubt , that the white noise could be low. I would worry about microphonics , at such l ow levels , though. I once used it for output tube as well. Cool :-) It makes a good circlotron , Remco ;-) And by the way , it is an excellent regulator triode :-) But 6AS7 and 6336 is better. What does that YMMV means ? - - Kurt ========================================================================= From: Christian Rintelen Subject: Re: Sv: [JN] 12B4 Date: Wed, 28 Feb 2001 19:55:55 +0100 Source: Sound Digest Archive v02.n821 Kurt, > Don't know how it will behave as an MC amp.. The electrode structure is to dramatic for such small signals , for my taste. > But I do not doubt , that the white noise could be low. I would worry about microphonics , at such low levels , though. Why for heavens sake use a tube with mu 6.5 as an mc headamp?! I strongly guess the Joe asking this was joking... > And by the way , it is an excellent regulator triode :-) > But 6AS7 and 6336 is better. A 6336 makes a purdy impressive linestage, too.... fairly low Rp... ;-) (Actually, I've heard 6336 linestage. It sounded surprisingly good!) > What does that YMMV means ? Your Mileage May Vary (what a weird way to say that your experience may well be different... typical ly American, I'd say in my best Swissgerman... ;-) © ========================================================================= From: evaguido Subject: Re: Sv: [JN] 12B4 Date: Wed, 28 Feb 2001 23:41:24 +0100 Source: Sound Digest Archive v02.n821 dear all A 12b4 OTL can be found at http://www.infomaniak.ch/~bonavolt/12b4.htm regards Guido ========================================================================= From: "Bart Shepherd \(Home\)" Subject: RE: Sv: [JN] 12B4 Date: Thu, 1 Mar 2001 06:54:21 +1100 Source: Sound Digest Archive v02.n821 > Behalf Of Christian Rintelen Sent: Thursday, 1 March 2001 5:56 AM Why for heavens sake use a tube with mu 6.5 as an mc headamp?! I strongly guess the Joe asking this was joking... > I think that was me - YES, just joking! Bart ========================================================================= From: "Paul Croft" Subject: RE: Sv: [JN] 12B4 Date: Fri, 2 Mar 2001 06:22:33 -0500 Source: Sound Digest Archive v02.n824 Hi Christian, Yes, it is weirdly American. Due to the government's truth in advertising laws here, car manufactures generally qualify their mileage claims with the phrase "Your mileage may vary", as some of us have a heavier foot on the gas pedal than others. On this side of the pond, it has become an easy acronym for internet use. Disgustin', ain't it? (Hmm, didn't Daffy Duck say that? (g)) Cheers, Paul > -----Original Message----- > From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On > Behalf Of Christian Rintelen > Sent: Wednesday, February 28, 2001 1:56 PM > To: Joelist > Subject: Re: Sv: [JN] 12B4 > > > Kurt, > > > Don't know how it will behave as an MC amp.. The electrode > structure is to dramatic for such small signals , for my taste. > > But I do not doubt , that the white noise could be low. I would > worry about microphonics , at such low levels , though. > > Why for heavens sake use a tube with mu 6.5 as an mc headamp?! I > strongly guess the Joe asking this was joking... > > > And by the way , it is an excellent regulator triode :-) > > But 6AS7 and 6336 is better. > > A 6336 makes a purdy impressive linestage, too.... fairly low > Rp... ;-) (Actually, I've heard 6336 linestage. It sounded > surprisingly good!) > > > What does that YMMV means ? > > Your Mileage May Vary (what a weird way to say that your > experience may well be different... typically American, I'd say in > my best Swissgerman... ;-) > > © > ========================================================================= From: Steven S Subject: [JN] 12B4 project ideas? Date: Tue, 14 Aug 2001 21:39:38 -0400 (EDT) Source: Sound Digest Archive v02.n946 I've got a stash of mighty nice cryo'd 12b4's (thanks bill!) that i'm planning on using 2 for my "long term" project (12b4's + 813's + ??) which leave me with a few to spare. I've been taken with headphone amps lately since i'm never sitting long enough on the couch to fire up the big guys. So.. my current thought is to use a input tranny->12B4->output tranny for a good single tube amp. Throw in a selector switch, volume pot and some fiddly bits and a good psu... done. Anyone tried this with this tube? Any thoughts/comments? ========================================================================= From: pderl@btinternet.com Subject: Re: [JN] 12B4 project ideas? Date: Wed, 15 Aug 2001 10:25:52 +0100 (BST) Source: Sound Digest Archive v02.n946 Hello. No comment about the headphones, but I have driven 813s with 12B4s. very acceptable although I now use 6BX7 which provides a little more gain for similar Ra. Paul > > I've got a stash of mighty nice cryo'd 12b4's (thanks bill!) that i'm > planning on using 2 for my "long term" project (12b4's 813's ??) which > leave me with a few to spare. I've been taken with headphone amps lately > since i'm never sitting long enough on the couch to fire up the big guys. > > So.. my current thought is to use a input tranny->12B4->output tranny for > a good single tube amp. Throw in a selector switch, volume pot and some > fiddly bits and a good psu... done. > > Anyone tried this with this tube? Any thoughts/comments? > > ========================================================================= From: "Daniel J. Marshall" Subject: [JN] Re: 12 inch Tannoy Golds Date: Tue, 30 May 2000 11:20:22 -0700 Source: Sound Digest Archive v02.n560 > I just got a pair of 12" Golds, and a summer project of mine > will be to build some boxes. I have no technical data for > the drivers or crossovers, so I don't know where to begin. > I've heard that many cabinets built by Tannoy were too small > for the drivers (i.e. give a higher WAF while sacrificing bass). > > I'd appreciate any help any of you can offer! Thanks! > > Randy Hi Randy, Some Golds have paper surrounds and some have Butyl, or foam, I forget, Butyl I think. They would have different fs and Qts, therefore different parameters and different enclosure requirements. I have experience only with the paper surrounds. The paper surround units have a rather High Qts, something like .416, or .436, I forget which. Their fs was around 49 Hz. If yours have paper surrpounds and are nearer the 40 Hz fs spec, they would have a lower Qts, perhaps something near 0.383 which is considered as the ideal value for maximally-flat, fourth-order Butterworth alignment. VAS was fairly small, though I don't recall the exact value at the moment. I had the 12" Golds for about 30 years in 4 cu ft boxes which were made for them a long while before Thiele and Small published their work on speaker design. The boxes were tuned below fs to 43 Hz (later to be recognized as something approaching a fourth-order Chebychev alignemnt sans the math, purely green-thumbing it at the time). This worked fairly well, but they did tend to have a bit of a hump around 70 Hz and fell off quite a bit at 40 Hz, plus the speaker centers were way too close to the floor. The bass was good enough that most everyone seemed to complement it though. I once tuned the enclosures down to 35 Hz and used a 2nd-order equalizer with 9 dB boost at 35 Hz. Tuned in this manner they had whompin bass, the kind that would kick you right in the gut, sounded good, if you are a bass freak like me, rather than a purist. And you could lean on them quite hard w/o overdrive. This would be an excelelnt for Rock, and the like. I once converted one of the enclosures to a TL. Path length was 5.5 ft, stuffed with Dacron. The bass was cleaner and more extended than with the normal duct loaded enclosure, less of it though, but still enough for most. TLs would quite possibly be the best for classical music and the like. If I were to build new enclsures, I think I would make a pair of TL towers, perhaps four ft tall and perhaps 15 inches square with the speakers at the top, at ear level. The TL I fashioned in one of the existing enclosures was not optimal, and a bit too small in overall dinmensions, so a new, proper design likely would give you better bass response. Such a TL tower design was published by Focal with the speaker at the top and a chamber behind which exhausted downward at the back, then back up to the bottom side of the chamber, then downward, terminating at the front (at floor level). This seems to be a pretty good design. I built another one for a pair of 8 inch Audax speakers and it fell right into place, first try. It sounded good, with clean extended bass. The Tannoys seemed to never have really clean, tight bass in any other enclosure, though the 35 Hz equalized scheme sounded pretty impressive, if you like a lot of bass. By slanting the pack partition in the TL, you achieve a tapered line with an entrance cross section about the size of the active area of the cone, tapering to something like 1/2 of this value at the terminus. Stuffing was nominally 1/2 lb per cu ft, though distributed such that it varied from twice density at the entrance to nothing at the terminus with extra stuffing in the speaker chamber, tuned to taste. Someone here on the list disputed this approach the last time it was discussed claiming better results by doing just the opposite, though I never tried it. Dan Marshall ========================================================================= From: Tim_Bailey@medibank.com.au Subject: [JN] Re: 12 inch Tannoys Date: Thu, 1 Jun 2000 10:45:51 +1000 Source: Sound Digest Archive v02.n561 Lucky devil, Go to the Tannoy web site and look up your drivers as a first step. then get the actual pair measured individually, for their actual TS parameters. Then build the biggest box you can, and use an EBS (overdamped reflex shelf dip alignment in the bass), which will allow you to use corner room gain to get flat and deep bass in room. Someone on this group can explain EBS. Also compensate for your baffle width dip , a shelving dip which starts higher up than room gain and will leave a 2- 4 db dip in the 'forward / direct' response of the spkrs in the upper bass. For smoothly matching room gain, remember to position the woofer centre (and yourself), at 3 unequal distances from side / rear walls and the floor. eg 1:1.5:2.25. Regards Tim Bo ========================================================================= From: Tim_Bailey@medibank.com.au Subject: [JN] Re: 12 inch Tannoys Date: Thu, 1 Jun 2000 13:27:19 +1000 Source: Sound Digest Archive v02.n561 10 or 12 inch for a smallish box. ========================================================================= From: "Chris Beck" Subject: Re: [JN] 12SN7 Date: Fri, 19 Feb 1999 11:32:48 -0600 Source: Sound Digest Archive v02.n051 Yup, same thing. Also, 12SN7's are usually available cheaper than 6SN7's. Most audio types have an aversion to 12V tubes. Something to do with heater cathode coupling at the higher filament voltages. If you are concerned, use DC on the filaments. That's at least the way I understand it. Maybe others have more experience with this area? Chris Beck See my web page at: http://www.execpc.com/~n9zes/index.htm - ---------- > From: Richard C Nevill > To: Sound Practices > Subject: [JN] 12SN7 > Date: Friday, February 19, 1999 10:29 AM > > > I found one of these fellows and am wondering whether it is the same as a > 6SN7, except of course for the heater voltage? > > Thanks people > > Richard Nevill > > > ========================================================================= From: Richard C Nevill Subject: [JN] 12SN7 Date: Fri, 19 Feb 1999 12:29:39 -0400 (AST) Source: Sound Digest Archive v02.n051 I found one of these fellows and am wondering whether it is the same as a 6SN7, except of course for the heater voltage? Thanks people Richard Nevill ========================================================================= From: Simon Busbridge Subject: Re: [JN] 12SN7 Date: Fri, 19 Feb 1999 16:39:36 +0000 (BST) Source: Sound Digest Archive v02.n051 Yep Simon Busbridge, BSc(Hons) PhD CPhys MInstP School of Engineering University of Brighton Lewes Road Moulsecoomb Brighton BN2 4GJ UNITED KINGDOM Tel: 0044 (0)1273 642542 Fax: 0044 (0)1273 642327/642301 e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com On Fri, 19 Feb 1999, Richard C Nevill wrote: > > I found one of these fellows and am wondering whether it is the same as a > 6SN7, except of course for the heater voltage? > > Thanks people > > Richard Nevill > > > > ========================================================================= From: Martin Seddon Subject: [JN] 12SN7 Date: Sun, 21 Feb 1999 21:25:12 +0000 Source: Sound Digest Archive v02.n053 hello joes, What about the 12SX7? And if it's the same as a 12SN7 why SX? The RCA ones I got have the grey internal coating - why? VTV did an article. I want to try them in a phono stage. While I'm here can anyone tell me if I can put a VR gas tube (OA2, 0B2) under the cathode of the 46 of my 56 DC 46 IT 300B amp in the making? IE for fixed bias. I guess the DC conditions would be a bit hard to set up ... then drift?? Can't find this one in the archives but sorry if old hat. Thanks to all for all the info, entertainment and good company. Martin (lurking class joe) ========================================================================= From: "PEARL Cust Serv" Subject: Re: [JN] Re: 13e1 se ul amps Date: Tue, 27 Jun 2000 14:28:22 -0600 Source: Sound Digest Archive v02.n592 Paul@13E1.com wrote: > The US number for 13E1 is 7972. > > Paul > Tim Bailey wrote: >> >> Bill et al, >> >> Yeah OK its a regulator tube, not a transmitter tube. So?! Hey ! ! I was *curious* So there . . . Btw, I have one of a 7242 . . . a beer can sized triode with 6 (six) heaters, 6 (six) cathodes, 3 control grids and two *great big* STOUT graphite plates. All the "of kind" elements are wired in parallel and the critter has a Gm of 100,000 umho, a mu of about 6 as I recall and a correspondingly low rp. Two would make one *hell* of a stereo linestage . . . and no, I do NOT where to get these, this one came along as the "closer" in a deal . . . >> Bill, IHT means 'indirectly heated triode'. I know . . .I already doped out the MLA . . . . (Multi Letter Acronym) SNIP . . . >> This non-technical systemicist and lurker will now shut up for a while. >> >> Warmest, >> Tim B Bill - PEARL, Inc. ========================================================================= From: Tim_Bailey@medibank.com.au Subject: [JN] Re: 13e1 se ul amps Date: Tue, 27 Jun 2000 17:38:58 +1000 Source: Sound Digest Archive v02.n592 Bill et al, Yeah OK its a regulator tube, not a transmitter tube. So?! Bill, IHT means 'indirectly heated triode'. UL?, well it works better that way at 500 volts HT. Allen W, the guy's name is Patrick Turner, he and your associate Joe R are 'at odds', so I didn't mention it, but you asked. (Have been through a bit lately but SWMBO insists I get rid of 'all this junk' and so I must send the tuner / case soon!). [Oh to have Ted Riesz's more tolerant wife around. His house is solid brick, so he can fit more stuff in without it starting to bulge! ] Patrick is the guy who rebuilt/modded the old tubed Kenwood Receiver I now use as my Radio, fm ss stereo decoder (from UK Studioi 12) other wise all tube, and; wide bandwidth audio on AM radio (random long wire, with an ATU ie a big multisection vane cap and a taped coil). I don't need / want digital radio! NB The TV interference it caused is now fixed. I posted about this a while back. This non-technical systemicist and lurker will now shut up for a while. Warmest, Tim B the Audio scrounger, aka insanus vulpis instar, aka the measurement sceptic ========================================================================= From: "Paul@13E1.com" Subject: Re: [JN] Re: 13e1 se ul amps Date: Tue, 27 Jun 2000 19:13:57 +0100 Source: Sound Digest Archive v02.n592 The US number for 13E1 is 7972. Paul - ----- Original Message ----- From: To: Sent: Tuesday, June 27, 2000 8:38 AM Subject: [JN] Re: 13e1 se ul amps > > > Bill et al, > > Yeah OK its a regulator tube, not a transmitter tube. So?! > > Bill, IHT means 'indirectly heated triode'. > > UL?, well it works better that way at 500 volts HT. > > Allen W, the guy's name is Patrick Turner, he and your associate Joe R are 'at > odds', so I didn't mention it, but you asked. (Have been through a bit lately > but SWMBO insists I get rid of 'all this junk' and so I must send the tuner / > case soon!). > > [Oh to have Ted Riesz's more tolerant wife around. His house is solid brick, so > he can fit more stuff in without it starting to bulge! ] > > Patrick is the guy who rebuilt/modded the old tubed Kenwood Receiver I now use > as my Radio, fm ss stereo decoder (from UK Studioi 12) other wise all tube, and; > wide bandwidth audio on AM radio (random long wire, with an ATU ie a big > multisection vane cap and a taped coil). I don't need / want digital radio! NB > The TV interference it caused is now fixed. I posted about this a while back. > > This non-technical systemicist and lurker will now shut up for a while. > > > Warmest, > Tim B > > the Audio scrounger, aka > insanus vulpis instar, aka > the measurement sceptic > > > ========================================================================= From: tube@jump.net Subject: Re: [JN] Re: 13e1 se ul amps Date: Tue, 27 Jun 2000 20:55:18 -0500 Source: Sound Digest Archive v02.n592 PEARL Cust Serv wrote: > Btw, I have one of a 7242 . . . a beer can sized triode with 6 (six) > heaters, 6 (six) cathodes, 3 control grids and two *great big* STOUT > graphite plates. All the "of kind" elements are wired in parallel and the > critter has a Gm of 100,000 umho, a mu of about 6 as I recall and a > correspondingly low rp. > Two would make one *hell* of a stereo linestage . . . and no, I do NOT > where to get these, this one came along as the "closer" in a deal . . . > > Bill - PEARL, Inc. My Tung-Sol book says gm = 111 mmho, mu = 9, Rp = 82 ohms, 100 W. I am almost certain that this is 1 1/2 6528 tubes, except that the 3 plates and grids are tied together in the 7242, unlike the 2 plates and grids in the 6528. The only difference is that each plate in the 6528 is only rated at 30 W each, although they may in fact handle 33 W, which would then be 1/3 of the 7242, like the gm and Rp. Phil ========================================================================= From: "Paul@13E1.com" Subject: Re: [JN] Re: 13e1 se ul amps Date: Tue, 27 Jun 2000 22:08:34 +0100 Source: Sound Digest Archive v02.n592 > Btw, I have one of a 7242 . . . a beer can sized triode with 6 (six) > heaters, 6 (six) cathodes, 3 control grids and two *great big* STOUT > graphite plates. All the "of kind" elements are wired in parallel and the > critter has a Gm of 100,000 umho, a mu of about 6 as I recall and a > correspondingly low rp. I want some - NOW! Paul ========================================================================= From: "Paul@13E1.com" Subject: Re: [JN] Re: 13e1 se ul amps Date: Tue, 27 Jun 2000 22:12:33 +0100 Source: Sound Digest Archive v02.n592 On second thoughts, this one would take some driving - you could probably use the Ca-g as a filter in your power supply! Paul - ----- Original Message ----- From: PEARL Cust Serv To: Sent: Tuesday, June 27, 2000 9:28 PM Subject: Re: [JN] Re: 13e1 se ul amps > Paul@13E1.com wrote: > > The US number for 13E1 is 7972. > > > > Paul > > > Tim Bailey wrote: > > >> > >> Bill et al, > >> > >> Yeah OK its a regulator tube, not a transmitter tube. So?! > Hey ! ! I was *curious* So there . . . > Btw, I have one of a 7242 . . . a beer can sized triode with 6 (six) > heaters, 6 (six) cathodes, 3 control grids and two *great big* STOUT > graphite plates. All the "of kind" elements are wired in parallel and the > critter has a Gm of 100,000 umho, a mu of about 6 as I recall and a > correspondingly low rp. > Two would make one *hell* of a stereo linestage . . . and no, I do NOT > where to get these, this one came along as the "closer" in a deal . . . > > >> Bill, IHT means 'indirectly heated triode'. > I know . . .I already doped out the MLA . . . . (Multi Letter Acronym) > > SNIP . . . > > >> This non-technical systemicist and lurker will now shut up for a while. > >> > >> Warmest, > >> Tim B > > Bill - PEARL, Inc. > ========================================================================= From: "PEARL Cust Serv" Subject: Re: [JN] Re: 13e1 se ul amps Date: Tue, 27 Jun 2000 23:31:35 -0600 Source: Sound Digest Archive v02.n592 Steve Bench wrote > In a message dated 00-06-27 22:24:16 EDT, tube@jump.net writes: >> My Tung-Sol book says gm = 111 mmho, mu = 9, Rp = 82 ohms, 100 W. I am >> almost certain that this is 1 1/2 6528 tubes, except that the 3 plates >> and grids are tied together in the 7242, unlike the 2 plates and grids >> in the 6528. The only difference is that each plate in the 6528 is >> only rated at 30 W each, although they may in fact handle 33 W, which >> would then be 1/3 of the 7242, like the gm and Rp. > >> Phil > Cool! That would be a "plate" resistance of 9 (nine) ohms in inverted mode. > Hmmm! > -Steve WHAT a good idea . . . so a mu of 1/9 x a gain of or so 50 = a gain of 6 = 15dB . . . Perfectamundo . . . Now, with one of those 45,000umho, mu 50 Russkie single triodes that I have on the way as a driver, I think we're cookin' with gas here . . . 15dB of gain from a 9ohm, no f/b source . . . Hmmmmm indeedy weedy :>) Bill - PEARL, Inc. ========================================================================= From: "Jim Warwick" Subject: Re: [JN] Re: 13e1 se ul amps Date: Wed, 28 Jun 2000 00:14:20 -0400 Source: Sound Digest Archive v02.n592 'been looking for a pair of 7242s, or even 7241s...seems unobtainium. I've tried the 6528 in a linestage, IT coupled, low current. Big sound. Worth returning to and tweaking sometime... Regards, Jim > My Tung-Sol book says gm = 111 mmho, mu = 9, Rp = 82 ohms, 100 W. I am > almost certain that this is 1 1/2 6528 tubes, except that the 3 plates > and grids are tied together in the 7242, unlike the 2 plates and grids > in the 6528. The only difference is that each plate in the 6528 is > only rated at 30 W each, although they may in fact handle 33 W, which > would then be 1/3 of the 7242, like the gm and Rp. > > Phil > > ========================================================================= From: SBench@aol.com Subject: Re: [JN] Re: 13e1 se ul amps Date: Wed, 28 Jun 2000 00:41:48 EDT Source: Sound Digest Archive v02.n592 In a message dated 00-06-27 22:24:16 EDT, tube@jump.net writes: << My Tung-Sol book says gm = 111 mmho, mu = 9, Rp = 82 ohms, 100 W. I am almost certain that this is 1 1/2 6528 tubes, except that the 3 plates and grids are tied together in the 7242, unlike the 2 plates and grids in the 6528. The only difference is that each plate in the 6528 is only rated at 30 W each, although they may in fact handle 33 W, which would then be 1/3 of the 7242, like the gm and Rp. Phil >> Cool! That would be a "plate" resistance of 9 (nine) ohms in inverted mode. Hmmm! - -Steve ========================================================================= From: John Levreault Subject: Re: [JN] Re: 13e1 se ul amps Date: Wed, 28 Jun 2000 09:19:58 -0400 Source: Sound Digest Archive v02.n592 Jim Warwick wrote: > > 'been looking for a pair of 7242s, or even 7241s...seems unobtainium. The 7241 is a lower-mu tube than the 7242 or 6528. According to the Tung-Sol data sheet, "...one 7241 can replace four type 6080WA or 6AS7G regulator tubes." The nominal specs for the 7241 are: gm - 40mmho mu - 2.7 rp - 67ohms Pd - 100W Ip - 1.2A max (that's 1200ma!) Filament - 6.3V @ 7.5A Of course, these regulator tubes are not the most linear beasts in the world, so the actual specs can vary quite a bit from the above values. For grins, I did a quick 7241 load-line analysis. Bias at 150V and 500ma gives ~21W into a 200ohm load. Yikes! JL ========================================================================= From: "Paul@13E1.com" Subject: Re: [JN] Re: 13e1 se ul amps Date: Wed, 28 Jun 2000 19:15:43 +0100 Source: Sound Digest Archive v02.n592 You'll be lucky to get gm of 45 out of those Russian valves - only an exceptional one will give that - mind you in all other respects it is super! paul - ----- Original Message ----- From: PEARL Cust Serv To: Sent: Wednesday, June 28, 2000 6:31 AM Subject: Re: [JN] Re: 13e1 se ul amps > Steve Bench wrote > > > In a message dated 00-06-27 22:24:16 EDT, tube@jump.net writes: > > >> My Tung-Sol book says gm = 111 mmho, mu = 9, Rp = 82 ohms, 100 W. I am > >> almost certain that this is 1 1/2 6528 tubes, except that the 3 plates > >> and grids are tied together in the 7242, unlike the 2 plates and grids > >> in the 6528. The only difference is that each plate in the 6528 is > >> only rated at 30 W each, although they may in fact handle 33 W, which > >> would then be 1/3 of the 7242, like the gm and Rp. > > > >> Phil > > > Cool! That would be a "plate" resistance of 9 (nine) ohms in inverted mode. > > Hmmm! > > > -Steve > > WHAT a good idea . . . so a mu of 1/9 x a gain of or so 50 = a gain of 6 > = 15dB . . . Perfectamundo . . . > Now, with one of those 45,000umho, mu 50 Russkie single triodes that I > have on the way as a driver, I think we're cookin' with gas here . . . > 15dB of gain from a 9ohm, no f/b source . . . > Hmmmmm indeedy weedy :>) > > > Bill - PEARL, Inc. > ========================================================================= From: "Le Cleac'h J.-M." Subject: Re: [JN] Re: 13e1 se ul amps Date: Thu, 29 Jun 2000 09:35:34 +0200 Source: Sound Digest Archive v02.n593 Hello, I had lot of problems with my computer (and my mail files, lost a lot of them) so I couldn't follow that interesting thread. It seems to me that the kind of tubes you are discussing are quite similar to the tube I use in my Shabda amplifier. (I found the first ones in a 500volts 500mA regulated supply). So, in place of using it in UL, why not try to use it screen driven. One major advantage of such design is that it allows you to have no capacitor at all in the amplifier. Here is an ASCII schematics of my Shabda amplifier (it exists several versions) (to look at the scheamtics, please set your display in COURRIER font.) 500V | o-------o---------o o------o | | )||( | | ( || ) OUTPUT CCS | )||( | | T2 ( || o------o | drain )|| o-----gate ( || | source )|| | | o T1 | | | INPUT plate | plate o---o---grid Uo-------screen T3 | cathod | o---grid | | | | cathod | | | | | R1 R2 R3 | R4 | | | | | o-----o-------o---o-----o | GROUND T3 = triode T2 = mosfet (or a cathod follower) T3 = medium to large power tetrod R3 can be replaced by an active element (constant curent sink) for better results. CCS is a cascode current source (Manfred Hubert's one is excellent) At point U you may obtain 300V peak to peak signals (and even more if CCS is perfectly adapted to T1) Another modification is to put the secondary of the OPT between R4 and ground for some local feedback for the output tube. Best regards, Jean-Michel Le Cleac'h,Paris, France ========================================================================= From: David Metz Subject: [JN] Re: 144dB, was DVD A/V system question. Date: Thu, 8 Jul 1999 18:29:41 -0700 Source: Sound Digest Archive v02.n199 >> My understanding of the 144db number is that *No* current hardware for >> music reproduction has signal-to-noise this good. Not in the recording >> studio and not in your house. Systems with signal-to-noise equal to that of >> true 20bit systems may just barely be doable with current technology (short >> of super-cooling all the circuits). This isn't just a DAC problem but >> applies to amplifiers etc. as well.(snip) > >Didn't I say this a couple of months ago? > >Scott. Whoops, sorry, been off-list for 6-8 months. - -- David Metz dnmetz@uniserve.com ========================================================================= From: Scott Grammer Subject: [JN] Re: 144dB, was DVD A/V system question. Date: Thu, 08 Jul 1999 19:55:58 -0400 Source: Sound Digest Archive v02.n199 David Metz wrote: > (snip) > > My understanding of the 144db number is that *No* current hardware for > music reproduction has signal-to-noise this good. Not in the recording > studio and not in your house. Systems with signal-to-noise equal to that of > true 20bit systems may just barely be doable with current technology (short > of super-cooling all the circuits). This isn't just a DAC problem but > applies to amplifiers etc. as well.(snip) Didn't I say this a couple of months ago? Scott. - -- TubeDude's Webpage of Vacuum Tube Lore! http://www.cdc.net/~tubedude/ Smoke Free Youth! http://www.cdc.net/~tubedude/smokefreeyouth.html The Price of Privacy. http://www.cdc.net/~tubedude/privacy.html Chaos, panic, & disorder - my work here is done. ========================================================================= From: Kalman Rubinson Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Thu, 8 Jul 1999 20:17:50 -0400 (EDT) Source: Sound Digest Archive v02.n199 On Thu, 8 Jul 1999, Scott Grammer wrote: > Didn't I say this a couple of months ago? Dunno but, if you did, you weren't the only one. Kal ========================================================================= From: Scott Grammer Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Thu, 08 Jul 1999 22:52:37 -0400 Source: Sound Digest Archive v02.n200 David Metz wrote:(snip) > > Whoops, sorry, been off-list for 6-8 months. > > -- > David Metz dnmetz@uniserve.com David: Waitaminute, I didn't mean to aim that at you! :-) I meant to say that I said almost the exact same thing about 2 months ago, but no one seemed to believe me. I was not trying to chide you for repeating my sentiments. Sorry! Scott. - -- TubeDude's Webpage of Vacuum Tube Lore! http://www.cdc.net/~tubedude/ Smoke Free Youth! http://www.cdc.net/~tubedude/smokefreeyouth.html The Price of Privacy. http://www.cdc.net/~tubedude/privacy.html Chaos, panic, & disorder - my work here is done. ========================================================================= From: David Metz Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 9 Jul 1999 10:08:15 -0700 Source: Sound Digest Archive v02.n200 >Gang, > >>> My understanding of the 144db number is that *No* current hardware for >>> music reproduction has signal-to-noise this good. Not in the recording >>> studio and not in your house. Systems with signal-to-noise equal to that of >>> true 20bit systems may just barely be doable with current technology (short >>> of super-cooling all the circuits). This isn't just a DAC problem but >>> applies to amplifiers etc. as well.(snip) >> >>Didn't I say this a couple of months ago? > >"SO WHAT" is my comment, as I said the other day. Does Analog have 144dB >SN, no can you hear the difference, Yes. So who cares... > >The point is more information in any regard = better music. Assumming the >execution is carried out in a beneficial manner. > >Gordon > Indeed, my point isn't to discourage people from being interested in higher resolution digital at all (I certainly am!). I was hoping to point out that worrying about and possibly spending alot of money on systems that claim 24bit resolution may not be necessary (*) if a cheaper or better built 20 bit system is also available. It's unlikely that anyone will be able to hear the difference in word length and so people should probably concentrate on other equipment features. (*) The exception to the above is if there is lots of processing of the signal going on. Mixing in a studio, room correction etc. may all benefit from higher word lengths since this gives a larger number space to deal with issues like round off error. I think to a large extent we are agreeing, just coming at things from a different angle? Dave - -- David Metz dnmetz@uniserve.com ========================================================================= From: "Mike Hathaway" Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 9 Jul 1999 11:47:58 -0700 Source: Sound Digest Archive v02.n200 Gang: I would offer that the benefit of 24/96 systems isn't in the area of S/N, but rather in improvements obtained by bettering the Nyquist sampling rate. It isn't so much a mater of noise as it is eliminating signal errors, which is after all distortion of the most vile sort. Mike - -----Original Message----- From: David Metz To: J. Gordon Rankin Cc: sound@lists.io.com Date: Friday, July 09, 1999 10:43 AM Subject: Re: [JN] Re: 144dB, was DVD A/V system question. >>Gang, >> >>>> My understanding of the 144db number is that *No* current hardware for >>>> music reproduction has signal-to-noise this good. Not in the recording >>>> studio and not in your house. Systems with signal-to-noise equal to that of >>>> true 20bit systems may just barely be doable with current technology (short >>>> of super-cooling all the circuits). This isn't just a DAC problem but >>>> applies to amplifiers etc. as well.(snip) >>> >>>Didn't I say this a couple of months ago? >> >>"SO WHAT" is my comment, as I said the other day. Does Analog have 144dB >>SN, no can you hear the difference, Yes. So who cares... >> >>The point is more information in any regard = better music. Assumming the >>execution is carried out in a beneficial manner. >> >>Gordon >> > >Indeed, my point isn't to discourage people from being interested in higher >resolution digital at all (I certainly am!). I was hoping to point out that >worrying about and possibly spending alot of money on systems that claim >24bit resolution may not be necessary (*) if a cheaper or better built 20 >bit system is also available. It's unlikely that anyone will be able to >hear the difference in word length and so people should probably >concentrate on other equipment features. > >(*) The exception to the above is if there is lots of processing of the >signal going on. Mixing in a studio, room correction etc. may all benefit >from higher word lengths since this gives a larger number space to deal >with issues like round off error. > >I think to a large extent we are agreeing, just coming at things from a >different angle? > >Dave > > >-- >David Metz dnmetz@uniserve.com > > > ========================================================================= From: Allen Wright Subject: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 9 Jul 1999 14:08:18 -0400 Source: Sound Digest Archive v02.n200 David wrote: >>>if a cheaper or better built 20 bit system is also available. It's unlikely that anyone will be able to hear the difference in word length...<<< A good friend, Mark Conese of Ambient Studios in CT has been doing a lot of testing of digital systems in conjunction with SONY and Tom Jung of DSP Records around SONY's DSD recording system, and how it compares with the various PCM systems. He told me that A/B tests oncomparing digitally processed signals (A to D then back again) directly with their live mic feed source (of grand piano) showed very clear improvements in quality starting from 16/44.1, up through 20/44.1 and 24/44.1, then 24/96 and finally 24/192. Apparently it was not a problem to hear the changes with a signal path comprising a 417A mic preamp into the digital systems/direct bypass, and then into tube poweramps and Tannoys. Each was better than the last, but none _really_ close to the analog feed - all having that "digital" something. Apparently the DSD system was something else, and according to Mark didn't have that "digit" signature. It still was different to the pure analog but very much closer in their opinion. I for one will not be bothering to upgrade my digital playback untill the DSD based SuperAudio CD arrives. It went on sale in Japan a month or two ago and is scheduled for worldwide release across '99. Heard it in a demo at the AES and I was very happy with what I heard - best digital based demo I have ever heard - by a long way. Allen (VSE) ========================================================================= From: bobc@cwix.com Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 09 Jul 1999 14:27:58 -0400 Source: Sound Digest Archive v02.n200 - ----- Original Message ----- From: David Metz To: J. Gordon Rankin Cc: Sent: Friday, July 09, 1999 1:08 PM Subject: Re: [JN] Re: 144dB, was DVD A/V system question. > It's unlikely that anyone will be able to > hear the difference in word length and so people should probably > concentrate on other equipment features. I am sorry but I have to disagree. I personally have not had the opportunity to compare 24/96 with older players, but I have spoken to people who have and they clearly hear a difference. I have spoken to Stan Warren (I current use one of his Teac mods) and he has also clearly found an improvement. What Gordon says makes a great deal of sense. Bob ========================================================================= From: "J. Gordon Rankin" Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 9 Jul 99 09:28:51 -0400 Source: Sound Digest Archive v02.n200 Gang, >> My understanding of the 144db number is that *No* current hardware for >> music reproduction has signal-to-noise this good. Not in the recording >> studio and not in your house. Systems with signal-to-noise equal to that of >> true 20bit systems may just barely be doable with current technology (short >> of super-cooling all the circuits). This isn't just a DAC problem but >> applies to amplifiers etc. as well.(snip) > >Didn't I say this a couple of months ago? "SO WHAT" is my comment, as I said the other day. Does Analog have 144dB SN, no can you hear the difference, Yes. So who cares... The point is more information in any regard = better music. Assumming the execution is carried out in a beneficial manner. I've heard it, maybe some of you should. Gordon =======> Wavelength Audio <======= mailto:waudio@cinti.net http://www.WavelengthAudio.com ph.fx. 513-271-4186 USA ========================================================================= From: "Norman Luttbeg" Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 09 Jul 1999 14:15:31 -0500 Source: Sound Digest Archive v02.n201 I would have to agree with Bob. When I had the dCS 972 up and down sampler, you could select the output word size up to 24. I could hear no difference until I got below 20; a substantial decline by 16; and unlistenability below 10. Norm >----- Original Message ----- >From: David Metz >To: J. Gordon Rankin >Cc: >Sent: Friday, July 09, 1999 1:08 PM >Subject: Re: [JN] Re: 144dB, was DVD A/V system question. > > >> It's unlikely that anyone will be able to >> hear the difference in word length and so people should probably >> concentrate on other equipment features. > >I am sorry but I have to disagree. I personally have not had the >opportunity to compare 24/96 with older players, but I have spoken to people >who have and they clearly hear a difference. I have spoken to Stan Warren (I >current use one of his Teac mods) and he has also clearly found an >improvement. > >What Gordon says makes a great deal of sense. ========================================================================= From: David Metz Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 9 Jul 1999 15:06:12 -0700 Source: Sound Digest Archive v02.n201 >----- Original Message ----- >From: David Metz >To: J. Gordon Rankin >Cc: >Sent: Friday, July 09, 1999 1:08 PM >Subject: Re: [JN] Re: 144dB, was DVD A/V system question. > > >> It's unlikely that anyone will be able to >> hear the difference in word length and so people should probably >> concentrate on other equipment features. > >I am sorry but I have to disagree. I personally have not had the >opportunity to compare 24/96 with older players, but I have spoken to people >who have and they clearly hear a difference. I have spoken to Stan Warren (I >current use one of his Teac mods) and he has also clearly found an >improvement. > >What Gordon says makes a great deal of sense. > >Bob From this and other replies it sounds like I need to hear better demos. I certainly look forward to them! Dave - -- David Metz dnmetz@uniserve.com ========================================================================= From: "Jeff Mai" Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 9 Jul 1999 15:42:40 -0500 Source: Sound Digest Archive v02.n201 This topic was worked over pretty thoroughly in rec.audio.tech several months ago. My knowledge on the subject is fairly limited, but that debate led me to my own conclusions. Note that this is strictly opinion, and I reserve the right to change my mind in the event that I have no idea what I'm talking about. First it seems that 18 bits ought to be plenty of resolution. Why would you need more than 108dB of dynamic range? The way I understand it, in order to get anything useful out of the last 4 bits of a 24bit DAC, it needs to be supercooled to overcome internal noise. I do have a question regarding word length. Is it significant that the LSB represents a much greater change in volume to our ear at low levels than it does at near high volume levels? Second, sampling at 44.1kHz should work fine. The way I understand Nyquist is that *any* part of the signal missed when sampling at 44.1kHz but sampled at 96kHz is not an error but instead is by definition out of the sampling bandwidth (greater than or equal to 22.05kHz.) Am I understanding this correctly? I believe that carefully used, properly engineered 18bit/44.1kHz equipment should be capable of equaling the sound quality of 24bit/96kHz equipment. The trouble starts with the words "carefully used, properly engineered." The 24bit/96kHz stuff may very well sound better because this largely hasn't been the case. Jeff - ---------- > From: Mike Hathaway > To: sound@lists.io.com > Subject: Re: [JN] Re: 144dB, was DVD A/V system question. > Date: Friday, July 09, 1999 1:47 PM > > Gang: > > I would offer that the benefit of 24/96 systems isn't in the area of S/N, > but rather in improvements obtained by bettering the Nyquist sampling rate. > It isn't so much a mater of noise as it is eliminating signal errors, which > is after all distortion of the most vile sort. > > Mike ========================================================================= From: Thomas Danley Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Fri, 09 Jul 1999 18:31:20 -0500 Source: Sound Digest Archive v02.n201 Jeff Mai wrote: > This topic was worked over pretty thoroughly in rec.audio.tech several > months ago. My knowledge on the subject is fairly limited, but that debate > led me to my own conclusions. Note that this is strictly opinion, and I > reserve the right to change my mind in the event that I have no idea what > I'm talking about. > > First it seems that 18 bits ought to be plenty of resolution. Why would > you need more than 108dB of dynamic range? The way I understand it, in > order to get anything useful out of the last 4 bits of a 24bit DAC, it > needs to be supercooled to overcome internal noise. > > I do have a question regarding word length. Is it significant that the LSB > represents a much greater change in volume to our ear at low levels than it > does at near high volume levels? Hi Jeff Your last question not only "hits the nail on the head" but identifies the primary (imho) weakness of the digital format. Our current Digital systems are voltage incremental systems and what we hear as a change in loudness is "power" which is not the same thing. For example on a 16 bit format, assume 1 volt is the maximum signal level and with 65,536 increments, each represents 1/65,536 volts. Since "Loudness" is 20*log (voltage), the 16bit system mentioned, falling 1 increment below full signal is a -.000133 dB change in level, very fine resolution. Interestingly half of the total increments (65,536/2) are used to resolve the highest 6 dB and the rest,the remaining 90 dB. As the signal level decreases, the larger (in dB) each increment becomes , by the time you get to -58 dB, each increment is .101 dB and at -90 dB the lowest signal level bit is a 6dB change in level. At the signal level where an LP has reached its noise floor (@-72 dB) the signal on the CD is 17 voltage increments (+24 dB) from its noise floor but here one voltage increment is more than a .5 dB change in level. This situation results in the short musical peaks recorded with the greatest resolution where your ears and speakers have the least and the quiet (usually longer) parts recorded with less resolution where your ears are more sensitive and speakers more linear. This seems to me a non-optimal situation compared to what one would get if this were a Log based system, then 16 bits would give you 65,536 steps .00146 dB each from -96 to 0 dB, but hey I'm not in charge and it would probably cost more. Bottom line is as the level decreases, sampling granularity increases so a 24 bit system has less granularity in the average signal level range. Best Regards, Thomas Danley Intersonics Technology Corp ========================================================================= From: "Bill Gaw" Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Sat, 10 Jul 1999 13:50:08 -0400 Source: Sound Digest Archive v02.n201 The difference is definately there. I have a DV-09 DVD player outputing to an EAD Signature Preamp with 20 bit/48 kz chips, top of the line, and the DV-09 has internal 24/96 khz chips which output to Allen Wright's preamps. The 20 bit external chips lose some of the swense of space and other ambience info compared to the 24 bit internal DAC's. I also have a couple ofthe CD's by Chesky which have the exact same programs as the DVD's, and they lose even more info. So there reallyu is a difference, and Allen Wright has told me of listeningto the Sony system, and feeling it was even more superior. Bill - -----Original Message----- From: David Metz To: Date: Friday, July 09, 1999 6:28 PM Subject: Re: [JN] Re: 144dB, was DVD A/V system question. >>----- Original Message ----- >>From: David Metz >>To: J. Gordon Rankin >>Cc: >>Sent: Friday, July 09, 1999 1:08 PM >>Subject: Re: [JN] Re: 144dB, was DVD A/V system question. >> >> >>> It's unlikely that anyone will be able to >>> hear the difference in word length and so people should probably >>> concentrate on other equipment features. >> >>I am sorry but I have to disagree. I personally have not had the >>opportunity to compare 24/96 with older players, but I have spoken to people >>who have and they clearly hear a difference. I have spoken to Stan Warren (I >>current use one of his Teac mods) and he has also clearly found an >>improvement. >> >>What Gordon says makes a great deal of sense. >> >>Bob > >>From this and other replies it sounds like I need to hear better demos. I >certainly look forward to them! > >Dave > > >-- >David Metz dnmetz@uniserve.com > > > ========================================================================= From: Kalman Rubinson Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Sat, 10 Jul 1999 16:25:11 -0400 (EDT) Source: Sound Digest Archive v02.n201 On Sat, 10 Jul 1999, Bill Gaw wrote: > The difference is definately there. I have a DV-09 DVD player outputing to > an EAD Signature Preamp with 20 bit/48 kz chips, top of the line, and the > DV-09 has internal 24/96 khz chips which output to Allen Wright's preamps. > The 20 bit external chips lose some of the swense of space and other > ambience info compared to the 24 bit internal DAC's. I also have a couple > ofthe CD's by Chesky which have the exact same programs as the DVD's, and > they lose even more info. So there reallyu is a difference, and Allen Wright > has told me of listeningto the Sony system, and feeling it was even more > superior. With 24/96 sources, I suggest that the difference has less to do with the 24 vs. 20bits than it does with the 48 vs. 96KHz sampling rate. In fact, it probably has a lot to do with the downsamping software used. I don't think this is a fair test. Kal ========================================================================= From: Conrad Drake Subject: [JN] Re: 144dB, was DVD A/V system question. Date: Sun, 11 Jul 1999 22:37:25 +0800 Source: Sound Digest Archive v02.n202 > Date: Fri, 9 Jul 1999 15:42:40 -0500 > From: "Jeff Mai" > Subject: Re: [JN] Re: 144dB, was DVD A/V system question. > > > Second, sampling at 44.1kHz should work fine. The way I understand Nyquist > is that *any* part of the signal missed when sampling at 44.1kHz but > sampled at 96kHz is not an error but instead is by definition out of the > sampling bandwidth (greater than or equal to 22.05kHz.) Am I understanding > this correctly? > > I believe that carefully used, properly engineered 18bit/44.1kHz equipment > should be capable of equaling the sound quality of 24bit/96kHz equipment. > The trouble starts with the words "carefully used, properly engineered." > The 24bit/96kHz stuff may very well sound better because this largely > hasn't been the case. Let me add, that as an engineer, sampling at or near the Nyquist rate is _not_ proper engineering. Sampling at 44.1kHz will _never_ "work fine". The normal benchmark is to oversample about 5 times as this allows sensible anti-aliasing filter arrangements. And when yon audiophile wants 80+db of "correct" behaviour (vs the standard engineering 20db rule of thumb) things get quite tough. Anyone trying to do ADC or DAC at less than 110.5Khz is asking for a lot of problems (read artifacts around 22.1 and 0 - stuff that gives headaches or screws with room ambience.) Then we can get (back) into the arguement about whether 18/44.1Khz is "enough". Conrad D - -- Direct West Invs. Solutions for Embedded Systems. conrad.drake@directwest.iinet.net.au (ph)+61 8 9285 1000 http://directwest.iinet.net.au (mb)+61 40 747 1611 12 Gayton Road, City Beach, WA 6015 AUSTRALIA ========================================================================= From: "Norman Tracy" Subject: RE: [JN] Re: 144dB, was DVD A/V system question. Date: Mon, 12 Jul 1999 01:28:10 -0500 Source: Sound Digest Archive v02.n202 Gordon & Joe's, Oh wow, this thread has been going on in one form or another for as long as we have been talking audio on the Internet! Did anyone ever answer Gordon's original question about the variable audio outs on a DVD player? If so I missed it, let me know the player that does that. Without an answer for JGR's question we got sidetracked into: > >> My understanding of the 144db number is that *No* current hardware for > >> music reproduction has signal-to-noise this good. Not in the recording > >> studio and not in your house. Systems with signal-to-noise > equal to that of > >> true 20bit systems may just barely be doable with current > technology (short > >> of super-cooling all the circuits). This isn't just a DAC problem but > >> applies to amplifiers etc. as well.(snip) > > > >Didn't I say this a couple of months ago? Which is correct in a certain context. For example go to the major semiconductor makers web sites and look for industrial non-audio ADC/DACs at +16 bits. You will find them few and far between. In audio work we accept compromises in areas like differential linearity and absolute output accuracy which would never be tolerated in industrial, military, or scientific applications. Sure today the only REAL 22-24 bit ADCs are so slow they are only good for scales where we can wait seconds for the sample to settle. I am sure the point of allowing the DVD audio specs to include up to 24 bit samples is HEADROOM for future development. If one lesson was learned from CD it was to keep the standard FAR ahead of the current state of the art because we always understatement the pace of technical advancement. I remember in my DC circuit analysis class the instructor waving his arms over his head sweeping all around the classroom telling us a 1 F capacitor would never be made because it would be as big as this room. Now the car audio guys buy them by the 6-pack to keep those subs a thumping! I find it especially ironic to see this being hashed out on the Joe list given the dynamic range and SNR of the typical single ended tube amp. In one of his talks at a VSAC John Camille (always one to hold our feet to the technical fire all the while remaining loyal to the Triode Way) suggested the obvious. Take your amps clipping voltage then measure its residual noise output in system, do a little math and see your SNR and equivalent bits. In this thought experiment he measures at the speaker (quiet track output for the noise measurement) and based it on 7.07 VRMS into 100 dB/W/M speaker i.e. 6.25 watts into 8 ohms. John's Effective Number Of Bits (ENOB) table goes something like this: Hum & Noise SNR ENOB Remarks (VRMS) (dbV) (bits) - -------------------------------------------------------- 100 mV 37 6 10 mV 57 9 Typical system 1 mV 77 13 Excellent system 100 uV 97 16 Excellent system 10 uV 117 19 Extreme measures required 1 uV 137 23 God's domain 100 nV 157 26 God's domain Of course if we give up on 300Bs, 2A3s, and such and use my 83 dB/W/M Stax ESL-F83 with a muscle amp the numbers will scale up. So, then we trade trying to go for very extreme low noise to simply extreme low noise and back to trying to make a good sounding 200-300 wpc amp. Which is why I liked one of Gordon's replies: > "SO WHAT" is my comment, as I said the other day. Does Analog have 144dB > SN, no can you hear the difference, Yes. So who cares... > > The point is more information in any regard = better music. Assuming the > execution is carried out in a beneficial manner. > > I've heard it, maybe some of you should. Well I have. For an outfit which bills itself as digital audio experts ACG was slow to come to 24/96. Being both busy and conservative I thought I could wait for a standard to emerge. HA! It finally dawned on me that like the computer industry I am part of by day my beloved high-end audio has discovered FUD as a marketing tool. FUD is FEAR, UNCERTAINTY, and DOUBT. When applied effectively FUD can both deny your competition sales and keep the market churning over in a constant cycle of hardware and software replacements. One answer is to opt out completely and start collecting 8-tracks. Problem is I am a committed (or is that certifiable) gearhead and music lover. So the siren song of the early adopter called. Now the neat thing about going with Super Audio Disks from Classic & Chesky is they are based on the original DVD video standard so no matter what happens with DVD-A vs. SACD these disks will always play in a DVD player. My current 96/24 rig is a Pioneer DV-414 player as transport outputting 96/24 to a modified ACG X-DAC 3.0 Signature. The input receiver on the X-DAC 3.0 is a CS8414 and the DAC a Crystal CS4390 24/48 DAC overclocked to 96k. Its been up and running for about two weeks now. Before the parts to upgrade X-DAC to 96/24 arrived I tried the DV-414's analog outs playing 44/16 and 96/24. Ho hum, big snooze. All too typical Japanese mid-fi easily bested by external DACs. The sound with a high-end 96/24 DAC/analog stage & PS? DAMN, WHY DID I WAIT THIS LONG TO GET STARTED! If back in my analog days a new turntable or tonearm had made this much improvement I would of been THRILLED! The good news is the gains seem to be both in the areas of ear candy for the equipment geek and musical emotional content for the music lover. Which is my bottom line test for if a technical change in an audio system is just something different or a true improvement. One example of this is the Livingston Taylor cut 'Isn't She Lovely' on Chesky. If Livingston Taylor isn't related to James Taylor he sure wants to be. Heard in 44/16 format I skipped past 'Isn't She Lovely' as just another JT knockoff. In 96/24 it pulled me into his performance and helped me understand the artist. Well its after 1AM so I will spare you any further Stereophile reviewer wann-a-b prose. Let's just say I cannot wait for more 96/24 disks to arrive casa Tracy. And the only downside seems to be the DV-414 is slower to queue up and start play compared to CD only transports. And my CDs all sound as good as ever, Gordon's right, it does make a excellent transport. happy listening Norman Tracy Audio Crafters Guild ntracy@galstar.com www.galstar.com/~ntracy/acg ========================================================================= From: "Hugh R. Dean" Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Mon, 12 Jul 1999 18:33:01 +1000 Source: Sound Digest Archive v02.n203 Excellent post, Norman. Very sensible. However, the odd thing about marketing hype and the FUD it creates is the resentment which surfaces when the fallacy is put to rest. Resentment = NO SALES!!! Someone recently pointed out that 65,536 gradations of a 1Vrms signal gives a resolution of 0.0031dB - pretty good, I figured. I don't believe I can hear a 1dBA difference. But, a sampling rate of 44.1KHz means a steep slope filter to remove artefacts right at the upper limit of audibility. This could have serious repercussions for music; a sampling rate of 96KHz would seem far more appropriate. Cheers, Hugh R. Dean Melbourne, Australia ========================================================================= From: "J. Gordon Rankin" Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Mon, 12 Jul 99 10:46:48 -0400 Source: Sound Digest Archive v02.n203 All, Remember what we are doing here! We record information in a digital format for replay. The resolution of the output is determined (in theory) by two factors rate and bits per sample. I have several Chesky CD's and DVD's of the same preformance. Believe me on my system it is very apparent the differences. Heck so apparent that I made a DAC and added it to the line! Gordon =======> Wavelength Audio <======= mailto:waudio@cinti.net http://www.WavelengthAudio.com ph.fx. 513-271-4186 USA ========================================================================= From: davidbarnett@aristotle.net (David Barnett) Subject: Re: [JN] Re: 144dB, was DVD A/V system question. Date: Mon, 12 Jul 1999 22:06:58 GMT Source: Sound Digest Archive v02.n204 On Mon, 12 Jul 1999 01:28:10 -0500, "Norman Tracy" wrote: > If Livingston Taylor >isn't related to James Taylor he sure wants to be. They're brothers. - --dnb ========================================================================= From: David Metz Subject: [JN] Re: 144dB, was DVD A/V system question. Date: Thu, 8 Jul 1999 18:29:41 -0700 Source: Sound Digest Archive v02.n212 >> My understanding of the 144db number is that *No* current hardware for >> music reproduction has signal-to-noise this good. Not in the recording >> studio and not in your house. Systems with signal-to-noise equal to that of >> true 20bit systems may just barely be doable with current technology (short >> of super-cooling all the circuits). This isn't just a DAC problem but >> applies to amplifiers etc. as well.(snip) > >Didn't I say this a couple of months ago? > >Scott. Whoops, sorry, been off-list for 6-8 months. - -- David Metz dnmetz@uniserve.com ========================================================================= From: Paul Butterfield Subject: 15.1 Surround!! WAS Re: [JN] Concert Hall Hell WAS: Re: Loudspeaker Designed by Alexande Date: Thu, 30 Nov 2000 17:11:23 -0500 Source: Sound Digest Archive v02.n749 r Calder? Oooooo, I gotta get me this kinda system for my Home Theater!! 15 (count 'em) holographic timealligned drivers* (with 1 horn) - -- Paul (Grinnin', & Duckin') Butterfield Squeakier Chair Recording Studio "Those who hear not the music think the dancers mad." ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ========================================================================= From: Larry Van Wormer Subject: [JN] Re: $15 CD Now Coupon Date: Wed, 15 Sep 1999 21:48:58 -0400 Source: Sound Digest Archive v02.n278 $15 off on any order of $30 or more. Not bad! > http://p01.com/r.d?GkGofQKsZCs=cdnow/from=rel:x:cdn:bk11906 ========================================================================= From: TubeGarden@aol.com Subject: [JN] 15" Lambda Acoustics on 80 Hz edgarhorns Date: Thu, 26 Apr 2001 18:09:47 EDT Source: Sound Digest Archive v02.n875 - --part1_3e.aca139c.2819f6ab_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Greets! Yup, they are on site :) Nick's drivers rated 99.5 dB... gain of horns tbd :) I am warming them with 1 mH in series and 33uF shunt... This is what Mother's really want... Happy Ears! Al B^} - --part1_3e.aca139c.2819f6ab_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit Greets!

Yup, they are on site :)

Nick's drivers rated 99.5 dB... gain of horns tbd :)

I am warming them with 1 mH in series and 33uF shunt...

This is what Mother's really want...

Happy Ears!
Al  B^}


- --part1_3e.aca139c.2819f6ab_boundary-- ========================================================================= From: "Jon Lane" Subject: [JN] 15" TC woofers for sale Date: Thu, 25 Jan 2001 07:54:05 -0700 Source: Sound Digest Archive v02.n792 Joes, Out of the original lot of ten, I still have a couple pairs of these left. Now I'll consider any interesting trades for the stragglers. Let me know; tube or transformer sets, interesting compression drivers, etc. Cost to make these was $200 each. With one edit, this was my original post: > I have a few extra pairs of specialized woofers I had made > for a project last year. They are new and unused. Cast, > four-legged frames, 3.5" flat wire coils, heavy copper > Faraday motors with _underhung_ geometry and precision > machined gaps, vented poles, hard paper cones, cloth > surrounds, flat lead-in wires woven into the rear > suspension. Xmax is 10+ mm. They're pretty much no-holds > barred, medium-to-high sensitivity 15" drivers. > > NomR: 12 ohms > Fs 25 Hz > Revc: 9.2 ohms > BL: 25.75 TM (!) > SPL: 94.25 dB > Qms: 6 > Qes: .27 > Qts: .25 > Vas: 355 litr. > Cms: 350 uM/N > Mms: 130 Gm. > > TC Sounds builds OEM for the better high-end brands. This > is a good opportunity to acquire a premium driver in the > class of the better vintage professional units for a > below-cost price since TC typically only builds 100 piece > lots. ========================================================================= From: "Donnelly, Scott (CC/DTM)" Subject: [JN] 16" 100 Hz Horn? Date: Wed, 29 Dec 1999 10:48:38 -0500 Source: Sound Digest Archive v02.n375 I thought that the length of a horn had to be 1/4 wavelength? In a recent posting, the length of t he Edgar 100 Hz horn was given as 16 inches, which is more like 1/8 wavelength. How can this work? Scott ========================================================================= From: TubeGarden@aol.com Subject: [JN]: 1624 ? Date: Thu, 22 Jun 2000 23:43:27 EDT Source: Sound Digest Archive v02.n589 Greets Jeets Neets! I have some nice 1624 I want to listen to wired triode. I have the filaments nicely lit at 2.48Vac. Anybody know the Mu and the Rp? My blind guess circuit sounded overdriven and underloaded, otherwise GREAT! Happy Ears! Al B^} ========================================================================= From: tube@jump.net Subject: Re: [JN]: 1624 ? Date: Sat, 24 Jun 2000 12:20:47 -0500 Source: Sound Digest Archive v02.n590 TubeGarden@aol.com wrote: > Greets Jeets Neets! > > I have some nice 1624 I want to listen to wired triode. I have the filaments > nicely lit at 2.48Vac. > > Anybody know the Mu and the Rp? > > My blind guess circuit sounded overdriven and underloaded, otherwise GREAT! > > Happy Ears! > Al B^} Hmmm. The plate draws 91 mA at 300 Vp and 0 Vg with 300 V on the screen. The screen draws 9mA at this point, so the total is 100mA at 300 V, 0 Vg. This give a "DC" plate resistance of 3000 ohms, which is NOT accurate for the 0 Vg curve, but is usually amazingly accurate for the point at which the tube is actually operated! Gm is about 4 or 5 mmhos at 300 V, for a mu of 12 to 15. Now that's interesting! This is like a 25 W metal plate 211! Phil ========================================================================= From: TubeGarden@aol.com Subject: [JN] 1624 Hoorah! Date: Tue, 27 Jun 2000 18:07:45 EDT Source: Sound Digest Archive v02.n592 Greets! I replaced the 2A3/6A3/6B4G with the five pin plus plate cap 1624 Xmit power pentode, wired triode... This DHP is killer at 150V B+ and +18V battery fixed bias giving 90mA thru a ubt-3. Never heard such slam, bam, thank you maam dynamics from a low budget SE :) Female voices are just so fine. Now, to find my mint copy of Surfin' Bird by the Trashmen. Happy Ears! Al B^} ========================================================================= From: "Paul@13E1.com" Subject: Re: [JN] 1624 Hoorah! Date: Wed, 28 Jun 2000 00:26:44 +0100 Source: Sound Digest Archive v02.n592 Hello Al. When you find that disc I think you'll discover that it was called "Surfer Bird" I lost my copy years ago Poppa oom mao mao! Paul - ----- Original Message ----- From: To: Sent: Tuesday, June 27, 2000 11:07 PM Subject: [JN] 1624 Hoorah! > Greets! > > I replaced the 2A3/6A3/6B4G with the five pin plus plate cap 1624 Xmit power > pentode, wired triode... This DHP is killer at 150V B+ and +18V battery fixed > bias giving 90mA thru a ubt-3. > > Never heard such slam, bam, thank you maam dynamics from a low budget SE :) > > Female voices are just so fine. Now, to find my mint copy of Surfin' Bird by > the Trashmen. > > Happy Ears! > Al B^} > > > > ========================================================================= From: Robert C Chambers Subject: Re: [JN] 1624 Hoorah! Date: Thu, 29 Jun 2000 09:35:01 -0400 (EDT) Source: Sound Digest Archive v02.n593 Hi Al- Is this a modified "Donkey", i.e. modification of the schemo you posted a week or so ago? Robert On Tue, 27 Jun 2000 TubeGarden@aol.com wrote: > Greets! > > I replaced the 2A3/6A3/6B4G with the five pin plus plate cap 1624 Xmit power > pentode, wired triode... This DHP is killer at 150V B+ and +18V battery fixed > bias giving 90mA thru a ubt-3. > > Never heard such slam, bam, thank you maam dynamics from a low budget SE :) > > Female voices are just so fine. Now, to find my mint copy of Surfin' Bird by > the Trashmen. > > Happy Ears! > Al B^} > > > > ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 1624 Hoorah! Date: Thu, 29 Jun 2000 17:28:56 EDT Source: Sound Digest Archive v02.n593 In a message dated 6/29/00 6:35:08 AM US Mountain Standard Time, rchamber@norwich.edu writes: > 1624 Xmit power > > pentode, wired triode RCA calls it a Beam Power Tube for Class C FM Telephony :) Al ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 1624 Hoorah! Mas macho Donkeyotee Date: Thu, 29 Jun 2000 17:26:28 EDT Source: Sound Digest Archive v02.n593 In a message dated 6/29/00 6:35:08 AM US Mountain Standard Time, rchamber@norwich.edu writes: > Is this a modified "Donkey", i.e. modification of the schema you posted a > week or so ago? > > Robert Yup! This is the mas macho Donkeyotee! 1624 has 25W plate dissipation rating, I only use a little over half at idle. Using AC 2.5 on the fils with a fil transformer and hummy pot on each 1624 About 5 mV of 120Hz at the speaker outputs... Magnificent! (IMHO) Happy Ears! Al B^} ========================================================================= From: Chris Beck Subject: [JN] 1625 amp update Date: Sat, 05 Feb 2000 15:19:41 -0600 Source: Sound Digest Archive v02.n435 Well, I futzed around with the amp a little today. I wired up a 12.6VDC supply using the 12.6VAC winding on the power tranny, and wired in a 6.3VAC tranny to run the 6SJ7's. I rearranged a few things and plugged it back in. Ahhhh, silence. The amp is quiet as a mouse with the input grounded. So, I hauled it upstairs and plugged it into the Edgarhorns. WOW, what a nice sound. It frankly toasted the PP SV83 amp, which didn't surprise me too much. It seems the PP amp really looses a lot of detail at the super low power levels I typically use on the horns. It opens up when I rock on the volume knob, but then the wife complains, the dogs run and hide, and the neighbors probably wonder where's the concert. The sound is big, warm, and clean. I don't know the "pentode" sound from the "triode" sound, but the amp just sounds good. The soundstage is spacious, there is tons of detail, and the sound is very punchy. I don't think it's quite as clean and open in the midrange compared to my SV572-10 amps, but it definitely has the "single ended" sound. Lot's of boogie factor in this amp. Not bad for pentodes, feedback, and Ultralinear connection in an old recycled chassis, with lots of help from Jack's output iron. I just downloaded that freeware analyzer program that Thorsten mentioned, so we'll give it a shot and see what it'll do measuring up this amp. I'll post my findings later. Well, off to listen some more. Boy, those 1625's are pretty. Just think, those tubes had "relatives" that helped us win WWII, flying around in B-17's and such. Neat. ENJOY! Chris http://www.execpc.com/~n9zes Here's some pics of the amp: http://www.execpc.com/~n9zes/1625seamp.html ========================================================================= From: Ross J Lahlum Subject: Re: [JN] 1625 amp update Date: Sat, 5 Feb 2000 19:06:17 -0600 Source: Sound Digest Archive v02.n436 On Sat, 05 Feb 2000 15:19:41 -0600 Chris Beck writes: > I rearranged a few things and plugged > it back in. Ahhhh, silence. The amp is quiet as a mouse with the input grounded. Wow, I've never heard a mouse with the input grounded - is that just because they can't make any noise that way? (Sorry, couldn't resist ;-) ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj. ========================================================================= From: Chris Beck Subject: Re: [JN] 1625 amp update Date: Sun, 06 Feb 2000 15:52:09 -0600 Source: Sound Digest Archive v02.n436 Hee hee, ho ho, pretty droll Ross :-)) Seriously, it's a nice, quiet amp with no signal. There's a tiny bit of noise from my rather kludged layout, but it's much better than my SE SV572-10 amps with the AC filaments. They are a little noisy on the horns, but on "regular" speakers, they are just fine. Chris Ross J Lahlum wrote: > On Sat, 05 Feb 2000 15:19:41 -0600 Chris Beck writes: > > > I rearranged a few things and plugged > > it back in. Ahhhh, silence. The amp is quiet as a mouse with the > input grounded. > > Wow, I've never heard a mouse with the input grounded - is that just > because they can't make any noise that way? > > (Sorry, couldn't resist ;-) > > ________________________________________________________________ > YOU'RE PAYING TOO MUCH FOR THE INTERNET! > Juno now offers FREE Internet Access! > Try it today - there's no risk! For your FREE software, visit: > http://dl.www.juno.com/get/tagj. ========================================================================= From: Chris Beck Subject: Re: [JN] 1625 amp update Date: Sun, 06 Feb 2000 20:06:16 -0600 Source: Sound Digest Archive v02.n437 Just did some measurements of the amp: Power output: about 7 watts. Sensitivity for full output: 350mV Full power freq. response is flat 20Hz to 20kHz, which is the limit of my PC based audio generator. I'm a little concerned about the lower power output compared to the 10watts that the "Fi" circuit states. However, I am using a 3.4K transformer vs. the 2.5K, so I think that is where my discrepancy may be. All voltages are right on. Also, you can see the amp is pretty darn sensitive. TOO sensitive, actually. I need to calculate the amount of feedback being applied and see where I may want to tweak it. I am tapping off the 8 ohm tap, and I am wondering if the original value was calculated for 16 ohms? I may need to reduce the value of the 8.2K resistor to compensate. Soundwise, the amp continues to impress. Horns and acoustic guitar sound very "woody" and full. There may be a little upper mid hardness, but a little 'tweaking' can take care of that. Later! Chris ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 1625 amp update Date: Sun, 6 Feb 2000 20:14:13 EST Source: Sound Digest Archive v02.n437 In a message dated 2/6/00 2:24:57 PM US Mountain Standard Time, rlahlum@juno.com writes: > Wow, I've never heard a mouse with the input grounded Obviously, you have never been the Dad of a teenage mouse :) Happy Ears and Tail! Al B^} ========================================================================= From: Chris Beck Subject: [JN] 1625 SE Ultralinear amp up and running! - long Date: Wed, 02 Feb 2000 20:39:16 -0600 Source: Sound Digest Archive v02.n431 Hey gang, Just got my version of the "Fi Primer" 6L6 SE UL amp up and running tonight. I had an old Baldwin organ tone generator chassis sitting around that looked like it might be able to donate it's power iron and choke for a simple project, and this one seemed a little different than the usual DHT project. Here's where the original schematic can be found: http://tinpan.fortunecity.com/saints/668/primer/index.html So, I decided I wanted to use 6SJ7GT tubes in place of the EF86, use tube rectification, and try out some 1625's after they were mentioned here on the group. I found a pile of them, all NOS RCA's, 1942 and 1943 vintage, along with some ceramic sockets. I had Jack at Electra-Print wind me up a pair of TM3KB trannies with 44% UL taps, ordered up the parts, and went to work. Details are: 5U4 rectifier into 4uF oil cap, into unknown fairly small choke - probably around 3 to 5H, into 100uF. That goes to the output. Then, 24K to 100uF, for the decoupling for the input stage. I reformed the existing Mallory can caps on the chassis just for kicks, and they all formed up great. Amazing. So, I get 355VDC to the output stage, and about 290VDC to the 6SJ7's. The 4uF cap off the rectifier is to get the required voltage. I found it was not very touchy at all, I went first 1uF, then 2, then 2.22, then 4. Between 1 and 4uF, the voltage went up about 50V. The ouput is biased with 400 ohms, giving 23V on the cathodes. Perfect. The 6SJ7 is using the values from the Fi circuit for plate load and screen, giving 110V on the plate, about 55V on the screen, and 2.0V on the cathode. Total cathode R is about 1700 ohms. All bypass and coupling caps are per the schematic and are Nichicon Muse. The .047 coupling cap is an Angela Tin and Polyprop. Thought I'd try some. Resistors are a mix of carbon comp and a few metal oxides, Xicon brand. Feedback R is 8.2K taken from the 8 ohm tap. I'm not sure if this is optimal yet. Filaments are 6.3VAC on the input tubes, and 12VDC regulated on the 1625's by an external supply for testing purposes. At first I thought the filament winding was 6.3VAC on this tranny, until I fired it up with the 6SJ7's in there. I thought, MAN, these tubes are bright. Then I put the meter across the pins and read 13V. DOH!!!! So, I just used half the winding and the center tap to give 6.3V for now. I'll rig up a DC supply using Schottky diodes for the outputs and try running the SJ's in series from that 12VDC. That will be the simplest to start with. Ok, how's it sound? Well, I'm using my Rat Shack TQWT speakers in the basement right now. There's a little hum in the amp, either from magnetic coupling or some funky grounding. The wiring was quick and dirty, just to test the concept. It's not pretty, and I used a lot of the original ground points throughout the chassis, which probably doesn't help. But, it shows a lot of promise. It sounds every bit as good as my PP SV83 amp, and I feel the sound is more coherent and better detailed. It very punchy, and there is ALOT of power on tap. I can really crank it up, and it stays clean. I'll put the scope on it this weekend and see what it measures. Here's some pics of the amp: http://www.execpc.com/~n9zes/1625seamp.html It's not pretty, but it's a good test bed. Once I tweak it up, I'll build a proper chassis and make it look nice. I may even have a nice power tranny wound up for it, as the one now isn't the quietest. It hums and buzzes a little, but we can fix that. Well, that's about it. I'm pretty pleased with it so far, but the real test is when it is running the Edgarhorns. Then we will see how it really sounds. It will make a nice compact stereo amp to hold me over until I get around to building up a monster pair of monoblock SV572-3 or - -10 amps. I just don't have the room to fit that stuff right now. Thanks for the bandwidth! Chris http://www.execpc.com/~n9zes ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 1625 SE Ultralinear amp up and running! - long Date: Wed, 2 Feb 2000 22:01:39 EST Source: Sound Digest Archive v02.n432 In a message dated 2/2/00 7:49:11 PM US Mountain Standard Time, n9zes@execpc.com writes: > I'm pretty pleased with it so far, but Hey Chris, This is he life! No buts :) Happy Ears! Al B^} ========================================================================= From: "Ellen Oler" Subject: [JN] 1625 SE Ultralinear amp up and running! - long Date: Wed, 02 Feb 2000 22:24:11 -0500 Source: Sound Digest Archive v02.n432 >I had Jack at Electra-Print wind me up a pair of TM3KB trannies with 44% >UL taps, ordered up the parts, and went to work. Must be nice to have Jack at your "Beck" and call. Here's a second line so that mine isn't a "one-liner" post - I would hate to offend an obnoxious, non-contributing lurker now, wouldn't I? - -j ========================================================================= From: StepHydro@aol.com Subject: Re: [JN] 1626 class A, forgive the silly part :-) Date: Mon, 28 Feb 2000 08:47:11 EST Source: Sound Digest Archive v02.n468 Well, duuuh, I flipped over to Bob D's site and a couple of the schematics give the bias voltage and cathode resistor values. If Ohms law is turned on today :-), then 25-27 mA per valve. It would still be nice to have curves, etc. if anyone knows of a set in captivity. Cheers/Carron ========================================================================= From: "Gary E. Kaufman" Subject: RE: [JN] 1626 class A, forgive the silly part :-) Date: Mon, 28 Feb 2000 09:57:23 -0500 Source: Sound Digest Archive v02.n468 I have the curves for the 1626 extracted from the HB3 if anyone needs them. I can attach to an email off list (about 82Kb) - Gary EMAIL: gkaufman@the-planet.org Web: http://www.the-planet.org > -----Original Message----- > Subject: Re: [JN] 1626 class A, forgive the silly part :-) > It would still be nice to have curves, etc. if anyone knows of a set in > captivity. > > Cheers/Carron > ========================================================================= From: "gtrmkr" Subject: [JN] 1626 operating points Date: Mon, 22 Oct 2001 19:12:11 -0400 Source: Sound Digest Archive v02.n994 Paul, Gary -- Schematics are on the way, check your email. Dan -- RE: taking the output from the CT of the secondary -- great suggestion. I give it a try, thanks. IIRC, the 1626 has a "book" rp ~ 1.7K. Not nearly as low as the 6em7. I've tried that driver, BTW. Sounds very good. The rp of the 1626 probably isn't ideal for the little Allied, but I've also used that IT with 5687 and 5842 with decent results. I don't have test equipment so can't comment on the way it screws up the waveform, but it has sounded decent in a variety of applications. Some folks I know have also had good luck using a zobel on the secondary. Don't know the details, though. Jim ========================================================================= From: "Jon Lane" Subject: [JN] 1626 op points? Date: Sat, 20 Oct 2001 19:35:19 -0700 Source: Sound Digest Archive v02.n994 Anyone have a favorite operating point for the 1626 as IT-coupled driver? Data is scarce... TIA, Jon Lane ========================================================================= From: "gtrmkr" Subject: Re: [JN] 1626 op points? Date: Mon, 22 Oct 2001 10:17:27 -0400 Source: Sound Digest Archive v02.n994 On 20 Oct 2001, at 19:35, Jon Lane wrote: > Anyone have a favorite operating point for the 1626 as IT-coupled > driver? Data is scarce... > > TIA, > Jon Lane > Hi Jon, Haven't tried the 1626 as a driver, but as linestage, using bridged Allied IT (ala Dan Marshall) ~ 235 V B+, ~ 20 -22 ma (1K cathode R), "Ultrapath" connected, sounded very nice. Hope this helps. Jim ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 1626 op points? Date: Mon, 22 Oct 2001 10:20:47 -0400 Source: Sound Digest Archive v02.n994 here is some data: http://www.geocities.com/bobdanielak/rca1626.gif http://www.geocities.com/bobdanielak/1626.pdf http://www.geocities.com/bobdanielak/1626.gif i think anything under 250V on the plate is good. i think anything under 30mA thru the tube is good. for IT loading you might want to check out the "sakuma darling" down the middle of this page: http://www.geocities.com/bobdanielak/darling.html or schematic only: http://www.geocities.com/bobdanielak/sakumadarling.gif i started out with the IT stage identical to the output stage with a common 500 ohm cathode resistor. this would have meant that all 4 tubes would be operating at the standard "darling" output stage operating point of around Eb = 235V, Ec = -27V, Ib = 27mA i don't recall if i actually *heard* a problem with this arrangement, or if i just yeilded to the suggestion to keep the primary current below 20mA. but i wound up replacing the 500 ohm cathode resistor with 750 ohm. this brought the plate current down to about 20mA. it sounds pretty good. if your IT can handle 25mA or so, it might be better... only one way to find out. good luck, bob.d. > ---------- > From: Jon Lane[SMTP:jhlane@gs2designs.com] > Sent: Saturday, October 20, 2001 10:35 PM > To: Joenet > Subject: [JN] 1626 op points? > > Anyone have a favorite operating point for the 1626 as IT-coupled driver? > Data is scarce... > > TIA, > Jon Lane > ========================================================================= From: "gtrmkr" Subject: Re: [JN] 1626 op points? Date: Mon, 22 Oct 2001 11:50:36 -0400 Source: Sound Digest Archive v02.n994 On 22 Oct 2001, at 23:31, SHAMSUL Bahrin Kamarudin wrote: > Am interested in such a linestage using 1626 tubes, any chance u can > email me the schematics ? > > Regards. > > ::-) Sure. On the way ... two versions. Have fun. Jim ========================================================================= From: "gtrmkr" Subject: Re: [JN] 1626 op points? Date: Mon, 22 Oct 2001 22:46:05 -0400 Source: Sound Digest Archive v02.n994 On 23 Oct 2001, at 9:14, david tan wrote: > Hi Jim, > I was just thinking of a 1626 in a preamp a few days ago! Please send > me your schematics. Thanks David Tan On the way ... ========================================================================= From: Grover Gardner Subject: Re: [JN] 1626 Parafeed Line Preamp ? Date: Tue, 21 Sep 1999 15:10:11 -0400 Source: Sound Digest Archive v02.n282 At 4:18 PM +0800 9/21/99, SHAMSUL Bahrin Kamarudin wrote: >Hello. > >A just a wild thought, any possibilities of such a parafeed line preamp >design with them 1626 tubes ? > >Till later then, keep up the good work on them 1626 tube designs. I've tried a regular, resistance-loaded 1626 as a preamp, also with choke load. Used a tube-regulated supply. Not bad--a little coarse, but potent. I suspect the input capacitance is a bit high, causing some HF rolloff--or is this an issue when we're only demanding a few volts swing? Anyway, it was kinda fun, but I didn't stick with it. Maybe I'll give it another go at a later date. I'm prone to doing that...;-) Grover Gardner groverg@postoffice.att.net ========================================================================= From: SHAMSUL Bahrin Kamarudin Subject: [JN] 1626 Parafeed Line Preamp ? Date: Tue, 21 Sep 1999 16:18:03 +0800 Source: Sound Digest Archive v02.n282 Hello. A just a wild thought, any possibilities of such a parafeed line preamp design with them 1626 tubes ? Till later then, keep up the good work on them 1626 tube designs. Regards. ::-) _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ SHAMSUL Bahrin Kamarudin Head Of Department Information Technology Dept. INNOSABAH Securities Sdn Bhd 11 Equity House, Block K, Sadong Jaya, Karamunsing, 88100 Kota Kinabalu, Sabah, M A L A Y S I A. Tel: +60(88) 234099 ext. 8701 Fax: +60(88) 234100 mailto:shamsul.BK@innosabah.com.my http://www.innosabah.com.my _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 1626 Parafeed Line Preamp ? Date: Tue, 21 Sep 1999 17:47:05 -0400 Source: Sound Digest Archive v02.n283 > At 4:18 PM +0800 9/21/99, SHAMSUL Bahrin Kamarudin wrote: > >Hello. > > > >A just a wild thought, any possibilities of such a parafeed line preamp > >design with them 1626 tubes ? > > > i breadboarded a parafeed 1626 line-stage with a 36H/60mA choke, B+ = 265V, cathode resistor = 1K with 470uF bypass. basically a darling amp output stage with choke load instead of an OPT. used a 2uF output cap into a 100K output load. had some problems with the bench supply when checking it out so i never followed thru with this design. (since i really didn't think i needed a new line stage). there it sits on the shelf. maybe i'll fire it up after i get the D3.5 running. i have a working 1626 line stage (somewhere - i lent it out to a prospective buyer). that one uses the same power supply, but a 15K resistive load. sounds pretty good. it did wonders in front of big SS amps. interesting, though. on my amps, the line stage, or lack thereof, doesn't seem to affect the sound so much. in other systems, i've heard *vast* differenced by replacing the rectifier in the line stage....?!? grover added: > I've tried a regular, resistance-loaded 1626 as a preamp, also with choke > load. Used a tube-regulated supply. Not bad--a little coarse, but > potent. > I suspect the input capacitance is a bit high, causing some HF rolloff--or > is this an issue when we're only demanding a few volts swing? Anyway, it > was kinda fun, but I didn't stick with it. Maybe I'll give it another go > at a later date. I'm prone to doing that...;-) > the input capacitance of these tubes is pretty low as power triodes go. like 25pF, iirc. including miller effect. this is lower than a 417, 437, 6dj8, etc. it does have a higher output impedance, which may cause trouble down the line (cables, following stage, etc) that's more likely the roll-off problem. however, the output Z is still lower than a 26 or 56, which i hear make a very nice line stage. i am contemplating an 01-A line stage/driver, and i'm struggling with exactly this issue. 10K plate resistance.... hmmmm the 1626 would drop this to 1k or so. maybe i ought to just go back to the 1626.... bob.d. ========================================================================= From: SBench@aol.com Subject: Re: [JN] 1626 Parafeed Line Preamp ? Date: Tue, 21 Sep 1999 21:00:08 EDT Source: Sound Digest Archive v02.n283 In a message dated 99-09-21 18:06:20 EDT, robert.m.danielak@lmco.com writes: << i am contemplating an 01-A line stage/driver, and i'm struggling with exactly this issue. 10K plate resistance.... hmmmm the 1626 would drop this to 1k or so. maybe i ought to just go back to the 1626.... >> Hi Bob, But the 01A sounds sooooooooooo nice as a line stage ;-) Steve ========================================================================= From: StepHydro@aol.com Subject: [JN] 1626 plate curves, class A Date: Mon, 28 Feb 2000 08:39:08 EST Source: Sound Digest Archive v02.n468 Does anyone know a URL which lists plate characteristics/curves for the 1626 in Class A?? Know what current is used in the darlings? How about in Cl A PP Cheers/Don Carron ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 1626 plate curves, class A Date: Mon, 28 Feb 2000 10:26:04 -0500 Source: Sound Digest Archive v02.n468 the 1626 RCA data sheet re-print was published along with the original "hello darling" article in SP#15. i'm sure you all subscribe.... ;) you can check: http://www.geocities.com/bobdanielak/1626.gif for home-grown curves. hth, bob.d. > ---------- > From: StepHydro@aol.com[SMTP:StepHydro@aol.com] > Sent: Monday, February 28, 2000 8:39 AM > To: sound@lists.io.com > Subject: [JN] 1626 plate curves, class A > > Does anyone know a URL which lists plate characteristics/curves for the > 1626 > in Class A?? Know what current is used in the darlings? How about in Cl A > PP > > Cheers/Don Carron > ========================================================================= From: "Gary E. Kaufman" Subject: [JN] 1626's Date: Thu, 10 Jun 1999 20:29:55 -0400 Source: Sound Digest Archive v02.n175 Add me to the list of people putting together a DC-Darling. I'm about 2/3rds wired, and hope to see power next week. I'm using a set of trannies from a Heathkit AA-151 amp for my first try. Hopefully these relatively massive output trannies from the PP 6BQ5 amp will do well with the dc current. He're the fun part. I have an opportunity to purchase a LARGE (100-400) quantity of 1626's at a good price. Some of you have expressed concern that the 1626 supply may be dried up with all of this construction. If there were enough interest I'd be willing to grab a large pile and offer them to the group. I just don't want to be stuck with several hundred! So, would people be interested in getting say 8 tubes for $20 including priority mail shipping in the USA? They are NOS/NIB, but I won't be testing them before shipping. Feel free to email me privately so as to not clog the list. If there were enough interest I'll go ahead an pick up most or all of the pile. - Gary ========================================================================= From: "Gary E. Kaufman" Subject: [JN] 1626's Date: Thu, 10 Jun 1999 21:48:05 -0400 Source: Sound Digest Archive v02.n175 Thank you for your quick replies about the 1626's. Based on the initial swarm of email, there must be alot of soldering going on out there! I have seen enough interest to go ahead and take the plunge. I have committed to 200 tube (ouch) and will have an option on another 200 if necessary. There isn't much in this for me financially, it is mostly a way to pass a thank you along to the group for this great project. I'm better at scrounging parts than designing amps! I'll make sure I keep enough to take care of those I've heard from already, and will post back to the group when the tubes arrive. Please don't send checks at this point. Also, I'll send a complimentary package along to Bob Danielak as a special thanks for bringing this design public! - Gary ========================================================================= From: "Gary E. Kaufman" Subject: [JN] 1626's Date: Mon, 19 Jul 1999 16:12:59 -0400 Source: Sound Digest Archive v02.n207 I ran into another cute amplifier this weekend that also uses 1626's - A Heathkit A-4. Making the best of WWII Surplus it uses 3 1626's as input tubes and a pair of PP 12A6 outputs. I threw up a few photos, an early advertisement and a hand-drawn schematic on my website at http://www.the-planet.org if anyone is curious. - Gary ========================================================================= From: dslagle@earthlink.net (dave slagle) Subject: [JN] 1626's on ebay Date: Wed, 13 Oct 1999 17:29:12 -0400 Source: Sound Digest Archive v02.n301 hey all stumbled upon this... http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=177620150 no connection... just a bunch of 1626's (western electrics to boot :-) dave ========================================================================= From: "Henry Platt" Subject: [JN] 1626 supply Date: Tue, 21 Sep 1999 23:14:27 -0700 Source: Sound Digest Archive v02.n283 Joes, I think can get a big supply of NOS military branded 1626's. Will sell for about 3 bucks a pop. any interest? Cheers, Henry Platt ========================================================================= From: dslagle@earthlink.net (dave slagle) Subject: [JN] 1629-3=???? Date: Fri, 26 Feb 1999 09:24:48 -0500 Source: Sound Digest Archive v02.n064 >Eh? Isn't the 1629 a magic eye indicator tube? > >Why on earth use it as an amplifier?! > well, why not??? no offense intended... but I think we have way too many thoughts shot down before they are given a shot... and many more don't even get close to a fair shot... its an indicator tube... so what??? worst case scenario is someone builds with it and it gives a cool light show, but SUBJECTIVELY unpleasing sound.... lesson learned... but the finer points of another tube are learned... and maybe it could be implamented otherwise. I never thought of it... and have some... could be cool... if you get good sound and a light show to boot... more power to you... hell the light show and looks have driven me to a discovery or two... and I took some ridicule along the way... I'm glad I stuck with it... hell someone telling me something is not a good idea is reason enough to try it! please by all means build with this tube... and let us know what happens... hell even if it turns out to be a glorified power indicator light... that is still cool! dave... thinking about how crazy bob d was to use that "incredibly non-linear" "not fit for audio" 1626... based on... of all things... it looks cool! hey bob... if the 1629 is indeed similar to a 6SL7.... I noted it does take a 12.6V filament... and antique has them for DD$590... and they are just 3 numbers apart... isn't that darling???? that is what we are here for isn't it??? ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 1629-3=???? Date: Tue, 02 Mar 1999 09:52:08 -0500 Source: Sound Digest Archive v02.n065 > ---------- > From: dslagle@earthlink.net[SMTP:dslagle@earthlink.net] > Sent: Friday, February 26, 1999 9:24 AM > To: sound@deliverator.io.com > Subject: [JN] 1629-3=???? > > >Eh? Isn't the 1629 a magic eye indicator tube? > > > >Why on earth use it as an amplifier?! > > > > well, > > why not??? > > no offense intended... but I think we have way too many thoughts shot down > before they are given a shot... and many more don't even get close to a > fair shot... its an indicator tube... so what??? > > worst case scenario is someone builds with it and it gives a cool light > show, but SUBJECTIVELY unpleasing sound.... lesson learned... but the > finer > points of another tube are learned... and maybe it could be implamented > otherwise. > > I never thought of it... and have some... could be cool... if you get good > sound and a light show to boot... more power to you... > > hell the light show and looks have driven me to a discovery or two... and > I > took some ridicule along the way... I'm glad I stuck with it... hell > someone telling me something is not a good idea is reason enough to try > it! > > please by all means build with this tube... and let us know what > happens... > hell even if it turns out to be a glorified power indicator light... that > is still cool! > > dave... > > thinking about how crazy bob d was to use that "incredibly non-linear" > "not > fit for audio" 1626... based on... of all things... it looks cool! > funny, my wife's been calling me "crazy chester" cause all i've been playing lately is the Band's "to kingdom come" compilation...... well, asthetics are 50%, sound is another 50%, ....and what's the other 50%, yogi? > hey bob... if the 1629 is indeed similar to a 6SL7.... I noted it does > take a 12.6V filament... and antique has them for DD$590... > kinda rich for my blood...... ;) > and they are > just 3 numbers apart... isn't that darling???? > > wow, that's even closer than the 1634 i was thinking of. it's a *metal* tube, and the cathodes are already tied together for me..... ;) hey! you guys. put those rocks down ;) > that is what we are here for isn't it??? > i always thought so..... see you at nyNoise!!!! bob.d. ========================================================================= From: Paul Mouritsen Subject: [JN] 1629 Date: Fri, 18 Jun 1999 08:39:36 -0400 Source: Sound Digest Archive v02.n181 Hi, Couple of questions for the group. Last week I ordered four 1626's with the idea of making one of the "Darling" incarnations for my brother. AES sent me 3 1626's and one 1629. The boxes were all JAN and looked alike so I guess they just goofed. They were great about it and will be sending me the errant 1626 tubes. They said I should just keep the 1629. I looked it up and it is an indicator tube. Does anyone have any cool ideas for using this beast in an amp or preamp circuit or just some info on how to wire it? Maybe I will just wire it into my brothers amp so he can watch the indicator... :-) Next question is... I just put an 83 into my amp. I have been trying different rectifiers in this amp to see how they sound. I like the 83 the best so far. When it starts up in my LCRC circuit I get a blue flash at turn on. Is this arcing? If so should I consider putting a switch on the center tap of the B+ and switchiung it on separately? Thanks a lot for the help that many of you have offered over the past few weeks. The amp is sounding pretty good to me. It now exists as 5842/cap/371A with a plate choke on the 5842 and battery bias. The plate chokes are actually the primaries from my Lundahl interstages which I am still deciding on. They have an inductance of about 33H. Best, Paul Paul Mouritsen Network Analyst Holy Cross Hospital Silver Spring, Maryland mourip @ holycrosshealth.org ========================================================================= From: Paul Mouritsen Subject: [JN] 1629 Date: Fri, 18 Jun 1999 14:46:23 -0400 Source: Sound Digest Archive v02.n181 Hi, I seem to not see my own posts on the list. Could someone email me if this shows up. Sorry if it has shown twice.Thanks....mourip@holycrossheath.org > Couple of questions for the group. Last week I ordered four 1626's with the idea of making one of the "Darling" incarnations for my brother. AES sent me 3 1626's and one 1629. The boxes were all JAN and looked alike so I guess they just goofed. They were great about it and will be sending me the errant 1626 tubes. They said I should just keep the 1629. I looked it up and it is an indicator tube. Does anyone have any cool ideas for using this beast in an amp or preamp circuit or just some info on how to wire it? Maybe I will just wire it into my brothers amp so he can watch the indicator... :-) Next question is... I just put an 83 into my amp. I have been trying different rectifiers in this amp to see how they sound. I like the 83 the best so far. When it starts up in my LCRC circuit I get a blue flash at turn on. Is this arcing? If so should I consider putting a switch on the center tap of the B+ and switchiung it on separately? Thanks a lot for the help that many of you have offered over the past few weeks. The amp is sounding pretty good to me. It now exists as 5842/cap/371A with a plate choke on the 5842 and battery bias. The plate chokes are actually the primaries from my Lundahl interstages which I am still deciding on. They have an inductance of about 33H. Best, Paul Paul Mouritsen Network Analyst Holy Cross Hospital Silver Spring, Maryland mourip @ holycrosshealth.org ========================================================================= From: Roscoe Primrose Subject: Re: [JN] 1629 Date: Fri, 18 Jun 1999 15:06:28 -0400 Source: Sound Digest Archive v02.n181 Paul Mouritsen wrote: > > Hi, > > I seem to not see my own posts on the list. Could someone email me if this > shows up. Sorry if it has shown twice.Thanks....mourip@holycrossheath.org > > It did show up twice, at least here... > > Next question is... I just put an 83 into my amp. I have been trying > different rectifiers in this amp to see how they sound. I like the 83 the > best so far. When it starts up in my LCRC circuit I get a blue flash at > turn on. Is this arcing? If so should I consider putting a switch on the > center tap of the B+ and switchiung it on separately? > The 83 ( like all mercury rectifiers) needs to be heated for a time (at least 15 sec maybe?) before HV is applied, so you may even want to switch both sides of the B+ rather than the CT. Peace - -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter "640K ought to be enough for anybody" , Bill Gates, 1981 ========================================================================= From: "Chu, An-shyang" Subject: [JN] 17173 CT Brook choke Date: Tue, 30 Mar 1999 11:17:38 -0700 Source: Sound Digest Archive v02.n102 Hi, Sorry to get back to this topic again.... just find a post by Mike from last summer (responding to Doc'B Valve article about using the Brook as the grid choke in a 211 design??). In it he stated that the Brook choke is design for 50Hy with CT connected and 200 Hy (?) if it is connected end-to-end. I would though 100 Hy instead. I guess I need to call Mike...... hopper ========================================================================= From: "Phil Sieg" Subject: [JN] 1899 & castrati (off-topic) Date: Thu, 6 May 1999 21:21:45 -0400 Source: Sound Digest Archive v02.n137 Joes, Now that I have your attention with the header (and try not to cringe), some musical thoughts. Last Thursday, as we know, was Duke's 100th birthday - meaning that his birth year was 1899. After some reminiscing and wool-gathering, I remembered 4 others born in the penultimate year of the 19th century that had significant impact on 20th century culture. They are Hoagy Carmichael, Fred Astaire, James Cagney and Humphrey Bogart. Pretty impressive list, no? So it makes me wonder...it is the penultimate year (media aside) of the 20th century. Wouldn't be fantastic to know which babies born this year are going to have that kind of impact on the 21st century? Or will anyone born this year have that impact? You guys adding to your families this year take special note. As to the uncomfortable subject of castrati. I just finished listening to the countertenor David Daniels with the St Louis SO on my local public radio station. If you have not heard him - this is not your ordinary countertenor. No falsetto, no white and thin sound. A real foundation to the voice. Reminiscent of Marilyn Horne and Janet Baker. We are talking power and a true vibrato here. My wife (with a mischievous twinkle in her eye) remarked "This is what the castrati must have sounded like". Upon which, I retreated to my computer to send this missal. Apologize for the bandwith, but I thought this might have some interest. Phil ========================================================================= From: "Le Cleac'h J.-M." Subject: Re: [JN] 1899 & castrati (off-topic) Date: Fri, 7 May 1999 09:15:40 +0200 Source: Sound Digest Archive v02.n137 > De : Phil Sieg > A : Joe-Net > Objet : [JN] 1899 & castrati (off-topic) > Date : vendredi 7 mai 1999 03:21 > As to the uncomfortable subject of castrati. I just finished listening to > the countertenor David Daniels with the St Louis SO on my local public radio > station. If you have not heard him - this is not your ordinary > countertenor. No falsetto, no white and thin sound. A real foundation to > the voice. Reminiscent of Marilyn Horne and Janet Baker. We are talking > power and a true vibrato here. My wife (with a mischievous twinkle in her > eye) remarked "This is what the castrati must have sounded like". Upon > which, I retreated to my computer to send this missal. Hello, For you information, there is an interesting website on the subject of countertenors at: http://www.medieval.org/emfaq/performers/countertenors.html Best regards, Jean-Michel Le Cleac'h, Paris, France ========================================================================= From: torgd@tolstoy.lerc.nasa.gov (Russell DeAnna) Subject: 18" Sonotube Subwoofer Update Date: Tue, 19 Jan 1999 16:06:25 -0500 (EST) Source: Sound Digest Archive v02.n001 Finally, an update on my 18" Sonotube subwoofer. I haven't written about it since last summer. Anyway, with the on-line help of Greg Monford, I finished the pair of subs on Labor Day 1998. Brief description: 18" diameter by 8 feet long Sonotube. The drivers are from SCH (Speaker Clearing House), the 18" model. The drivers are mounted on a ring of MDF and just manage to fit inside the 18" Sonotube. (If I had to build another pair, I'd not try to fit an 18" driver into an 18" tube. I'd use a 24" tube or a 15" driver.) The driver is mounted at one end; the opposite end is sealed with 3/4" times 2 thick discs of MDF. The MDF pieces are attached to the cardboard Sonotube using at least 40 wood screws around the circumference (you need strong wrists to build this project). Caulk was used after the screws. There is a 12" diameter port by 18" long located near the end where the driver mounts. Since you can't put an 18"-long port in an 18" diameter tube, the port is mounted so half sticks out of the tube. I used a pair of "L" brackets (mounted on the inside of the tube) to hold the port in place. Caulk around the port to seal. The entire Sonotube is covered with a pale-yellow piece of fabric, glued to the Sonotube. The port is black, PVC pipe. I chose pale yellow as a neutral color which wouldn't show lint and dirt like black or white. (The color is close to that of a yellow 'stick em' pad.) Acoustic Design: I don't have the numbers in front of me, but the Vbox was 365 l, the fs was 30Hz. If anyone wants the details, let me know. Stuffing was Owens Corning Miraflex. Application: They don't have legs, so I tried standing them up with the drivers facing the ceiling. That looked very cool, but it put the driver 8 feet off the floor and more than 8 feet away from the woofer in my Cornwalls. So I laid the tubes down on their sides behind the Cornwalls. 8 feet is about right for my speaker separation, so the Sonotubes span the entire distance between (and behind) the main speakers. The tubes are stacked, one on top the other. 18 inches times 2 equals three feet, which puts them almost to the top of the Cornwalls. Subwoofer Amp: I'm using a circa '70s Marantz 40W receiver. (Believe me, the little receiver has more than enough power to shake the building.) Crossover: I built a 2nd-order low-pass (set at 100Hz) and a 1st-order high-pass (100Hz) into the output of my pre-amp. All crossovers built with R C components. Main Amp: home brew 6ck4 SE amp with Electroprint MTK5B opt's. Result: I don't know how I ever lived with vacuum-tube bass and don't believe anyone who tells me a small tube amp can drive a woofer or a subwoofer. (I tried driving the sub with the little 6ck4 SE amp and almost nothing happened.) Anyway, my neighbor calls about once a week to complain about the noise. (I live on the 2nd floor of a condo.) So I feel like the owner of a Ferrari driving in rush-hour traffic.) I used the Stereophile test CD and got significant output at 25 Hz and not much at 20 Hz. But 25 Hz is enough for music, and I'm very, very happy with the result. A subwoofer driven by a SS amp makes every CD in my collection a new experience. Only my neighbor hates me now. - -Russell ========================================================================= From: STEVE CORNETT Subject: 18" Sonotube Subwoofer Update Date: Wed, 20 Jan 1999 08:53:21 -0600 Source: Sound Digest Archive v02.n003 Russell posted: "...A subwoofer driven by a SS amp makes every CD in my collection a new experience. Only my neighbor hates me now..." A small price to pay ;-) Steve C. ========================================================================= From: Roscoe Primrose Subject: [JN] 192/24 digital input receiver? Date: Tue, 24 Aug 1999 09:20:35 -0400 Source: Sound Digest Archive v02.n261 Anyone know if there's one available off the shelf yet? Peace - -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter "640K ought to be enough for anybody" , Bill Gates, 1981 ========================================================================= From: David Dlugos Subject: Re: [JN] 1952 Jensen Backloaded Horn design Date: Thu, 28 Jun 2001 10:07:07 -0700 Source: Sound Digest Archive v02.n916 Rick, I went in and fixed the names [made them a little shorter]: (some browsers believe what the server tells them and can't easily show these pictures other than a long stream of seemingly random text) >http://joelist.free.fr/public/JensenBackLoadHornImage.jpg >http://joelist.free.fr/public/JensenBackLoadHorn_Drawing.jpg >http://joelist.free.fr/public/JensenBackLoadHorn_1_LowRes.jpg dave ____________________________________ Transmission Line Speaker Page http://www.t-linespeakers.org/ new -- Martin King's ML TQWT ========================================================================= From: Rick Francis Subject: [JN] 1952 Jensen Backloaded Horn design Date: Thu, 28 Jun 2001 10:35:44 -0400 Source: Sound Digest Archive v02.n916 Joes, Here's an image of the original design of the horns I recently acquired and raved about: http://joelist.free.fr/public/JensenBackLoadedHornImage.jpg The plans and more information can be found at: http://joelist.free.fr/public/JensenBackLoadedHorn_Drawing.jp http://joelist.free.fr/public/JensenBackLoadedHorn_1_LowRes.j Yes, those are truncated URLs for jpg's, but that's how they got translated in the move to the new free site, and they work. (Thanks to Pierre-Frédéric Caillaud for setting up that site!) As indicated, the original plans called for a 15" driver with optional tweeter mounted across the 15". The fellow who built the pair I have instead mounted a tweeter just below the 15" driver, where the plans & image show crossover controls. In addition, on mine a 12" driver is mounted on the downward-facing slope of the horn mouth. I'd be interested in any comments, experiences, whatever. You can tell me why they probably suck, because I'm having too much fun with them to get upset about it. I will get around to figuring out what kind of crossover and drivers they have, and for the heck of it will try using some horn-loaded ribbon tweeters (Mark Rauen-designed and -built) on top of them -- but will have a hell of a time getting the drivers in the same vertical plane. Rick ========================================================================= From: Rick Francis Subject: Re: [JN] 1952 Jensen Backloaded Horn design Date: Thu, 28 Jun 2001 14:27:02 -0400 Source: Sound Digest Archive v02.n916 Thanks, Dave! I should have done that myself... but I only tested them by pasting in the URLs in IE, where they *did* work. Only after the message posted I found that clicking to open them in Netscape did NOT work... and then it was lunchtime. : ) OH -- two of the 10H 250ma chokes are sold. The third one is available for $15. - --Rick David Dlugos wrote: > Rick, > > I went in and fixed the names [made them a little shorter]: > (some browsers believe what the server tells them and can't easily show > these pictures other than a long stream of seemingly random text) > > >http://joelist.free.fr/public/JensenBackLoadHornImage.jpg > > >http://joelist.free.fr/public/JensenBackLoadHorn_Drawing.jpg > >http://joelist.free.fr/public/JensenBackLoadHorn_1_LowRes.jpg > > dave > > ____________________________________ > > Transmission Line Speaker Page > > http://www.t-linespeakers.org/ > > new -- Martin King's ML TQWT ========================================================================= From: David Dlugos Subject: Re: [JN] 1976? Date: Sun, 9 Jan 2000 17:16:50 -0800 Source: Sound Digest Archive v02.n393 >What were YOU using to listen to music in 1976? A lot of churn that year. What i can remember... Homebuilt TLs, Jordan Watts, Lowther Acoustas (PM6A), LS3/5a HK Citation 11/12, Quad 33/303, Quad 22/IIs, ST-70, SCA35 AR TT, Ariston, my 1st Linn LP12 (w Grace 707) dave _____________________________________________________ "Live music is better, bumper stickers should be issued" Neil Young ========================================================================= From: Ishmael349@aol.com Subject: Re: [JN] 1976? Date: Sun, 9 Jan 2000 19:31:10 EST Source: Sound Digest Archive v02.n393 So . . . don't think the ST-70/Advents was good enough for you? What were YOU using to listen to music in 1976? Had you tried the Marantz Model-9? Or the 8B? The 1 or the 2? How about the Quad II? Had you owned original Quads? Or Time-Windows? The Met Ones? Or DQ-10s? Maybe Electron Kinetics? Eagle One? Haffler? Ampzilla? Stax electrostatics? Fisher 500? By 1980, Neil Levenson and Bob Fulton were already listening to triodes -- push-pull 2A3s to be exact. What about you? ========================================================================= From: "David B. Klein" Subject: Re: [JN] 1976? Date: Sun, 09 Jan 2000 19:51:26 Source: Sound Digest Archive v02.n393 At 07:31 PM 1/9/00 EST, Ishmael349@aol.com wrote: >So . . . don't think the ST-70/Advents was good enough for you? What were >YOU using to listen to music in 1976? Had you tried the Marantz Model-9? Or >the 8B? The 1 or the 2? How about the Quad II? Had you owned original >Quads? Or Time-Windows? The Met Ones? Or DQ-10s? Maybe Electron Kinetics? >Eagle One? Haffler? Ampzilla? Stax electrostatics? Fisher 500? By 1980, >Neil Levenson and Bob Fulton were already listening to triodes -- push-pull >2A3s to be exact. What about you? > Who, me? ========================================================================= From: irishtom@webtv.net (tom brennan) Subject: Re: [JN] 1976? Date: Sun, 9 Jan 2000 20:01:44 -0600 (CST) Source: Sound Digest Archive v02.n393 Dynaco 400 and PAT-5, Klipsch LaScalas, Thorens 165, ADC-XLM Tom Brennan http://community.webtv.net/irishtom/TommysHornSpeaker ========================================================================= From: "Fred Volz" Subject: Re: [JN] 1976? Date: Sun, 9 Jan 2000 22:38:18 -0500 Source: Sound Digest Archive v02.n393 Hi: I'm confused. Is all of this stuff below directed to me, or someone else? Just for the record, I said that the Stereo 70/Advent combo described below is good for people who like MUSIC. And, I like music. However, if you want to know what I was listening to in 1976, hear goes. Dual 1019 with sonus Blue (or, perhaps, that transparent red Dynavector MC--can't remember). Home brew interconnects made from some Teflon insulated and jacketed coax. Home brew preamp built in a PAS3X box. Home brew PP VT-52 amp built on Dynaco ST-70 chassis, using ST-70 iron. Around this time, we started building a PP 845 amp, but we didn't finish it until 5 years ago. Speaker cables were of many strands of woven white and brown copper wires--don't know the brand. Speakers were Dynaco two way box--don't remember the model. Sorry I can't remember all of the details of this system: I was eleven and it was my dad's. Oh, one other thing. He had these great headphones (big square white things). They may have been Warfdale. They were really nice. Best wishes, Fred Volz fcv@emotiveaudio.com - -----Original Message----- From: Ishmael349@aol.com To: fcv@emotiveaudio.com ; sound@io.com Date: Sunday, January 09, 2000 7:32 PM Subject: Re: [JN] 1976? >So . . . don't think the ST-70/Advents was good enough for you? What were >YOU using to listen to music in 1976? Had you tried the Marantz Model-9? Or >the 8B? The 1 or the 2? How about the Quad II? Had you owned original >Quads? Or Time-Windows? The Met Ones? Or DQ-10s? Maybe Electron Kinetics? >Eagle One? Haffler? Ampzilla? Stax electrostatics? Fisher 500? By 1980, >Neil Levenson and Bob Fulton were already listening to triodes -- push-pull >2A3s to be exact. What about you? ========================================================================= From: David Lawrence Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 09:49:54 +0000 Source: Sound Digest Archive v02.n393 >>What were YOU using to listen to music in 1976? > >Technics SL-1100 with Sonus Blue, Dynaco PAT5, Dynaco Stereo 150 and HK Citation 12 Deluxe, IMF Super Compacts David ========================================================================= From: "spaaaz" Subject: RE: [JN] 1976? Date: Mon, 10 Jan 2000 19:44:56 -0600 Source: Sound Digest Archive v02.n393 youll have to forgive david he is allways negative.he has been listening to some cheap sand amps. Mr Spaaaz - -----Original Message----- From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On Behalf Of David B. Klein Sent: Sunday, January 09, 2000 7:51 PM To: Ishmael349@aol.com; fcv@emotiveaudio.com; sound@io.com Subject: Re: [JN] 1976? At 07:31 PM 1/9/00 EST, Ishmael349@aol.com wrote: >So . . . don't think the ST-70/Advents was good enough for you? What were >YOU using to listen to music in 1976? Had you tried the Marantz Model-9? Or >the 8B? The 1 or the 2? How about the Quad II? Had you owned original >Quads? Or Time-Windows? The Met Ones? Or DQ-10s? Maybe Electron Kinetics? >Eagle One? Haffler? Ampzilla? Stax electrostatics? Fisher 500? By 1980, >Neil Levenson and Bob Fulton were already listening to triodes -- push-pull >2A3s to be exact. What about you? > Who, me? ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 01:56:00 EST Source: Sound Digest Archive v02.n394 > >>What were YOU using to listen to music in 1976? Ears. Happy :) AR TT, Stanton 500E, Sherwood sand 20W rcvr, Rectilinear speakers. Lots more live music than records. We had season tickets to Minnesota Orchestra, St. Paul Chamber Orchestra, and were attending lots of student recitals at the U of M. And lots of guitar bands at the Union Bar. Dance to the music! Happy Ears! Al B^} ========================================================================= From: Thomas Danley Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 08:29:56 -0500 Source: Sound Digest Archive v02.n394 TubeGarden@aol.com wrote: > > >>What were YOU using to listen to music in 1976? > Hi all I lived in a house with a couple other guys, I had been building speaker cabinets for a living (fun but not profitable) for 3 years at that point. In my room I had a pair of very beat up, home made Voice of the Theater cabinets (511 horns on top), also had a pair of home made 20 foot transmission lines with what was at the time a long excursion 12" woofer in each, 15 RTR ESS panels and 3, 6" mid drivers in each. I also had my bass guitar box which was a 2X2X4 foot "W" bin I made to play through. This was a disaster sort of, I got the 4, 12's that went in it for free and made the box out of particle board (a precursor to mdf) to save money. Let me tell you, this was a heavy box and after the black latex paint got worn, it was very ugly also. One night the band was playing at a big college dorm party in the basement. It was no problem getting a bunch of the college guys to get the thing down the long flight of stairs and up on the riser. Our band had a ritual which involved sitting in a van and breathing a lot of "smoke", after "getting ready" this way, we go in to play and find that the people there enjoy the same ritual as well as lots of beer.. All was well, we did a nice job playing and the thick atmosphere made it unnecessary to re-visit the van until 2nd break when the drummer said he was getting tired. It got to be about 3 am when we quit playing, I was sooo tired, I looked around at the sea of bodies, some still moving and thought of getting the bass bin up the stairs. Then it hit me, a flash of brilliance, I turned to one of the "groupie" types that hung around the band and asked " hey, you want that bass bin?", Oh yeah cool he said, "its yours, see ya later". I grabbed the head and guitar case and trudged up the stairs, at the top I looked back at the box and thought, "man you are one heavy and ugly box, glad to be rid of ya" and that was the last I saw of it. I did hear much later that the groupie and friends went back and busted the box apart to get the drivers out and in the same sense of responsibility, snuck out and left the debris. For power I had a Mac 240, a pair of modified Mac M-60's and a pair of home built 200W tube amps (4X6550 ea.) for bass. Home made electronic crossover, Mac mx110 pre amp/tuner, Panasonic RS-736 reel to reel tape deck and one of several turntables (which have sort of blurred together), going through the Garrard, dual's a rabco, I know I had a very nice Perpetnum Ebner TT at one point, I would mind finding one of those again but I have never even heard of anyone else that knew what they were. I started building a turn table but never finished. Nearly everything was modified or had been worked on (as nearly all the electronic stuff was going to the dumpster at work or was home made). Would I go back? Hell no, I wouldn't mind he chance to go back in time to bring a few select things forward but I would never trade old speakers for what can be done now. Tom Danley ServoDrive inc. / Sound Physics Labs ========================================================================= From: Roscoe Primrose Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 09:36:23 -0500 Source: Sound Digest Archive v02.n394 TubeGarden@aol.com wrote: > > > >>What were YOU using to listen to music in 1976? > EICO ST-40, EICO mono fm tuner, Rek-O-Kut K-33 turntable, probably a pickering Cart, but I can't remember, some cheap cassette deck, home-made single driver full-range speakers. Music, mostly rock at the time... Peace - -- Roscoe Primrose -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter "640K ought to be enough for anybody" , Bill Gates, 1981 ========================================================================= From: "jhlane" Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 11:43:37 -0800 Source: Sound Digest Archive v02.n394 > > > >>What were YOU using to listen to music in 1976? Actually, around '80...Amber separates, Thorens TD160 with SME II, Sonus Blue Gold, home brew Jordan modules with (82dB!) Audax 5" Bextrene mid woofers. Then I heard a maxed VOT (with 604 in place of the woofers and a field coil mid on the horn) with triamped little SE WE tubes and WE iron. ZNFB pre using 6SN7 and 6SL7 with hi-perm tranny output. ET linear arm, Grado Sig., and a home brew 'table I had made a 12" x 3" acrylic platter for. And that, as they say, was that. JL ========================================================================= From: Ed Faulkner Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 12:14:53 -0800 Source: Sound Digest Archive v02.n394 > >> > >>What were YOU using to listen to music in 1976? >> I was 15 and purchased my first stereo. Large Advents and a Fisher receiver :-) _____________________________ Ed Faulkner \ through a child's eyes CMT Supervisor \ sky is blue Washington State University \ grass is green Pullman, WA,99164 \ I want to see again (509) 335-7566 \ efaulkne@wsu.edu \______________________ ========================================================================= From: David Barnett Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 12:46:56 -0600 Source: Sound Digest Archive v02.n394 On Sun, 9 Jan 2000 22:38:18 -0500, "Fred Volz" wrote: >Oh, one other thing. He had these great headphones (big square white >things). They may have been Warfdale. They were really nice. Sounds like a description of the Jecklin Float electrostatic headphones. - --dnb ========================================================================= From: Tim Reese Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 13:34:31 -0500 (EST) Source: Sound Digest Archive v02.n394 TubeGarden@aol.com wrote: > > >>What were YOU using to listen to music in 1976? > Let's see ... Yamaha CA1000 integrated amp, Yamaha CT400 Tuner, Technics SL-20 turntable w/ Ortofon MC cartridge and stepup transformer (don't remember the models) and Sonab speakers (again, the model number escapes me). Way before my revelation. BTW my brother still uses the Sonabs and really likes them, and I recently gave the Yamaha pieces away to a collegue here at the NMR Center ... he thought they were a big improvement over the almost-class-B Japanese transistor amp he was using. He runs the CA1000 with the "Class A" switch on all the time, limiting the amp to about 15W/ch. Back to the present ... tr - ---------------------------------------------------------------------- Visit http://www.nmr.mgh.harvard.edu/~reese MRI, tube audio, reptiles Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu ========================================================================= From: Rick Francis Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 14:48:45 -0500 Source: Sound Digest Archive v02.n394 At 01:34 PM 1/10/00 -0500, Tim Reese wrote: >TubeGarden@aol.com wrote: > >> > >>What were YOU using to listen to music in 1976? >> >Let's see ... Yamaha CA1000 integrated amp, Yamaha CT400 Tuner, Technics >SL-20 turntable w/ Ortofon MC cartridge and stepup transformer (don't >remember the models) and Sonab speakers (again, the model number escapes >me). > YEAH! You made the same mistakes *I* did! In 1977 I had a Yamaha CA-1000 (which I still own, sort of -- it's been loaned out for two years, and the guy LIKES it), Sonab OA-14's (buried in the basement -- I thought I might try them as rear HT speaks), and a Thorens TD-145 (also awaiting resurrection). No tubes for me back then... Rick ========================================================================= From: David Barnett Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 15:08:55 -0600 Source: Sound Digest Archive v02.n395 On Sun, 9 Jan 2000 19:31:10 EST, Ishmael349@aol.com wrote: >What were >YOU using to listen to music in 1976? As long as we're all trotting out the skeletons in our closets, I had a pair of Dynaco A25XL speakers, a Dynaco SCA-80Q integrated amp (I learned how to solder by assembling that kit), a Viking 76 tube reel-to-reel, and the dreaded Philips GA-212 turntable with some sort of B&O cartridge. Then I built a bunch of LS3/5A clones and other KEF-based things. Got my first Stereo-70 and PAS2 in 1980, and a pair of QUAD ESLs in 1981 (purchased from sometime Joelist member Scott Nixon...). I still have the QUADs, and that SCA-80Q has come back to haunt me too. - --dnb ========================================================================= From: William Eckle Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 15:35:16 -0700 Source: Sound Digest Archive v02.n395 On Sun, 9 Jan 2000 19:31:10 EST, Ishmael349@aol.com wrote: > >>What were >>YOU using to listen to music in 1976? I had 4) Altec A7s in a 4 channel arrangement driven by a Dynaco SQA 300 4 channel amp from a Tec hnics SU9070 preamp. A Technics SL110A turntable & arm, Shure cartridge (forget the model #, but was top of the line), Dynaco FM5 tuner and a Sony TC388-4, 4 channel tape deck, and an Audionics "Space & Image Composer", which decoded SQ and other stereo material into 4 channel. Used to tape bar bands in 4 channel on the tape deck. The musicians were usually knocked out hear ing themselves on the system. The Audionics decoder out preformed all versions of Dolby till the present AC3, and is still in u se for movies. ffff,0000,0000-=Bill Eckle=- wmeckle@uswest.net 0000,0000,ffffPhoenix, Arizona USA ========================================================================= From: "Henry Platt" Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 17:01:02 -0800 Source: Sound Digest Archive v02.n395 Yo. 1976 was the year that my Dyna SCA35 Blew up. You could still go down to North Philly and get replacement PC boards, which I did. It blew up again. (I never could solder too good back in them days) . I tossed it for a sandbox, until an MC240 winked at me from the curbside in Cambridge, Mass. It was the beginning of a long affair, which ended when I built my first SE one eyed triode amp. Sold the 240 to buy some glass and iron. Henry ========================================================================= From: "Fred Volz" Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 17:49:38 -0500 Source: Sound Digest Archive v02.n395 >> >> Sounds like a description of the Jecklin Float electrostatic >> headphones. > >Sounds more like the Wharfedale Isodynamics. These were like Magneplanars in >miniature, worked on the same principle. Very inefficient - connected directly >to the speaker terminals without dropper resistors - but very clean sounding. >Unfortunately, not very comfortable for long term use. That's it. They were planar in design and really needed to be pushed. We still have these. I'm sure that there are better headphones out there: I don't ever use headphones anymore. But, these things were very transparent. Thanks for the info! Fred Volz fcv@emotiveaudio.com > > >Lance > > ========================================================================= From: Nicholas McKinney Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 19:26:12 -0500 Source: Sound Digest Archive v02.n395 At 10:35 PM 1/10/00 +0300, Kurt Steffensen wrote: >Thomas Danley wrote: >> Our band had a ritual which involved sitting in a van and breathing a lot of >> "smoke", after "getting ready" this way, we go in to play and find that the >> people there enjoy the same ritual as well as lots of beer.. > >Ah , yes , those were the days....;-) Were? Oops, forget I said that............ >(I just wonder why Nick is sending me big soft sock , hearing aids and >brochures of >artifical teeths.....:-( > >- Heck , am I the only GrandPa' Joe ?? No, but at the moment you are the best to crack Grandpa jokes about I am afraid. In 1976 I was listening to old calypso records on my portable GE record player that I learned to operate in 1971. Imagine a mom seeing her kid work the turntable before learning how to walk, even took film of it........ What a patient woman, I am here making a CD transfer, removing many clicks and pops that - I - created 28 years ago. Oh well, anyone have any clean Merrymen pressings they want to send my way? Nick Nicholas McKinney Lambda Acoustics Inc. www.lambdacoustics.com www.onelist.com/community/LambdaDrivers ========================================================================= From: "Paul de Raymond Leclercq" Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 20:21:21 -0000 Source: Sound Digest Archive v02.n395 Crikey! Garrard 401/Decca International/C4E; Leak 70 (Yuk) and a pair of home made transmission lines to Dr Bailey's design. By 1978 this was changed to Grade G2+, Cambridge P50 and AR 2AX Paul - ----- Original Message ----- From: Tim Reese To: Sent: Monday, January 10, 2000 6:34 PM Subject: Re: [JN] 1976? > TubeGarden@aol.com wrote: > > > > >>What were YOU using to listen to music in 1976? > > > > Let's see ... Yamaha CA1000 integrated amp, Yamaha CT400 Tuner, Technics > SL-20 turntable w/ Ortofon MC cartridge and stepup transformer (don't > remember the models) and Sonab speakers (again, the model number escapes > me). > > Way before my revelation. > > BTW my brother still uses the Sonabs and really likes them, and I recently > gave the Yamaha pieces away to a collegue here at the NMR Center ... he > thought they were a big improvement over the almost-class-B Japanese > transistor amp he was using. He runs the CA1000 with the "Class A" switch > on all the time, limiting the amp to about 15W/ch. > > Back to the present ... tr > ---------------------------------------------------------------------- > Visit http://www.nmr.mgh.harvard.edu/~reese MRI, tube audio, reptiles > Tim Reese, MGH NMR Center reese@nmr.MGH.harvard.edu > ========================================================================= From: Lance Dow Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 21:38:51 +0000 Source: Sound Digest Archive v02.n395 David Barnett wrote: > > On Sun, 9 Jan 2000 22:38:18 -0500, "Fred Volz" > wrote: > > >Oh, one other thing. He had these great headphones (big square white > >things). They may have been Warfdale. They were really nice. > > Sounds like a description of the Jecklin Float electrostatic > headphones. Sounds more like the Wharfedale Isodynamics. These were like Magneplanars in miniature, worked on the same principle. Very inefficient - connected directly to the speaker terminals without dropper resistors - but very clean sounding. Unfortunately, not very comfortable for long term use. Lance ========================================================================= From: Kurt Steffensen Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 22:35:43 +0300 Source: Sound Digest Archive v02.n395 Thomas Danley wrote: > I lived in a house with a couple other guys, I had been building speaker > cabinets for a living (fun but not profitable) for 3 years at that point. Very-very similar to me , I think the western world shared the same values at that time.... - - Well , the young generation , that is :-) > In my > room I had a pair of very beat up, home made Voice of the Theater cabinets (511 > horns on top), also had a pair of home made 20 foot transmission lines with what > was at the time a long excursion 12" woofer in each, 15 RTR ESS panels and 3, > 6" mid drivers in each. Me to. 15" and a big top horn. (Sounded like shit on the HiFi....But LOUD :-) > I also had my bass guitar box which was a 2X2X4 foot "W" bin I made to play > through. Tha bass player of our house , had a Fender (+ more ) and a Ampeg , with 4 x 10" , in a funny "opposite" pyramid figure.....Sounded WONDERFULL....... ' Course the air we breathed those days helped a lot of that...... > This was a disaster sort of, I got the 4, 12's that went in it for free and made > the box out of particle board (a precursor to mdf) to save money. > Let me tell you, this was a heavy box and after the black latex paint got worn, > it was very ugly also. Big n' ugly speakers.. Wasn't that the standard then ? :-) > One night the band was playing at a big college dorm party in the basement. It > was no problem getting a bunch of the college guys to get the thing down the > long flight of stairs and up on the riser. Ohh... I freighten the home travel.... > Our band had a ritual which involved sitting in a van and breathing a lot of > "smoke", after "getting ready" this way, we go in to play and find that the > people there enjoy the same ritual as well as lots of beer.. Ah , yes , those were the days....;-) > All was well, we > did a nice job playing and the thick atmosphere made it unnecessary to re-visit > the van Haaaa :-) > - until 2nd break when the drummer said he was getting tired. Yeah , people seemed to get sudden tired then... > It got to be about 3 am when we quit playing, I was sooo tired, I looked around > at the sea of bodies, some still moving and thought of getting the bass bin up > the stairs. Then it hit me, a flash of brilliance, I turned to one of the > "groupie" types that hung around the band and asked " hey, you want that bass > bin?", Oh yeah cool he said, "its yours, see ya later". I grabbed the head and > guitar case and trudged up the stairs, at the top I looked back at the box and > thought, "man you are one heavy and ugly box, glad to be rid of ya" and that was > the last I saw of it. HA - ha--- Smashing idea... Easy come , easy go... > I did hear much later that the groupie and friends went back and busted the box > apart to get the drivers out and in the same sense of responsibility, snuck out > and left the debris. Ah , they caught the idea as well....... > For power I had a Mac 240, a pair of modified Mac M-60's and a pair of home > built 200W tube amps (4X6550 ea.) for bass. For the bass guitar ? - Real cool..... > Home made electronic crossover, Mac > mx110 pre amp/tuner, You should have kept that tuner.. I have never heard their pre-amp. > Panasonic RS-736 reel to reel tape deck and one of several > turntables (which have sort of blurred together), going through the Garrard, > dual's a rabco, I know I had a very nice Perpetnum Ebner TT at one point, Never heard of it.... > Nearly everything was modified or had been worked on (as nearly all the > electronic stuff was going to the dumpster at work or was home made). Echo echo....:-) > Would I go back? Hell no, I wouldn't mind he chance to go back in time to bring > a few select things forward but I would never trade old speakers for what can be > done now. Said the man behind servodrive...:-) - - Would I go back ? Hell yes... A couple of weeks a year , would be all healthy to me..... And I knew exactly what stuff to bring forward :-) I was building so many weird and far out speakers in the 1970's....(None of them worth bringing back ) And I had my first experiences with real good sounding HiFi... I remember , that I just the other day , in my happy new years joy , stated that the best thing for a long time , was the Joelist. - - That's not entirely true.... I mean - I have becomed a grandfather lately , my son has started school and other good stuff , that not even 100 Joelists can compete with...:-) But in my HiFi life , Joe list and all this internet buisness , compares very good to the best HiFi events in the 1970's. Several persons that I have met here , have had a great impact on my everyday life , and most certainly my audio life. At the very last day , in the 21' th century , Thomas Danley announced his new speaker to me , and told me I was going to recieve a pair. Now , would anyone blame me , that I praised the Joelist in high tones....? I have also made an agreement with big Nick , about representing the Lambda Acoustic drivers over here in the old land. No wonder I love the Joes :-) (I just wonder why Nick is sending me big soft sock , hearing aids and brochures of artifical teeths.....:-( - - Heck , am I the only GrandPa' Joe ?? Thanks ALL Joes , for the good, good discussions and interesting knowledge , that is revealed on this list. I promise , that in the year 2000 , I will present to the Joes and other interested parties , the best amplifiers on earth... You have to admit , that only two persons on this list , is so shamefully none modest , to claim such. - - I - the Grandpapa Joe , and him - the ThunderStone Joe... (I mean even Happy Al , only claim his amps to be the best in Texas....right ;-) - - Kurt ========================================================================= From: Gerhard Dierkes Subject: [JN] Re: 1976? Date: Tue, 11 Jan 2000 08:50:35 +0100 Source: Sound Digest Archive v02.n395 On Sun, 9 Jan 2000 19:31:10 EST, Ishmael349@aol.com wrote: >What were >YOU using to listen to music in 1976? Philips 2x30W class A amplifier, Klein + Hummel TX2 2-way speakers, Kirksaeter tuner, Uher Variocord 263 tape recorder, Philips turntable and Ortofon MC cartrige (I don't know which it was). In the back I had two fullrange speakers made of one piece styropor to get ambiophonic sound. Gerhard from Berlin ========================================================================= From: Ross J Lahlum Subject: Re: [JN] 1976? Date: Mon, 10 Jan 2000 22:23:36 -0600 Source: Sound Digest Archive v02.n396 Wow, 1976... I thought I had a pretty hot setup - Crown IC-150A, two Crown D60's strapped for mono, Dual 1229 with a Shure V15, Wharfedale W60E's, and coolest of all, a Teac 3340S. Still have the Teac, the Wharfedales are now my workshop speakers, sold the Dual and wish I hadn't so I could have something to play 78's on, sold the Crown IC150A when I was strapped for cash, kept the two D60's, one of which drives two RatShack Linaeums on the kids' computer. - -Ross On Mon, 10 Jan 2000 14:48:45 -0500 Rick Francis writes: > At 01:34 PM 1/10/00 -0500, Tim Reese wrote: > >TubeGarden@aol.com wrote: > > > >> > >>What were YOU using to listen to music in 1976? > >> > >Let's see ... Yamaha CA1000 integrated amp, Yamaha CT400 Tuner, > Technics > >SL-20 turntable w/ Ortofon MC cartridge and stepup transformer > (don't > >remember the models) and Sonab speakers (again, the model number > escapes > >me). > > > YEAH! You made the same mistakes *I* did! In 1977 I had a Yamaha > CA-1000 > (which I still own, sort of -- it's been loaned out for two years, > and the > guy LIKES it), Sonab OA-14's (buried in the basement -- I thought I > might > try them as rear HT speaks), and a Thorens TD-145 (also awaiting > resurrection). No tubes for me back then... > > Rick > ________________________________________________________________ YOU'RE PAYING TOO MUCH FOR THE INTERNET! Juno now offers FREE Internet Access! Try it today - there's no risk! For your FREE software, visit: http://dl.www.juno.com/get/tagj. ========================================================================= From: Harry Phillip Ferguson Subject: Re: [JN] 1976? Date: Tue, 11 Jan 2000 07:42:55 -0600 Source: Sound Digest Archive v02.n396 1976 wow just finished high school and spent the summer working and planning to go to junior college. I decided to get into Audio my system was fairly simple. Two pair of Advents stacked with tweeters one on top of each other Phase Linear 200 Amp Phase Linear 2000 Pre-Amp Fisher reciver used as a tuner Rabco ST-8 turntable Audio Techniques Cartriged This system really rocked it had great Bass and the midrange was fairly good it was great in college for thoose house parties, it could really thump and as long as you kept the PL-200 cool it would play all night. Harry ========================================================================= From: "John Sherwood, W4DRJ" Subject: Re: [JN] 1976? Date: Tue, 11 Jan 2000 08:12:28 -0800 Source: Sound Digest Archive v02.n396 1976 ??? Same gear as in 1966 ST-70, Pas-3x, FM-3, Benjamin Miracord (ELAC)TT AR-2ax speakers I built these kits in 1966 in the baracks (USAF, Keesler AFB, Miss) while I was an instructor in the electronics school there. Pretty soon I was getting requests to build for the other fellas in the barracks. Must have built half a dozen of each kit. I would charge the rediculous sum of $25 per k it to build 'em. (Attention, before you ask, we have increased our prices slightly) We had a surprise inspection one day and the squadron commander, a music lover, studied all the gear and then went through my entire record collection. His comment was, "I don't understand .... it's all classical and bluegrass ?" I replied, "Sir, bluegrass IS chamber music.... string quartets/quin tets". Did you ever notice this phenomena (it was phenominal to me anyway) ? .......... I noticed that in t he big cinderblock building in which I resided, a clean system would still sound pretty coherent whe n you got two or three foors away from it.... but a mildly distorted system really fell apart into u nrecognizable grunge at the same distance ? john, W4DRJ - --- e-mail to: sparkgap@mindspring.com HotBot - Search smarter. http://www.hotbot.com ========================================================================= From: Dan Kerl Subject: Re: [JN] 1976? Date: Tue, 11 Jan 2000 09:17:48 -0600 Source: Sound Digest Archive v02.n396 With co-op money (the most spendable money I ever had): SWTPC preamp (trick pushbutton tone controls) SWTPC .01 amps Dual 1229 table Stanton 681EEE cartridge homebrew loudspeakers, 2.5 cu ft Norelco 1256M drivers with Motorola piezoelectric horn tweeters (for that extra sizzle) Marantz cassette deck (5420, I think - the one with the mixer in it) The cassette deck still sees occasional use today. - -- Dan Kerl dlkerl@ro.com ========================================================================= From: kjartan@ejs.is Subject: [JN] Re: 1976? Date: Tue, 11 Jan 2000 12:40:25 -0000 Source: Sound Digest Archive v02.n396 My first system, bought it in 1975 in stead of a 50cc Honda -couldn't afford both. Sansui 7800 (I think) amp. 2 way Epicure speakers JVC (something) turntable Pioneer cassette tape Today I probably wouldn't like this system at all -- but then it was wonderful. Main diet at the time Pink Floyd, Yes, Genesis, Gentle Giant, Emerson, Lake & Palmer, Focus (or was that later - don't remember), Jethro Tull, Led Zeppelin, etc. Kjartan Iceland. ========================================================================= From: David Barnett Subject: Re: [JN] Re: 1976? Date: Tue, 11 Jan 2000 13:37:23 -0600 Source: Sound Digest Archive v02.n396 On Tue, 11 Jan 2000 12:40:25 -0000, kjartan@ejs.is wrote: >Main diet at the time Pink Floyd, Yes, Genesis, Gentle Giant, Emerson, Lake >& Palmer, Focus (or was that later - don't remember), Jethro Tull, Led >Zeppelin, etc. And you admit this in public? Those, and King Crimson, were tops on my musical diet at the time too, to a tee. Fortunately I was "saved" in 1977 by Johnny Rotten, Tom Verlaine, Elvis Costello and other punks who made me instantly discard my prog-rock roots. (I still kinda like Led Zep, though, I'm embarrassed to admit...) - --dnb ========================================================================= From: Thomas Dunker Subject: Re: [JN] 1976? Date: Tue, 11 Jan 2000 15:17:23 +0100 (CET) Source: Sound Digest Archive v02.n396 On Mon, 10 Jan 2000, David Barnett wrote: > On Sun, 9 Jan 2000 19:31:10 EST, Ishmael349@aol.com wrote: > > >What were > >YOU using to listen to music in 1976? > > As long as we're all trotting out the skeletons in our closets, I had > a pair of Dynaco A25XL speakers, a Dynaco SCA-80Q integrated amp (I > learned how to solder by assembling that kit), a Viking 76 tube > reel-to-reel, and the dreaded Philips GA-212 turntable with some sort > of B&O cartridge. For a little audio trivia - the Dynaco A25 speaker was one of the most famous designs by our Norwegian speaker designer celebrity Ragnar Lian who I've refered to in many previous posts. Other than that I have not ever seen nor listened to these speakers, they're anything but common over here in our corner of the world. Also, I was four years old in 1976 and the only "hi-fi" I may have listened to back then was my father's Philips record player, which was like a semi-portable integrated thing with detachable speakers, all in plastic. I remember listening to old Beatles singles, Mozart, Vivaldi, Georges Moustaki and particularly an LP with "Ole Brumm" (Winnie-the-Pooh) stories on this record player. It was all quite magical back then, and my parents had to be called upon to change and flip records, as I was, perhaps thankfully, too small to reach the record player which sat in a bookshelf. To the amazement of my friends and parents I put together a system, first in mono, using an efficient SEAS full range TV speaker fed by my prehistorical "walkman", a "Philips Skymaster" and later I ripped the whooping 3W amp out of some portable Philips record player, which went loud enough to annoy my parents when I hooked it to a speaker equipped with a late 40's Tandberg "type 165" full range 8", ripped out of some old radio. Later still, when I was about 12, I built a stereo system using a Garrard SP25 turntable and two Tandberg Sřlvsuper 9 radios as monoblocks, naturally a true dual mono setup, complete with SE 6BQ5 power amps, again feeding a pair of speakers with some sort of efficient full range drivers. I also built a number of exceedingly ugly and poor sounding speakers in shop class during grade school. But the DIY thrill must have been with me since I was about 10. Tubes were a natural ingredient, as my friend Roger and I rounded up all sorts of dumped TVs and radios and begged the TV repair shops to give us their junk, and dumpster diving was a near daily activity back then, as the shops got annoyed and sometimes dumped loads of stuff that they wouldn't give us when we asked. Roger and I were nerds at age 7, before we knew what nerds were, and accumulated huge amounts of electronic junk, to our parents' unending dismay. Besides audio, we dabbled with radio transmitters and operated an FM transmitter for as long as the tractor battery would last, we had no charger. Later, Roger built a tubed FM transmitter that retransmitted audio from MTV off satellite for miles around (we had no local radio stations back then, so quite a few kids tuned in). This thing naturally ran on high voltage and was tuned by visually observing the glow of the EL84's plate and screen grid. It eventually died after a year's continuous duty, the poor EL84 always on the brink of meltdown, when Roger's cat somehow tripped and damaged the HT power supply. The cat survived, but the power supply died. We had a lot of fun back then. Tom - ------------------------------------------------------------------------ _/\_ Thomas Dunker \ The Horn Speaker Home Page: / \ P.O.Box 2811 \ http://invalid.ed.ntnu.no/~dunker/horns.html | | 7002 Trondheim \ | | NORWAY \--\ "Those with head above water \____/ dunker@omegav.ntnu.no \ see only the tip of the iceberg" |||| phone: (+47)73911068 \ (Gene Dalby) - ------------------------------------------------------------------------ ========================================================================= From: evaguido Subject: Re: [JN] Re: 1976? Date: Tue, 11 Jan 2000 23:06:13 +0100 Source: Sound Digest Archive v02.n397 >Philips 2x30W class A amplifier, Philips class A ? Could you help me giving the type nr ? I am surprised ! regards Guido >Gerhard from Berlin > > ========================================================================= From: Gerhard Dierkes Subject: Re: [JN] Re: 1976? Date: Wed, 12 Jan 2000 08:02:24 +0100 Source: Sound Digest Archive v02.n397 Hello Guido, I cannot remember the number. It had a brushed aluminium front, two fancy round VU-Meters at the left side and a big volume knob on the right side. Underneath were many switches: phono, tuner, tape, aux1, aux2 rumble filter, high blend ... I sold it later for a bigger amp (2x120W) but today I regret this step. regards Gerhard from Berlin >>Philips 2x30W class A amplifier, >Philips class A ? >Could you help me giving the type nr ? I am surprised ! >regards >Guido ========================================================================= From: Tim_Bailey@medibank.com.au Subject: Re: [JN] 1976? Date: Wed, 12 Jan 2000 13:20:40 +1100 Source: Sound Digest Archive v02.n397 **************************************************************** NOTICE - This message is intended only for the use of the addressee named above and may contain privileged and confidential information. If you are not the intended recipient of this message you are hereby notified that you must not disseminate, copy or take any action based upon it. If you received this message in error please notify Medibank Private Ltd immediately. Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Medibank Private Ltd. **************************************************************** No David No, not like Jecklins they were sort of squarish with rounded corners and had an isodynamic driver ie magnets but a film planar diaphragm with a printed circuit coil, I think. I had a pair of Sennheiser HD414's back then an until the late '80's, they went through two sets of foam pads before I blew. them up. tim B ========================================================================= From: evaguido Subject: Re: [JN] Re: 1976? Date: Wed, 12 Jan 2000 19:14:17 +0100 Source: Sound Digest Archive v02.n398 Gerhard, OK, get the desription, but full class A ? regards, - - Guido At 08:02 12/01/00 +0100, Gerhard Dierkes wrote: >Hello Guido, > >I cannot remember the number. It had a brushed aluminium front, >two fancy round VU-Meters at the left side and a big volume knob >on the right side. Underneath were many switches: phono, tuner, tape, >aux1, aux2 rumble filter, high blend ... I sold it later for a bigger >amp (2x120W) but today I regret this step. > >regards > >Gerhard from Berlin > >>>Philips 2x30W class A amplifier, > >>Philips class A ? > >>Could you help me giving the type nr ? I am surprised ! > >>regards > >>Guido > > ========================================================================= From: Paul Butterfield Subject: Re: [JN] Re: 1976? Date: Thu, 13 Jan 2000 23:38:02 -0500 Source: Sound Digest Archive v02.n401 >What were YOU using to listen to music in 1976? Ah well now, that was the very year I was seduced (in October) to the big sand sound of solid state, sold my Pilot tube amp, and purchased... Pioneer SX1050 '120 watt' amplifier Pioneer PL 530 turntable w/ Shure M-44 E Infinity Monitor IIa speakers (Walsh tweets) TEAC A 4300 reel to reel recorder ... and all except the Infinity's are still working today. Paul ========================================================================= From: connlyra@gol.com Subject: [JN] Re: 1976? Date: Fri, 14 Jan 2000 10:56:01 +0900 Source: Sound Digest Archive v02.n401 1976 was a long time ago. But at least my first tube amp had been playing for a few years, and I was reading Musen to Jikken (later renamed to M&J), Rajio Gijutsu, Denpa Kagaku and some of the other Japanese electronic technology / DIY publications. jonathan carr ========================================================================= From: Paul Croft Subject: RE: [JN] 1976? Date: Fri, 14 Jan 2000 16:17:08 -0500 Source: Sound Digest Archive v02.n403 Wow, I can't help it. This is getting tooo good! Dan, I had the SWTPC preamp with a pair of his mono-block 80watt amps. I ran these with a Dual 1219 turntable. I had a great old pair of Dynaco ST-25s. Actually, it has taken me a long time to better that system. Hmm, I remember the preamp would tend to motor-boat when the loudness control was in. Ah, boy meets stereo and DIY... When I was stationed at Lackland RAF base, I blew one of the woofers. I sent a sad note back Dynaco about 10 pounds of music... and please hurry! They were kind enough to replace it for free. Hmm, this must of been '71 or '72. Jeez, I hope this isn't what caused the final demise. Whew, lots of rock'n roll back then, and I still have my Firesign Theater albums, "We're All Bozos on this Bus" being the last. I'm glad to here their still making CDs. Really good stuff! Now I have Doc Bottlehead's Foreplay preamp, a Dynaco ST-70 with the Welbourne Labs mods, Sheldon Stoke's hollowstate Big DAC and the Avatar Audio 281 TL kit for speakers. Whew, the speakers took forever to break in but are really startin' to cook, now! It's neat having an amp almost as old as I am. And better preserved through parts replacements, I must say. I forget who the dingbat was that suggested an ST-70 can't sound good. I think we should all take up a collection and buy him a box of Q-Tips! Cheers, Paul Back to lurk-o-matic... - -----Original Message----- From: Dan Kerl [SMTP:dlkerl@ro.com] Sent: Tuesday, January 11, 2000 10:18 AM To: sound@lists.io.com Subject: Re: [JN] 1976? With co-op money (the most spendable money I ever had): SWTPC preamp (trick pushbutton tone controls) SWTPC .01 amps Dual 1229 table Stanton 681EEE cartridge homebrew loudspeakers, 2.5 cu ft Norelco 1256M drivers with Motorola piezoelectric horn tweeters (for that extra sizzle) Marantz cassette deck (5420, I think - the one with the mixer in it) The cassette deck still sees occasional use today. - -- Dan Kerl dlkerl@ro.com ========================================================================= From: "dehls" Subject: Re: [JN] 1976? Date: Sat, 15 Jan 2000 17:38:21 -0800 Source: Sound Digest Archive v02.n405 1976, a very good year, I think ;-) Altec Barcelona speakers Lux tube electronic xover ESS Eclipse SS amp on the woofers Mac 275 on the horns Marantz 7C pre-amp Marantz 10B tuner Revox A77 RR Ariston RD11s/SME 3009/Denon 103c/Denon transformer I sure had a lot of fun with that system, wish I still had it. Take Care, David ========================================================================= From: "Miroslav Kubala" Subject: [JN] 1976? Date: Sun, 16 Jan 2000 10:13:29 +0100 Source: Sound Digest Archive v02.n405 David wrote: > Altec Barcelona speakers > Lux tube electronic xover > ESS Eclipse SS amp on the woofers > Mac 275 on the horns > Marantz 7C pre-amp > Marantz 10B tuner > Revox A77 RR > Ariston RD11s/SME 3009/Denon 103c/Denon transformer WOW!!!!!!!! My system 1976: selfconstructed Fostex-horn bacloaded with a borowed Lowther PM6 ( I newer gave back...) The cheepest Micro with Shure V15 SS preamp- board ( kit) on a piece of wood kind of pp EL84 amp 800 LPs Suzuki cross-motorcycle I was driving without a licence-plate and Lot of trouble These years music was my only happy feeling Mirko ========================================================================= From: Tim_Bailey@medibank.com.au Subject: Re: [JN] 1976? Date: Mon, 17 Jan 2000 11:49:48 +1100 Source: Sound Digest Archive v02.n405 **************************************************************** NOTICE - This message is intended only for the use of the addressee named above and may contain privileged and confidential information. If you are not the intended recipient of this message you are hereby notified that you must not disseminate, copy or take any action based upon it. If you received this message in error please notify Medibank Private Ltd immediately. Any views expressed in this message are those of the individual sender, except where the sender specifically states them to be the views of Medibank Private Ltd. **************************************************************** gee david (jealously) I hope you haven't had any slide in your economic circumstances since! some of this gear some people would still kill for. what do you listen to now? tim B ========================================================================= From: "dehls" Subject: Re: [JN] 1976? Date: Mon, 24 Jan 2000 21:43:58 -0800 Source: Sound Digest Archive v02.n419 Hi Tim, I was working at a stereo store at the time. Most of that gear was purchased used for less than I can believe. People were giving that old tube stuff away for that new and improved transistor stuff. The Mac and Marantz pieces were the better part of the down payment for my 1st house. Wish I'd kept the gear :-( My current systems consist of: System 1: Lowther PM2A's in Medallion enclosures Quicksilver SE300B monoblocks Quicksilver Linestage preamps (one for each channel) Quicksilver Phono preamp Micro-Seiki RDX1500/ET2/Denon103c/Quicksilver step up Pioneer DVD for cd's and 24/96 discs System 2: Quad ESL57 Caztech SE845 monoblocks Paracas Sierra preamp Ampex tube RR Pioneer Laserdisc for cd's System 3(video): Klipsch corner horns Quicksilver 8417's modified to accept EL34's by Mike Sanders Mac MX110 tuner/preamp Pioneer DVD Panasonic VCR And, most importantly, my _very_ understanding bride of 14 years who continues to put up with me! Take Care, David - ---------- > From: Tim_Bailey@medibank.com.au > To: sound@io.com; dehls > Subject: Re: [JN] 1976? > Date: Sunday, January 16, 2000 4:49 PM > > **************************************************************** > NOTICE - This message is intended only for the use of the > addressee named above and may contain privileged and > confidential information. If you are not the intended recipient > of this message you are hereby notified that you must not > disseminate, copy or take any action based upon it. If you > received this message in error please notify Medibank > Private Ltd immediately. Any views expressed in this > message are those of the individual sender, except where > the sender specifically states them to be the views of > Medibank Private Ltd. > **************************************************************** > > > > gee david (jealously) > > I hope you haven't had any slide in your economic circumstances since! > > some of this gear some people would still kill for. > > what do you listen to now? > > tim B > ========================================================================= From: houndman@onix.com Subject: Re: [JN] 1976? Date: Thu, 27 Jan 2000 15:56:28 -0500 Source: Sound Digest Archive v02.n420 I was working for Music & Sound Ltd in Pa and knew the Japanese were buying a lot of old US gear but just heard they were buying old SE gear. Been out of the loop for a long time but wonder why I didn't hear about it back then. Maybe it was an underground thing. - ----------------- \/ince ++ working on breeding an Afghan that Doesn't mat.... And comes when called... ========================================================================= From: David Barnett Subject: Re: [JN] 1976? Date: Thu, 27 Jan 2000 19:20:18 -0600 Source: Sound Digest Archive v02.n420 On Thu, 27 Jan 2000 15:56:28 -0500 , houndman@onix.com wrote: > I was working for Music & Sound Ltd in Pa and knew the Japanese were >buying a lot of old US gear but just heard they were buying old SE gear. WHAT old SE gear? Apart from the WE91 and the amps in old stereo consoles, radios, car radios and TVs, I don't know of any SE amps from the "golden years" of US hifi. - --dnb ========================================================================= From: Rick Francis Subject: Re: [JN] 1976? Date: Thu, 27 Jan 2000 21:59:39 -0500 Source: Sound Digest Archive v02.n420 At 07:20 PM 1/27/00 -0600, David Barnett wrote: >On Thu, 27 Jan 2000 15:56:28 -0500 , houndman@onix.com wrote: > >> I was working for Music & Sound Ltd in Pa and knew the Japanese were >>buying a lot of old US gear but just heard they were buying old SE gear. > >WHAT old SE gear? Apart from the WE91 and the amps in old stereo >consoles, radios, car radios and TVs, I don't know of any SE amps from >the "golden years" of US hifi. > That's MOSTLY true, but there were a handful of "high fidelity" (as opposed to console) single-ended (pentode) amps sold in the 50s and 60s. For a while I owned an Eico SE 6BQ5 FM stereo receiver, and Dan Marshall mentioned a Lafayette SE receiver recently, I think. I've seen Lafayette, Pioneer, Monarch, and a few other units using single-ended outputs... I recently came across a high-quality Roberts reel-to-reel with a pair of SE 6BQ5 amps inside. None of these are WE91's, but seem worthy of a footnote, IMO. Rick ========================================================================= From: Peter Sikking Subject: Re: [JN] Re: 1976? Now Philips amps and pipe speaks... Date: Wed, 12 Jan 2000 15:55:50 +0100 Source: Sound Digest Archive v02.n398 Guido wrote: > >Philips 2x30W class A amplifier, > > Philips class A ? > > Could you help me giving the type nr ? I am surprised ! ag9014, ag9015, ag9018 are class A. I think you have still one of these at home. Speaking of, I finally hooked up the 800 Ohm drivers I got from you. Even though the cones are made of cardbox, or some kind of woven material, the sound is fast. I need to go to the DIY store to get some 20x155 cm pipes (like JC in SP6). Last saturday I got bitten by the first law of Germany ("stores are closed when consumers are able to go shopping"), so now they are playing in two rolled-up futon matrases. Not quite the lenght (70cm) bot there is already some lo' end. Does anybody have a copy of the speaker builder article (Weems, '87) mentioned by JC in SP6? --Peter : music lover : ultra-fi builder : ui & oo designer & developer : on drums... : from:amsterdam@berlin : +49 173 800 60 37 : facsimile +49 30 390 94 300 ========================================================================= From: evaguido Subject: Re: [JN] Re: 1976? Now Philips amps and pipe speaks... Date: Wed, 12 Jan 2000 19:14:16 +0100 Source: Sound Digest Archive v02.n398 At 15:55 12/01/00 +0100, Peter Sikking wrote: >Guido wrote: > >> >Philips 2x30W class A amplifier, >> >> Philips class A ? >> >> Could you help me giving the type nr ? I am surprised ! > >ag9014, ag9015, ag9018 are class A. Yes but these are not from 76'........ >I think you have still one of these at home. Yes ! >Speaking of, I finally hooked up the 800 Ohm drivers I got from you. >Even though the cones are made of cardbox, or some kind of woven material, >the sound is fast. Oh great. You bought some AD9710 ! Do these have the well known peak at 2 kHz ? >I need to go to the DIY store to get some 20x155 cm pipes (like JC in SP6). >Last saturday I got bitten by the first law of Germany ("stores are closed when >consumers are able to go shopping"), so now they are playing in two rolled-up >futon matrases. Not quite the lenght (70cm) bot there is already some lo' end. I used to use carpet, formed to a pipe, with AD5061 5"" units, years ago. quarter labda, great bass! regards Guido >Does anybody have a copy of the speaker builder article (Weems, '87) mentioned >by JC in SP6? > > --Peter > >: music lover : ultra-fi builder : ui & oo designer & developer : on drums... >: from:amsterdam@berlin : +49 173 800 60 37 : facsimile +49 30 390 94 300 > > ========================================================================= From: Peter Sikking Subject: Re: [JN] Re: 1976? Now Philips amps and pipe speaks... Date: Thu, 13 Jan 2000 13:44:45 +0100 Source: Sound Digest Archive v02.n400 Guido wrote: > >ag9014, ag9015, ag9018 are class A. > Yes but these are not from 76'........ OK OK, you're right. > >Speaking of, I finally hooked up the 800 Ohm drivers I got from you. > >Even though the cones are made of cardbox, or some kind of woven material, > >the sound is fast. > Oh great. You bought some AD9710 ! That's the number. > Do these have the well known peak at 2 kHz ? Don't know, also don't have anything to measure this apart from my ears and a CD with frequency sweep, will try that when they are on a pipe. THey sure beam in the treble. > >I need to go to the DIY store to get some 20x155 cm pipes (like JC in SP6). > I used to use carpet, formed to a pipe, with AD5061 5"" units, years ago. > quarter labda, great bass! This combined with my futon rig makes me think about a "the lining _is_ the pipe" type of setup. --Peter : music lover : ultra-fi builder : ui & oo designer & developer : on drums... : from:amsterdam@berlin : +49 173 800 60 37 : facsimile +49 30 390 94 300 ========================================================================= From: Gerhard Dierkes Subject: [JN] Re: 1976? Philips amp Date: Thu, 13 Jan 2000 08:17:18 +0100 Source: Sound Digest Archive v02.n400 Guido, >OK, get the desription, but full class A ? As I remember, yes. The cooling radiator on the back of the amp got so hot that you could not touch them longer than fifteen seconds ! At that time Philips made advertisements that this amp was better than the German standard *HiFi Norm 45500* and on front of the thing was the emblem for this standard. Today this standard is ridiculous bad. ...Gerhard ========================================================================= From: evaguido Subject: [JN] Re: 1976? Philips amp Date: Fri, 14 Jan 2000 23:50:41 +0100 Source: Sound Digest Archive v02.n404 At 08:17 13/01/00 +0100, Gerhard Dierkes wrote: >Guido, > >>OK, get the desription, but full class A ? > >As I remember, yes. The cooling radiator on the back of the >amp got so hot that you could not touch them longer than >fifteen seconds ! :-) At that time Philips made advertisements >that this amp was better than the German standard *HiFi Norm >45500* :-)) and on front of the thing was the emblem for this >standard. Today this standard is ridiculous bad. Well, with respect to sonic quality: yes Have fun Guido >...Gerhard > > ========================================================================= From: TubeGarden@aol.com Subject: [JN] $1.98 Beauty Contest - HOLCO Date: Fri, 14 Apr 2000 00:34:23 EDT Source: Sound Digest Archive v02.n520 Greets Jeets Neets! Got some HolCo 1/4W 0.1% resistors from aes. of 4 each 15R pieces, 3 measured 15.0, one measured 12.2 first time in my life I am returning a resistor, $0.99 each, I get touchy, y'know? meanwhile, one of each are my Rk on the SV83, dissipating < 110 mW. They really sound better, more detail, 'space', scale, than the 2W Xicon they replaced. OK, now I hear resistors, time to get my meds increased? Happy Ears! Al B^} ========================================================================= From: Owen Young Subject: Re: [JN] $1.98 Beauty Contest - HOLCO Date: Fri, 14 Apr 2000 22:44:36 +1200 Source: Sound Digest Archive v02.n520 Hi Al Michael Percy has Holco H4 0.5W 1% for $0.45 ea if it's of any use to you. H2 1.0W for $0.65 ea. Rgds Owen TubeGarden@aol.com wrote: > Got some HolCo 1/4W 0.1% resistors from aes. > of 4 each 15R pieces, 3 measured 15.0, one measured 12.2 > first time in my life I am returning a resistor, $0.99 each, I get touchy, > y'know? ========================================================================= From: Robert C Chambers Subject: 1995 Andy Grove 6922/Was Re: [Re: [JN] was 1 tube phono now 1 2b amp] Date: Tue, 1 Feb 2000 09:08:35 -0500 (EST) Source: Sound Digest Archive v02.n429 Hello- Where can I find this one? Robert On 1 Feb 2000, johari yip wrote: > "Hugh R. Dean" wrote: > > > Incidentally, a friend is furiously building and testing tube phono stages. > > His verdict so far? The 1995 Andy Grove 6922 is probably the best of them. > > > > Hugh, > > I couldn't agree with you more...have been listening to this one close to two > years now and so far, have not hear a mm phonostage come close....marvelous > sounding. > > johari > > > ____________________________________________________________________ > Get free email and a permanent address at http://www.netaddress.com/?N=1 > ========================================================================= From: connlyra@gol.com Subject: [JN] 1999 Stereo Sound COTY award Date: Thu, 16 Dec 1999 23:21:24 +0900 Source: Sound Digest Archive v02.n365 Hi all I just wanted to mention that we have received the 1999 Component of the Year award from Stereo Sound (Japan's most prestigious audio magazine) for the Connoisseur 3.0 preamp, and this is for a solid-state design (with lots of feedback, yet) that retails for a cool Ą4,500,000. While we have collected a number of awards for various cartridge designs over the years, the truth is that I only design the cartridges - I don't build them. But I *have* been responsible for designing, "voicing" as well as crafting the Connoisseur, so this award feels very good indeed - likely because of the intense degree of personal involvement. On top of that, while we originally planned to make only 14 pieces, we are all sold out and have orders for more. That means another big outlay for parts and a lot more work ahead, but somehow I don't mind :-) All of this feels like a wonderful Christmas gift. I will have to see if we can get a repeat award next year! (working on a more affordable design right now) Sorry for wasting bandwidth, and apologies for bragging, but right now I feel very, very happy. I wish you all as much happiness for the Christmas season as I am feeling right now. jonathan carr ========================================================================= From: "Multi-Volti Devices" Subject: [JN] 1) Any physicists on the List? 2) Any Taiwan residents on the list/ Date: Sat, 10 Apr 1999 00:26:24 -0400 Source: Sound Digest Archive v02.n119 Hello: Two separate requests...need not be a Chinese physicist! 1) I would like to correspond with someone to work thru some arithmetic derivations of L and C with respect to physical geometries, as applied to transformer windings. I have plenty of 'textbook' formulae that address some 'standard' winding geometries, but I want to explore combined horizontal interleaving with vertical sectionalizing in combinations not in textbooks. I'm sure I can do the math...it's just that I will also probably overlook issues like fringing and sometimes when 'reverse deriving', one can jump to the wrong conclusions. 2) Taiwan residents...I own some test equipment manufactured by King Instruments that is in need of repair. A contact at a company in TaiwanI worked with (a vendor) contacted King for me, but they had no documentation (1986...too old). I am hoping I might be able to hook up with someone to run an ad in an electronics hobbyist magazine in Taiwan, if one exists, searching for a schematic for the one piece of equipment. Of course, I can provide model numbers. Thanks Murray ========================================================================= From: "Jan Hass" Subject: [JN] 1" drivers. Date: Fri, 20 Apr 2001 21:18:08 +0200 Source: Sound Digest Archive v02.n871 This is a multi-part message in MIME format. - ------=_NextPart_000_0016_01C0C9DF.659F42C0 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0017_01C0C9DF.659F42C0" - ------=_NextPart_001_0017_01C0C9DF.659F42C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit FestDear Larry, Steve, BobC, Manfred, PeterC, Mathias, Torbjřrn et al......... Hope i didn´t forget anyone Thanks for your replys regarding questions about a suitable 1" high frequency driver. It is very difficult when you are not able to hear these things. There have been suggested JBL`s, Altecs, B&C, Radians. My dealer says that the BMS drivers are top of the pops - that they go deeper and higher than almost everything else. Anyone here familiar with the BMS drivers. Can´t find much info on them on the web - no links - no website -the company is supposed to be German says Manfred....... There is a little info on the Adam Hall website ( www.adamhall.com but no curves. Greatings Jan Hass - - We help open the heart of your music - www.hifi-analyse.dk mailto:info@hifi-analyse.dk - ------=_NextPart_001_0017_01C0C9DF.659F42C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Fest
Dear Larry, = Steve, BobC,=20 Manfred, PeterC, Mathias, Torbj=F8rn et al.........
 
Hope i = didn=B4t forget=20 anyone
 
Thanks for = your replys=20 regarding questions about a suitable 1" high frequency driver. It is = very=20 difficult when you are not able to hear these things. There have been = suggested=20 JBL`s, Altecs, B&C, Radians. My dealer says that the BMS drivers are = top of=20 the pops - that they go deeper and higher than almost=20 everything else. 
Anyone here = familiar=20 with the BMS drivers. Can=B4t find much info on them on the web - = no links -=20 no website -the company is supposed to be German says=20 Manfred.......
There is a = little info=20 on the Adam Hall website  ( www.adamhall.com but no=20 curves.
 
Greatings
 
Jan=20 Hass

- We help open the heart of your music -
www.hifi-analyse.dk
mailto:info@hifi-analyse.dk

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Date: Sat, 21 Apr 2001 02:12:30 +0200 Source: Sound Digest Archive v02.n871 This is a multi-part message in MIME format. - ------=_NextPart_000_0008_01C0CA08.84E62BC0 Content-Type: multipart/alternative; boundary="----=_NextPart_001_0009_01C0CA08.84E62BC0" - ------=_NextPart_001_0009_01C0CA08.84E62BC0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit FestHi My friend Kim sent me this link to BMS. Have a look. Cool 2-way driver. http://www.bmselektronik.de/english/products/2coax.htm Greatings Jan Hass - ------=_NextPart_001_0009_01C0CA08.84E62BC0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Fest
Hi =
 
My friend = Kim sent me=20 this link to BMS. Have a look.
Cool 2-way=20 driver.
 
http://www.bmselektronik.de/english/products/2coax.htm
 
Greatings
 
Jan=20 Hass
 

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Gn/G2Tl/vlcf7iT/AGf62x6hVU9R8/4ZWUt4UP8A/9k= - ------=_NextPart_000_0008_01C0CA08.84E62BC0-- ========================================================================= From: MHuber@t-online.de (Manfred Huber) Subject: Re: [JN] 1" drivers. Date: Sat, 21 Apr 2001 14:00:31 +0200 Source: Sound Digest Archive v02.n872 - --_=_=_=IMA.BOUNDARY.HTML_4924592=_=_=_ Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jan, Anyone here familiar with the BMS drivers. Can=A6t find much info on the= m on the web - - no links - no website -the company is supposed to be German says Manfr= ed....... This is the BMS Homepage: http://www.bmselektronik.de/ The 2" coax compression driver is not even very expensive: Euro 380.- / ea You can buy it here: http://www.netzmarkt.de/thomann/gruppe-PASP-1.html Achenbach is also offering the BMS 1" drivers at good prices: http://www.lsv-achenbach.de/shop2/index.htm Regards Manfred - ------------------ Manfred Huber MHuber@t-online.de - ------------------ - --_=_=_=IMA.BOUNDARY.HTML_4924592=_=_=_ Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Jan,

Anyone here familiar with the BMS drivers. Can=A6t = find much info on them on the web
- - no links - no website -the company is supposed to be German says Manfr= ed.......


This is the BMS Homepage: http://www.bmselektronik.de/

The 2" coax compression driver is not
even very expensive: Euro 380.- / ea
You can buy it here: http://www.netzmarkt.de/thomann/gruppe-PASP-1.html<= BR>
Achenbach is also offering the BMS 1" drivers at good prices:
http://www.lsv-achenbach.de/shop2/index.htm

Regards
Manfred

- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------ - --_=_=_=IMA.BOUNDARY.HTML_4924592=_=_=_-- ========================================================================= From: "Jan Hass" Subject: [JN] 1" high frequency drivers. Date: Wed, 18 Apr 2001 11:22:41 +0200 Source: Sound Digest Archive v02.n868 This is a multi-part message in MIME format. - ------=_NextPart_000_0008_01C0C7F9.E1C76860 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit Hi Joe´s Anyone familiar with - or any recommandation on 1" / 16 ohms compression driver that are able to cover the frequency from 1.5 khz to 20 khz. How about old JBL`s 2412B or 2425H units are they up to this ? I can´t afford the TAD, AEL, Goto and Onkens. Greatings Jan Hass - ------=_NextPart_000_0008_01C0C7F9.E1C76860 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi=20 Joe=B4s
 
Anyone familiar=20 with - or any recommandation on 1" / 16 ohms compression driver = that are=20 able to cover the frequency from 1.5 khz to 20 khz. How about old JBL`s = 2412B or=20 2425H units are they up to this ?
 
I can=B4t=20 afford the TAD, AEL, Goto and Onkens.
 
Greatings Jan=20 Hass

 

 
- ------=_NextPart_000_0008_01C0C7F9.E1C76860-- ========================================================================= From: "Jan Hass" Subject: SV: [JN] 1" high frequency drivers. Date: Wed, 18 Apr 2001 20:44:36 +0200 Source: Sound Digest Archive v02.n868 Hi Bob Thanks for your reply ! Do you have any personal experience with the JBL 2410 / 2420 drivers ? What dos IIRC mean - and I don´t understand the 175-275 number. What is it ? Greatings Jan Hass >Hi Joe´s > >Anyone familiar with - or any recommandation on 1" / 16 ohms compression driver >that are able to cover the frequency from 1.5 khz to 20 khz. How about old JBL`s >2412B or 2425H units are they up to this ? >I can´t afford the TAD, AEL, Goto and Onkens. >Greatings Jan Hass I think the Drivers you might want to look for IIRC are JBL 2410-2420 or a 175-275... regards BC ========================================================================= From: "BobC" Subject: Re: [JN] 1" high frequency drivers. Date: Thu, 19 Apr 2001 10:44:21 -0400 Source: Sound Digest Archive v02.n868 >Hi Joe´s > >Anyone familiar with - or any recommandation on 1" / 16 ohms compression driver >that are able to cover the frequency from 1.5 khz to 20 khz. How about old JBL`s >2412B or 2425H units are they up to this ? >I can´t afford the TAD, AEL, Goto and Onkens. >Greatings Jan Hass I think the Drivers you might want to look for IIRC are JBL 2410-2420 or a 175-275... regards BC ========================================================================= From: Steve Van Osdell Subject: Re: SV: [JN] 1" high frequency drivers. Date: Wed, 18 Apr 2001 23:20:41 -0400 Source: Sound Digest Archive v02.n869 Jan, The ONLY JBL driver I would recommend that would even come close is the 2420, or LE375 (same thing), and I can promise you that it will only get you up to maybe 15K with any authority (lot depends on your horn choice). The other drivers I would recommend you check out are the Altec 902 and 802 series (with all aluminum diaphragms), or for new stuff and if you might consider 2" throat, there is the DE750 from B&C Speakers (www.bcspeakers.com). It is going to be very difficult, I can tell you for sure, to get up to 20K and all the way down to 500-800Hz with the same driver. I have a pair of TAD 2001's and TAD4001's, and I have opted to use Fane ST5022 bullet tweeters for the last octave (10K - 20K) even with these fine drivers (but I am using them in big horns and going for low response more than for high). Steve Jan Hass wrote: > Hi Bob > > Thanks for your reply ! > > Do you have any personal experience with the JBL 2410 / 2420 drivers ? > What dos IIRC mean - and I don´t understand the 175-275 number. What is it ? > > Greatings Jan Hass > > >Hi Joe´s > > > >Anyone familiar with - or any recommandation on 1" / 16 ohms compression > driver >that are able to cover the frequency from 1.5 khz to 20 khz. How > about old JBL`s >2412B or 2425H units are they up to this ? > > >I can´t afford the TAD, AEL, Goto and Onkens. > > >Greatings Jan Hass > > I think the Drivers you might want to look for IIRC are JBL 2410-2420 or a > 175-275... > > regards > BC ========================================================================= From: Larry Van Wormer Subject: Re: SV: [JN] 1" high frequency drivers. Date: Thu, 19 Apr 2001 06:06:54 -0400 Source: Sound Digest Archive v02.n869 A very good modern driver, as mentioned a while ago by Tom Danley, is the Radian 475PB, which is available in a 16 ohm version: http://www.radianaudio.com/products/compression/compression_drivers_model_475pb.htm Works fine down to 800 Hz, and up past 20 kHz, with the right horn, check Radian's products in that area as well. Larry Van Wormer > Jan Hass wrote: > > >Hi Joe´s > > > > > >Anyone familiar with - or any recommandation on 1" / 16 ohms compression > > driver >that are able to cover the frequency from 1.5 khz to 20 khz. How > > about old JBL`s >2412B or 2425H units are they up to this ? > > > > >I can´t afford the TAD, AEL, Goto and Onkens. > > > > >Greatings Jan Hass ========================================================================= From: "Eric Weitzman" Subject: [JN] 1 kHz square wave - RIAA filtered Date: Sun, 12 Nov 2000 11:27:35 -0800 Source: Sound Digest Archive v02.n731 Hi. I've created a wave file of a 1kHz square wave that's been filtered by the RIAA recording curve. I uploaded it to the xdrive into folder "1 kHz square wave - RIAA filtered". A copy of the text file "1 kHz square wave - RIAA filtered.txt" is attached. I zipped the wave file and a set of graph images so people with low-bandwidth connections can get them easily. If anyone is unable to produce their own longer duration wave files by appending this 1 second clip multiple times, I can create larger files. I'm also willing to redo this with other frequencies. - - Eric These files contain a 1 second, 1kHz, 44.1kHz wave file that has been filtered using a close approximation to the the RIAA Recording curve. My source for the RIAA specification was "Handbook of Recording Engineering" by John Eargle, page 326. All work was done using Cool Edit 2000 version 1.1 under Windoze 2000. I generated a 1 second long 1kHz square wave at 44.1kHz. I set the level to -16db. I chose this level based on trial and error, so that the waveform would not clip after being filtered. I created a FFT filter with the following parameters -20db at 21.53Hz (10Hz) -20db at 50.87 (50Hz) 0db at 503.84 (500Hz) 0db at 1990.97 (2kHz) +20db at 22050hz (20kHz) The transition frequencies are not exact because the program only permits transition frequencies that correspond to integer values scaled from 0 to 4096. The actual spline function used for the smoothing used is not specified in the software package. I tried to use the program's parametric filter, but I couldn't figure out how to convert the filter time constants to "center frequency width Q" values. Eric Weitzman November 12, 2000 ========================================================================= From: "Le Cleac'h Jean-Michel" Subject: Re: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 09:49:10 +0100 Source: Sound Digest Archive v02.n733 - -----Message d'origine----- De : Eric Weitzman Ŕ : sound@lists.io.com Date : dimanche 12 novembre 2000 20:42 Objet : [JN] 1 kHz square wave - RIAA filtered >Hi. > >I've created a wave file of a 1kHz square wave that's been filtered >by the RIAA recording curve. I uploaded it to the xdrive into folder >"1 kHz square wave - RIAA filtered". A copy of the text file "1 kHz square >wave - RIAA filtered.txt" is attached. I zipped the wave file and a set >of graph images so people with low-bandwidth connections can get them >easily. Hello, Could you rename the files you uploaded on xdrive avoiding the sign - It can be difficult for some computer to download the files. Also as you yet give a long name to the folder it is not necessary to keep so long names for the files. I'll upload soon a picture of a 10 microseconde square wave RIAA that I obtain using the Inverse RIAA equalizer designed by Stanley Lipshitz in his paper "On RIAA equalization networks", JAES Vol 27 N°6, June79, pp458-481 Thank you and best regards, Jean-Michel Le Cleac'h, Paris, France ========================================================================= From: "Ion Bebe Bucur" Subject: Re: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 12:43:35 +0200 Source: Sound Digest Archive v02.n733 Hi Jean-Michel, Do you have a copy of Stanley Lipshitz article, please? I'm interested to read it. I'm working on Anzai SRPP modified RIAA and line preamp. It's, in my opinion, the best preamplifier I ever heard (and I did try for a while a lot of well known and expensive preamps) . I found a better regulated power supply for it and I'm very excited because it sounds even better. This preamp is definitely very sensitive to PSU. More, I would check RIAA response accuracy. Warm regards, Ion Bebe Bucur - ----- Original Message ----- From: "Le Cleac'h Jean-Michel" To: Sent: Wednesday, November 15, 2000 10:49 AM Subject: Re: [JN] 1 kHz square wave - RIAA filtered > > -----Message d'origine----- > De : Eric Weitzman > Ŕ : sound@lists.io.com > Date : dimanche 12 novembre 2000 20:42 > Objet : [JN] 1 kHz square wave - RIAA filtered > > > >Hi. > > > >I've created a wave file of a 1kHz square wave that's been filtered > >by the RIAA recording curve. I uploaded it to the xdrive into folder > >"1 kHz square wave - RIAA filtered". A copy of the text file "1 kHz square > >wave - RIAA filtered.txt" is attached. I zipped the wave file and a set > >of graph images so people with low-bandwidth connections can get them > >easily. > > > Hello, > > Could you rename the files you uploaded on xdrive avoiding the sign - > It can be difficult for some computer to download the files. > Also as you yet give a long name to the folder it is not necessary to keep > so long names for the files. > > I'll upload soon a picture of a 10 microseconde square wave RIAA that I > obtain using the Inverse RIAA equalizer designed by Stanley Lipshitz in his > paper "On RIAA equalization networks", JAES Vol 27 N°6, June79, pp458-481 > > Thank you and best regards, > > Jean-Michel Le Cleac'h, Paris, France > > > ========================================================================= From: "Gary Bronner" Subject: Re: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 06:23:43 -0500 Source: Sound Digest Archive v02.n734 Ion, Last month I posted an article by Lipshitz from Audio Amateur magazine describing contruction of an inverse RIAA network. It can still be found at Regards, - ---Gary - ----- Original Message ----- From: "Ion Bebe Bucur" To: "Le Cleac'h Jean-Michel" ; Sent: Wednesday, November 15, 2000 5:43 AM Subject: Re: [JN] 1 kHz square wave - RIAA filtered Hi Jean-Michel, Do you have a copy of Stanley Lipshitz article, please? I'm interested to read it. I'm working on Anzai SRPP modified RIAA and line preamp. It's, in my opinion, the best preamplifier I ever heard (and I did try for a while a lot of well known and expensive preamps) . I found a better regulated power supply for it and I'm very excited because it sounds even better. This preamp is definitely very sensitive to PSU. More, I would check RIAA response accuracy. Warm regards, Ion Bebe Bucur ========================================================================= From: StepHydro@aol.com Subject: Re: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 06:24:25 EST Source: Sound Digest Archive v02.n734 In a message dated 11/15/2000 6: I'm working on Anzai SRPP modified RIAA and line preamp. Ion Bebe, Is there a schema of this preamp on the web? Published anywhere? Cheers/Carron ========================================================================= From: "Paul Croft" Subject: RE: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 10:00:28 -0500 Source: Sound Digest Archive v02.n734 Oh no, Ion. I didn't find them attached! Could have a dirty digital devil have stripped them? I'd love to have a copy! Thanks, Paul > -----Original Message----- > From: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]On > Behalf Of Ion Bebe Bucur > Sent: Wednesday, November 15, 2000 8:39 AM > To: StepHydro@aol.com; sound@lists.io.com > Subject: Re: [JN] 1 kHz square wave - RIAA filtered > > > Hi everybody, > Find, please, attached schematics of phono and line stage. > Ion Bebe Bucur > > ----- Original Message ----- > From: > To: ; > Sent: Wednesday, November 15, 2000 1:24 PM > Subject: Re: [JN] 1 kHz square wave - RIAA filtered > > > > In a message dated 11/15/2000 6: > Eastern Standard , bebe@cstdev.cst.ro writes:> I'm working on > Anzai SRPP > > modified RIAA and line preamp. > > > > > > Ion Bebe, > > > > Is there a schema of this preamp on the web? Published anywhere? > > > > Cheers/Carron > ========================================================================= From: Christian Rintelen Subject: Re: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 13:26:38 +0100 Source: Sound Digest Archive v02.n734 Ion Bebe Bucur wrote: > Do you have a copy of Stanley Lipshitz article, please? I'm interested to > read it. http://www.hagtech.com/pdf/riaa.pdf ========================================================================= From: "Ion Bebe Bucur" Subject: Re: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 15:39:27 +0200 Source: Sound Digest Archive v02.n734 Hi everybody, Find, please, attached schematics of phono and line stage. Ion Bebe Bucur - ----- Original Message ----- From: To: ; Sent: Wednesday, November 15, 2000 1:24 PM Subject: Re: [JN] 1 kHz square wave - RIAA filtered > In a message dated 11/15/2000 6: Eastern Standard , bebe@cstdev.cst.ro writes:> I'm working on Anzai SRPP > modified RIAA and line preamp. > > > Ion Bebe, > > Is there a schema of this preamp on the web? Published anywhere? > > Cheers/Carron ========================================================================= From: "Le Cleac'h Jean-Michel" Subject: Re: [JN] 1 kHz square wave - RIAA filtered Date: Wed, 15 Nov 2000 16:48:37 +0100 Source: Sound Digest Archive v02.n734 - -----Message d'origine----- De : Ion Bebe Bucur Ŕ : Le Cleac'h Jean-Michel ; sound@lists.io.com Date : mercredi 15 novembre 2000 11:47 Objet : Re: [JN] 1 kHz square wave - RIAA filtered >Hi Jean-Michel, >Do you have a copy of Stanley Lipshitz article, please? I'm interested to >read it. >I'm working on Anzai SRPP modified RIAA and line preamp. It's, in my >opinion, the best preamplifier I ever heard (and I did try for a while a lot >of well known and expensive preamps) . I found a better regulated power >supply for it and I'm very excited because it sounds even better. This >preamp is definitely very sensitive to PSU. More, I would check RIAA >response accuracy. Hello, Christian Rintelen gave an URL for Stanley Lipshitz 's paper. Here follows an ASCII schematics for the RIAA equalizer described in "On RIAA equalization networks", JAES Vol 27 N°6, June79, pp458-481 preamp output or CD player or LF generator o | o----o----o R1 = 1,59 MOhm | | R1 C1 | | o----o----o C1 = 2nF | o | o----o----o R2 = 133,9 kOhm | | R2 C2 | | o----o----o C2 = 560pF | o-----O to MM phono input | R3 R3 = 1065 Ohm | o-----O to MC phono input | R4 R4 = 34,8 Ohm | o ground I obtained the R1 to R4 values using normal resistors from the V24 series (sold by Selectronics here in France) in series or in parallel: R1 = 898 kOhm + 353,6 kOhm + 353,8 kOhm R2 = 50kOhm + 10,9kOhm + 74,2 kOhm R3 = 1086 Ohm R4 = 2 resistors of 44 Ohm in parallel Please remark: that equalizer is normally designed to be used with a 300 ohms source impedance. Using that equalizer with a generator having a 600 ohms output impedance or higher may results in a reduced output level under 100 Hertz. There is another inverse RIAA equalizer in S. Lipshitz et W. Jung: "A high accuracy Inverse RIAA network", The Audio Amateur Vol 1, 1980, p22-24. That one is more useful for higher source impedance I think... Best regards, Jean-Michel Le Cleac'h, Paris, France Best regards, Jean-Michel Le Cleac'h ========================================================================= From: "Sellek, Grant (TSA)" Subject: [JN] $1k power cord.. Date: Wed, 24 Feb 1999 16:05:50 +1030 Source: Sound Digest Archive v02.n058 ~ -----Original Message----- ~ From: Derrick Beckner [mailto:dgb@psulias.psu.edu] ~ >steven ~ > 403forbidden.net ~ > ~ >ps: i heard that $1k power cord.. ;-) its okay... ~ ~ ~ Ack! For $1000 it better be FREAKING AWSOME! :) Or at least comparable to the difference between $5000 speakers and $6000 speakers. Would those speakers have to be a freaking awesome difference before you would take the step? Or is the difference sometimes subtle, sometimes swings and roundabouts? I reckon it would be interesting, if you wanted to buy a hi-fi system purely on sound quality from the one supplier (that's a big "if"), to do it all blind. The seller says "let me demo a $7000 system": then he says "for another $1000 it could sound like this", and gives a blind demo, then says "for the same extra $1000 but different components, it could sound like this". The buyer says "yeah, the original system was good, the first $8000 option actually sounded worse to me, but the second one was somehow better, not much mind you, but I liked it enough to take it." "Now, tell me, what did you change on those two options?" "Ah", says the seller, "the first time I changed to more expensive speakers. The second time I put the original speakers back and added a $1k power cord..." "WHAT??? What a rip-off!! You tried to make a fool out of me! The difference wasn't THAT freaking awesome! You just lost my business, buster. I'm going to buy from the shop down the street..." Wake up, wake up! It was only a nightmare..... Grant Grant Sellek Adelaide, Australia grant.sellek@roads.sa.gov.au ========================================================================= From: Kalman Rubinson Subject: Re: [JN] $1k power cord.. -Reply Date: Wed, 24 Feb 1999 13:59:46 -0500 (EST) Source: Sound Digest Archive v02.n059 On Wed, 24 Feb 1999 trs@carlsmith.com wrote: > Someone in the mainstream press (Audio, maybe?) wrote > about how discouraging it must be for the amp designer > that's labored for years to come up with a sub-$1K design > that offers a significant slice of the Krell etc. sound, then > sees someone selling a pair of unbalanced interconnects for > the same price. All I can say is that I paid about the same > for my AN Kit One, and I bet I can tell the difference between > my amp and that $1K cord blindfolded in a dark room (test > conditions: my amp uses its stock rubber toaster cord but is > not connected to anything; to avoid equipment colorations, > $1K power cord is connected directly to speakers [hot to left > channel speaker, neutral to right, ground to both]; speakers > used are Cerwin Vegas my college room mate left in lieu of > rent.) I'll publish the results here first . . . If the other end of the power cord is plugged into an AC socket, it should be easy. Kal ========================================================================= From: trs@carlsmith.com Subject: [JN] $1k power cord.. -Reply Date: Wed, 24 Feb 1999 7:39:21 -1000 Source: Sound Digest Archive v02.n059 Someone in the mainstream press (Audio, maybe?) wrote about how discouraging it must be for the amp designer that's labored for years to come up with a sub-$1K design that offers a significant slice of the Krell etc. sound, then sees someone selling a pair of unbalanced interconnects for the same price. All I can say is that I paid about the same for my AN Kit One, and I bet I can tell the difference between my amp and that $1K cord blindfolded in a dark room (test conditions: my amp uses its stock rubber toaster cord but is not connected to anything; to avoid equipment colorations, $1K power cord is connected directly to speakers [hot to left channel speaker, neutral to right, ground to both]; speakers used are Cerwin Vegas my college room mate left in lieu of rent.) I'll publish the results here first . . . Regards, Tom Sylvester trs@carlsmith.com ========================================================================= From: trs@carlsmith.com Subject: [JN] $1k power cord.. -Reply -Reply Date: Wed, 24 Feb 1999 9:17:41 -1000 Source: Sound Digest Archive v02.n060 Astute 'listers have already pointed out two flaws in my test regime. First, I should have specified that the $1K power cord is plugged directly into an AC outlet. Second, the AN amp should be connected to speakers, but should be driven with a 60 Hz signal to mimic the power line frequency. Well, back to my pitch-black lab. . . Tom Sylvester trs@carlsmith.com ========================================================================= From: "Chris Vryonides" Subject: RE: [JN] 1Mhz Tweeters - correction, it was Max Townshend Date: Thu, 20 Sep 2001 11:25:21 +0000 Source: Sound Digest Archive v02.n980 Sorry, yes, wasn't Morecroft at all. >>>snip Was this Morecroft or Max Townsend cause from a post on another forum..... _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp ========================================================================= From: "Chris Vryonides" Subject: Re: [JN] 1Mhz Tweeters,DC/AC, impedance, bandwidth etc etc Date: Thu, 20 Sep 2001 09:57:23 +0000 Source: Sound Digest Archive v02.n979 Hi all, No, Slagle is right. There is no such thing as dc, if you believe that the universe has finite age... (nice to have you back Dave - glad you're well) The impedance stuff is just nomenclature. Impedance to my mind was just a catch all term for all kinds of resistive/capacitive/inductive "quantities". Maybe we should rename it "hindrance" to keep everyone happy. As for the audibllity of HF, I recall reading something in Stereophile (well dammit, you can't get SP any more, can you) about the ear having a *separate* mechanism which could respond to transients/pulses. Anyway, let's not forget the issue of rise time. Many people forget that frequency response aka fourier transform is only appropriate for repetitive/periodic signals. As I hate most dance music, I'd like for my tweeters to go skyward. Incidentally, HiFi Choice (I really have to trawl through *everything* to find anything interesting these days) had an interview with Morecroft of DNM who claimed to have developed a ribbon that was flat to 200kHz and had detectable output at 1Mhz. Although how he measured all this was unmentioned (strangely). Mesh plate magnetrons, anyone? Cheers all, CV _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com/intl.asp ========================================================================= From: Stephen Robinson Subject: RE: [JN] 1Mhz Tweeters,DC/AC, impedance, bandwidth etc etc Date: Thu, 20 Sep 2001 11:58:39 +0100 Source: Sound Digest Archive v02.n980 > > > Hi all, > > No, Slagle is right. There is no such thing as dc, if you > believe that the > universe has finite age... Of course DC exists - might have a bit of AC on top though. > > (nice to have you back Dave - glad you're well) > > The impedance stuff is just nomenclature. Impedance to my > mind was just a > catch all term for all kinds of > resistive/capacitive/inductive "quantities". > Maybe we should rename it "hindrance" to keep everyone happy. Why are we making this difficult? resistance is for DC, impedance for AC - its all in the textbooks - no need to redefine. > > As for the audibllity of HF, I recall reading something in > Stereophile (well > dammit, you can't get SP any more, can you) about the ear having a > *separate* mechanism which could respond to transients/pulses. > > Anyway, let's not forget the issue of rise time. Many people > forget that > frequency response aka fourier transform is only appropriate for > repetitive/periodic signals. As I hate most dance music, I'd > like for my > tweeters to go skyward. Incidentally, HiFi Choice (I really > have to trawl > through *everything* to find anything interesting these days) had an > interview with Morecroft of DNM who claimed to have developed > a ribbon that > was flat to 200kHz and had detectable output at 1Mhz. Although how he > measured all this was unmentioned (strangely). Was this Morecroft or Max Townsend cause from a post on another forum..... "I've been involved recently with a couple of products with my old friend Max Townshend. One that Chris mentioned is the new SuperTweeter which while I think Max was a little over enthusiatic when he told Chris that its high end -3bd point was 1 Mhz it is still an superb product. For the record the - -3db point relative to 20Khz is in fact 300Khz which is still pretty amazing. Incidentally the measurement was done by running two tweeters back to back and scoping the output friom the second tweeter (taking into account losses etc)." or could be both of them of course :-) regards, Stephen Robinson (a LJ) em@il: mailto:stephen@izzy-wizzy.com www: www.izzy-wizzy.com/audio ========================================================================= From: "Emile Sprenger" Subject: RE: [JN] 1Mhz Tweeters,DC/AC, impedance, bandwidth etc etc Date: Thu, 20 Sep 2001 13:20:57 +0200 Source: Sound Digest Archive v02.n980 > Mesh plate magnetrons, anyone? I'm still searching a DHT klystron ... ========================================================================= From: "Emile Sprenger" Subject: [JN] 1 million copy-protected CDs released Date: Tue, 21 Aug 2001 00:06:00 +0200 Source: Sound Digest Archive v02.n951 "Israeli security company Midbar said Wednesday that it released 1 million copy-protected CDs in the European market and plans are in discussion for entry in the U.S. market. Midbar said the CDs are protected by its technology, dubbed Cactus Data Shield, which prevents potential copyright pirates from illegally reproducing the content." http://news.cnet.com/news/0-1005-200-6818539.html?tag=mainstry ========================================================================= From: John Levreault Subject: [JN] Re: 1 tube amps Date: Sat, 29 Jan 2000 17:15:23 -0500 Source: Sound Digest Archive v02.n424 tube@jump.net wrote: > There are some interesting possibilities out there. A few are: > > Vin Rp Wp Wout Type > 6AG9/6AL9 2.07 1.63K 9.0* 1.80 Pentode > 6AK10 2.36 2.50K 6.0 1.20 Triple-triode > 6FQ5A 1.90 3.15K 5.0 1.00 Double-triode > 6HK5 1.67 2.50K 4.6 0.92 Double-triode > 6HQ5 1.67 2.70K 5.0 1.00 Double-triode > 6J4 2.16 2.25K 4.5 0.90 Double-triode > 6KN8 2.08 1.40K 4.4 0.88 Double-triode > 6MN8 2.14 1.83K 9.0 1.80 Triple-triode > 7KY6/11HM7 2.27 1.35K 6.8* 1.36 Pentode > 12HG7 2.07 1.42K 6.5* 1.30 Pentode > 417A/5842 2.46 1.80K 4.0 0.80 Triode > 417A * 2 1.74 0.90K 8.0 1.60 Two 417A's in parallel > 437A 1.58 1.00K 7.0 1.40 Triode > 6442 2.75 3.03K 8.0 1.60 Planar triode > 6688 * 2 1.52 0.85K 7.4 1.48 Two 6688's in parallel > 7788 1.30 0.98K 5.8 1.16 Pentode > 7911 2.08 2.32K 6.5 1.30 Planar triode > 7913 1.25 2.50K 5.5 1.10 Planar triode I don't mean to rain on the parade here, because this is a very interesting analysis that took a lot of time. But there are some second order effect that you need to consider, using the characteristic curves. The big caveat is that you must also consider the bias voltage. For example, the 417A/5842 biases at Egk of about -1.6V for 150V/20ma, and increasing the current will require even less bias. You're simply not going to get 2.46Vrms Vin into the grid without some kind of help to overcome the grid current, assuming the grid doesn't get toasted in the process. Regarding the 417A, I recall that Lynn Olson raised the issue of grid distortion when the Egk gets less than -0.5V. This means that you're limited to about 1-1.2V peak into the grid. Even if you were to drive the grid all the way to Egk = 0, with a mu of ~45, this means you'll get about 1.6 x 45 = 72Vpk at the output. Converting to sinewave by dividing by sqrt2, we get about 50Vrms. Put this into a load of ~5.4K (3x the 1800ohm rp) gives about 0.5W of output power, albeit ignoring the grid distortion. This is not an insignificant amount of power, and many have been very pleased with the results. I suspect you can push the 437 a bit harder, and its ~1K rp will allow a lower load impedance. I was just looking at the curves for some Russian 6C45pi's that I saw for sale over on ebay and, ignoring the grid current problem alluded to above, I think you might get about 800mw+ into 3.3K at a bias point of 195V/40ma. JL ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] Re: 1 tube amps Date: Sat, 29 Jan 2000 18:16:48 EST Source: Sound Digest Archive v02.n425 In a message dated 1/29/00 3:19:39 PM US Mountain Standard Time, jlevro@mediaone.net writes: > I don't mean to rain on the parade here, because this is a very interesting analysis that took a lot of time. But there are some second order effect that you need to consider, using the characteristic curves. The big caveat is that you must also consider the bias voltage. For example, the 417A/5842 biases at Egk of about -1.6V for 150V/20ma, and increasing the current will require even less bias. You're simply not going to get 2.46Vrms Vin into the grid without some kind of help to overcome the grid current, assuming the grid doesn't get toasted in the process. ________ Greets, The SV83 using a AA inline to the grid (-1.6V) for 200V/~50 mA using the parafeed OPT primary CT as a UL thru 2K to the screen. For a bit of headroom, I added 10 ohms bypassed by 5 each 1000uF 6.3V caps under the cathode. This reduced the current to 45 mA at approx 215V. (Unregulated B+ supply). Bias leaps up to -2.15V. The retard coil shunt load (parafeed) theoretically allows 2 * B+ swing thru the AC only OPT. In real use, it lets a lot of music out. No rain in sunny Phoenix :) Just smog (koff koff) Happy Ears! Al B^} ========================================================================= From: tube@jump.net Subject: Re: [JN] Re: 1 tube amps Date: Sat, 29 Jan 2000 23:52:51 -0600 Source: Sound Digest Archive v02.n425 Paul de Raymond Leclercq wrote: > Interesting; > I have tried 6J4; not exhaustively, because it cannot stand more than 150V > on its anode. It doesn't sound bad and the JAN types I bought here in > England (dirt cheap) are not microphonic - which is more than can be said > for Sylvania's 6J6s! > > There is an error here though: 72v peak does not equal 50v rms. The rule > for voltages is divided by root/2 (2.828). 72v pk-pk therefore, equals > 25.46v rms. (Assuming of course you meant pk-pk!). I think John actually did mean 72 Vpk or peak, not 72 Vpp or peak-to- peak, and 72 Vpk really is 50 Vrms, although you are right that for peak-to-peak voltages, you must divide by 2.828. > There are several others worth mentioning here: > > 6BK7A (but to get the rated mu of 43 you need the run it hard; gm can reach > 9) > 6BQ7A (has anyone ever seen one?) > These are double triodes. > > If you want a single triode, 6AN4 is a corker! I had to import mine from > the US. This is a pretty 7-pin ultra miniature type (same height as a 417). > It has an exposed cathode like 12B4 or 6J6 and therefore looks good lit up > (don't we all?) > > Pa is an amzing 4W, mu is 70 and gm 10. Ra is therefore 7k which is good > value for such gain, and Ca-g is also soothingly low. Yah, I had this one too, but I left it off the list because of its 7K plate resistance. Also, the 6HA6 has 9W available, but needs 2.9 Vrms to get 1W out. Well, there are lots of other candidates, especially if we can use tubes that need a bit more Vin. Fortunately, with tube amps, there is often quite a bit more than 1 Vrms available. > Finally, 6FQ5 is not a double triode; it's a single triode with simila > characteristics to 6GK5. AND the 6HK5, AND the 6HQ5! Sheesh! don't know how I missed all of those. Must be that massive brain-power I like to think I have ... > Paul > triode@bow-tie.org.uk > Well, the main thing is that there are POTENTIALLY many more one-tube amps, and for that matter one-tube drivers for 211's and such, than just the 437A and 7788. As to whether a particular tube can deliver the full potantial power or not, that depends on the voltage limits of the tube. As long as the plate voltage can be raised to a high enough point, full power can be obtained from the tube. But while the voltages of tubes can often be much greater than the "official" specs, I have no idea if the 417A is an example! > > ----- Original Message ----- > From: John Levreault > To: > Cc: ; ; > ; ; dave slagle > > Sent: Saturday, January 29, 2000 10:15 PM > Subject: [JN] Re: 1 tube amps > > > tube@jump.net wrote: > > > > > There are some interesting possibilities out there. A few are: > > > > > > Vin Rp Wp Wout Type > > > 6AG9/6AL9 2.07 1.63K 9.0* 1.80 Pentode > > > 6AK10 2.36 2.50K 6.0 1.20 Triple-triode > > > 6FQ5A 1.90 3.15K 5.0 1.00 Double-triode > > > 6HK5 1.67 2.50K 4.6 0.92 Double-triode > > > 6HQ5 1.67 2.70K 5.0 1.00 Double-triode > > > 6J4 2.16 2.25K 4.5 0.90 Double-triode > > > 6KN8 2.08 1.40K 4.4 0.88 Double-triode > > > 6MN8 2.14 1.83K 9.0 1.80 Triple-triode > > > 7KY6/11HM7 2.27 1.35K 6.8* 1.36 Pentode > > > 12HG7 2.07 1.42K 6.5* 1.30 Pentode > > > 417A/5842 2.46 1.80K 4.0 0.80 Triode > > > 417A * 2 1.74 0.90K 8.0 1.60 Two 417A's in parallel > > > 437A 1.58 1.00K 7.0 1.40 Triode > > > 6442 2.75 3.03K 8.0 1.60 Planar triode > > > 6688 * 2 1.52 0.85K 7.4 1.48 Two 6688's in parallel > > > 7788 1.30 0.98K 5.8 1.16 Pentode > > > 7911 2.08 2.32K 6.5 1.30 Planar triode > > > 7913 1.25 2.50K 5.5 1.10 Planar triode > > > > I don't mean to rain on the parade here, because this is a very > interesting > > analysis that took a lot of time. But there are some second order effect > that > > you need to consider, using the characteristic curves. The big caveat is > that > > you must also consider the bias voltage. For example, the 417A/5842 biases > at > > Egk of about -1.6V for 150V/20ma, and increasing the current will require > even > > less bias. You're simply not going to get 2.46Vrms Vin into the grid > without > > some kind of help to overcome the grid current, assuming the grid doesn't > get > > toasted in the process. > > > > Regarding the 417A, I recall that Lynn Olson raised the issue of grid > distortion > > when the Egk gets less than -0.5V. This means that you're limited to about > > 1-1.2V peak into the grid. Even if you were to drive the grid all the way > to Egk > > = 0, with a mu of ~45, this means you'll get about 1.6 x 45 = 72Vpk at the > > output. Converting to sinewave by dividing by sqrt2, we get about 50Vrms. > Put > > this into a load of ~5.4K (3x the 1800ohm rp) gives about 0.5W of output > power, > > albeit ignoring the grid distortion. This is not an insignificant amount > of > > power, and many have been very pleased with the results. > > > > I suspect you can push the 437 a bit harder, and its ~1K rp will allow a > lower > > load impedance. I was just looking at the curves for some Russian 6C45pi's > that > > I saw for sale over on ebay and, ignoring the grid current problem alluded > to > > above, I think you might get about 800mw+ into 3.3K at a bias point of > > 195V/40ma. > > > > JL > > > > > > ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] Re: 1 tube amps Date: Sun, 30 Jan 2000 06:58:54 EST Source: Sound Digest Archive v02.n425 In a message dated 1/29/00 7:21:23 PM US Mountain Standard Time, rfrancis@glasscity.net writes: > How did you come up with the 2K value twixt screen and OPT center tap? Kismet. Happy Ears! Al B^} ========================================================================= From: tube@jump.net Subject: [JN] Re: 1 tube amps] Date: Sun, 30 Jan 2000 08:59:34 -0600 Source: Sound Digest Archive v02.n425 P. de R. L." wrote: > Maybe I missed something? > > I think 7k ra for mu of 70 is good value; look at all those people who use > 6CG7 and pay lots of money! They get about 8k at best for a miserable mu of > 18 or so; OK I accept it's a differnt job, but horses for courses after > all - and 6AN4 sounds better than 6J4 I think. > > I once tried 6AN4 as a concertina phase-splitter, it sounded very good there > actually - even better than the 3A/167M (=437A) which I also tried! > > Regards, > > Paul Better than a 437A? That's good to hear, since I suspect it's about 20 times less expensive! Anyway, to answer your question, I was mainly trying to list tubes that could be used as an output tube, and with an Rp of 7K, two of these in parallel would need about 14K for the output transformer. Now, that's no different from a 211--a little better, in fact--but I didn't want to list every good tube out there, so I simply cut out those that needed more than 7 Vpp to get 1W out, along with the tubes with a combined Rp > 2.5K or so. In other words, it is a very incomplete list! Phil ========================================================================= From: StepHydro@aol.com Subject: Re: [JN] Re: 1 tube amps Date: Sun, 30 Jan 2000 09:40:35 EST Source: Sound Digest Archive v02.n425 In a message dated 01/30/2000 9: Since these Russian babies are already for sale on ebay Couldn't find them on eBay. Does anyone know of a URL for the tube data? What price are these going for in the US? Cheers/Carron ========================================================================= From: Christian Rintelen Subject: Re: [JN] Re: 1 tube amps Date: Sun, 30 Jan 2000 15:28:25 +0100 Source: Sound Digest Archive v02.n425 John Levreault wrote: > I was just looking at the curves for some Russian 6C45pi's that > I saw for sale over on ebay and, ignoring the grid current problem alluded to > above, I think you might get about 800mw+ into 3.3K at a bias point of > 195V/40ma. Since these Russian babies are already for sale on ebay, they're no longer a secret weapon and I guess it's OK to report that I recently slapped together not a 1-tube but a 1-stage amp (6C45P-E p-p). Push-pull because I had a decent 5.5k PP-OPT at hand and no suitable SE OPT. I'm using a Sowter 8920 1:1+1 input transformer for the phase splitting. The 6C45 are run pretty hard at 195 V (yes, that's 8.7 W instead of the spec'd max 7.8 W dissipation. And yes, I'm very well aware that the manufacturer gives 150 V as max B+.) With 2.2 V neg grid bias (fixed bias with battery to the ct of the input xformer), they draw around 45 mA each. I also tried cathode bias with a 47 ohm resistor bypassed with a BG 4700 uF (which isn't neccessary on a p-p amp with a common cathode resistor, I know). There was no audible difference between fixed and auto bias at the same grid voltages. This amazing little amp produces enough power to run my Blue Thunder speakers full range to more than just loud volumes in a fairly big room! I measured the frequency response -0.1 dB at 20 Hz and + 0.2 dB at 20 kHz. -3dB is at 92 kHz. Distortion at normal loud listening volumes is between 0.17 and 0.4% THD. Haven't been able to measure 2nd and 3rd harmonics, but it sounds good. And yes, I have already ordered a Tango 5k:8 SE OPT to build a 1 tube SE amp with those Russian tubes.... Get them while you can. Christian ========================================================================= From: Christian Rintelen Subject: Re: [JN] Re: 1 tube amps Date: Sun, 30 Jan 2000 15:51:45 +0100 Source: Sound Digest Archive v02.n425 data: http://www.tubes.ru/techinfo/HiFiAudio/6s45pe1.html curves: http://albums.photopoint.com/j/AlbumIndex?u=37049&a=237580 The 6C45 and the 6C15 are identical, the 6C45 is the newer version. It's a very rugged tube with a plate that looks like it could withstand 30 W..... You can get them at http://www.tubes.ru @ approx $6.00 each. I don't know how big the stock is, so you better hurry up! Christian StepHydro@aol.com wrote: > In a message dated 01/30/2000 9: Eastern Standard , rintelen@datacomm.ch writes: > > > Since these Russian babies are already for sale on ebay > > Couldn't find them on eBay. Does anyone know of a URL for the tube data? What > price are these going for in the US? > > Cheers/Carron - -- Christian Rintelen Konzept und Text Dufourstrasse 165 CH-8008 Zurich / Switzerland Voice: +41 1 420 11 55 Fax: +41 1 420 11 57 mailto:rintelen@datacomm.ch ========================================================================= From: blackie Subject: Re: [JN] Re: 1 tube amps Date: Sun, 30 Jan 2000 12:25:32 -0800 (PST) Source: Sound Digest Archive v02.n426 - --- Christian Rintelen wrote: > Since these Russian babies are already for sale on > ebay, they're no longer a secret > weapon and I guess it's OK to report that I recently > slapped together not a 1-tube > but a 1-stage amp (6C45P-E p-p). > bring it to nyNOISE!!!!!!! ===== blackie blackie@tubesville.com www.tubesville.com __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com ========================================================================= From: "J. Gordon Rankin" Subject: Re: [JN] Re: 1 tube amps Date: Sun, 30 Jan 00 23:32:07 -0500 Source: Sound Digest Archive v02.n427 John, >Regarding the 417A, I recall that Lynn Olson raised the issue of grid >distortion >when the Egk gets less than -0.5V. This means that you're limited to about >1-1.2V peak into the grid. Even if you were to drive the grid all the way >to Egk >= 0, with a mu of ~45, this means you'll get about 1.6 x 45 = 72Vpk at the >output. Converting to sinewave by dividing by sqrt2, we get about 50Vrms. Put >this into a load of ~5.4K (3x the 1800ohm rp) gives about 0.5W of output >power, >albeit ignoring the grid distortion. This is not an insignificant amount of >power, and many have been very pleased with the results. Actually what happens is that the grid starts to draw current. Best bet is to use and input tranny or choke load the input to get more the most out of these and the 437! Gordon =====> Wavelength Audio <===== mailto:waudio@cinti.net http://www.WavelengthAudio.com ph.fx. 513-271-4186 USA ========================================================================= From: StepHydro@aol.com Subject: Re: [JN] Re: 1 tube amps...VT Omega??? Date: Sun, 30 Jan 2000 09:36:02 EST Source: Sound Digest Archive v02.n425 In a message dated 01/30/2000 9: Since these Russian babies are already for sale on ebay, they're no longer a > secret weapon and I guess it's OK to report that I recently slapped together not a > 1-tube but a 1-stage amp (6C45P-E p-p). Is this the valve that is being called the VT Omega? Cheers/Carron ========================================================================= From: "Sellek, Grant (TSA)" Subject: [JN] RE: 1X DAC Date: Thu, 13 Apr 2000 15:05:12 +0930 Source: Sound Digest Archive v02.n519 Thanks Carter. Yes it was after reading the Sakura article that I realised my knowledge of CD was insufficient to figure out for myself if this is just a well-done generation-one converter, or if there is more to it. I still don't know. I have just had a quick read of the TNT-audio article and I STILL don't know if 1X = 1983 + quality. Now I will go back over it more closely, but any explanations from the group will be great. Grant Grant Sellek Adelaide, Australia grant.sellek@transport.sa.gov.au - -----Original Message----- From: Carter Hendricks [mailto:carter@i1.net] Sent: Thursday, 13 April 2000 2:22 pm To: Sellek, Grant (TSA) Subject: 1X DAC Grant-- Hi! It took me a couple tries but have you read the translation of the MJ article at: > >For the real scoop on real 1X DACs see www.sakurasystems.com. and maybe look at the schematic url posted in a couple messages lately. --Carter 2222 ========================================================================= From: Dan Marshall Subject: [JN] 200CD Transformer Evaluation Date: Fri, 21 Jul 2000 14:35:06 -0700 Source: Sound Digest Archive v02.n608 Hi All, I received the 200CD output transformer set from Rick Francis and had a look at them. They consist of a small round, phenolic transformer which is good only above 5 kHz, so is not of much interest in the audio band, unless one wishes to triamp. The low frequency transformer is an altogether different matter, a rather beefy unit, about the size of the opts in the Heath EA-2 amplifiers except with about 2/3 the core thickness. They show quite a lot of promise as interstage transformers for tube amplifers. Unfortunately, they are open-frame units and would require end bells, or potting for a nice appearance. They are PP cathode driven in the 200CD oscillator, with series resistors (a couple hundred ohms) and a 600 ohm Tee attenuator on the output. They have three windings, essentially 1:1:1 turns ratio. Two of the windings are used for the PP primary in the 200 CD. The winding dc resistances measure from about 108 ohms to 137 ohms. After experimenting around it was determined that for an IT it seems to perform better if the secondary winding is used as the primary with the two primaries in series for the secondary. The original primaries are labeled as terminals 1&2 and 3&4, and the secondary as 5&6. Two configurations were optimized, PP and SE. The input was into terminals 5&6 with 6 grounded in all cases. In SE connection, it was found that it performs best with the two (now secondary) windings in series with terminals 1&4 joined, terminal 2 to ground with the output taken from terminal 3. Secondary loading, if used, seems to work best across both windings rather than split across the two halves. This is the opposite of most of the cheapie ITs. It is in general less tempermental and better performing than the cheapie ITs. The value of primary driving impedance is rather critical to achieve flat response to 20 kHz w/o overshoot or ringing, and it is possible to achieve this without secondary loading. The optimum source resistance was found to be 1.3k in series with the 600 ohm generator output impedance for a total of 1.9k. This gives just a bit of overshoot which settles right down. With this primary driving resistance it has flat frequency response to 20 kHz, where it starts a very gentle and well-mannered rolloff. A bit less overshoot is attained with slightly greater driving impedance, but the response will be off about 1/2 to 1 dB at 20 kHz. If a bit lower source impedance is used, it needs a bit of secondary damping (to attain good square wave response w/o ringing), to which it responds well. This will extend the high frequency response a bit farther. It may be a bit tricky to get a driver tube with optimum rp, so it would seem reasonable to drive it with a tube that exhibits a bit less than 1.9k rp, then tweak the secondary loading a bit for best squarewave response. It is very well mannered and it doesn't take much secondary loading to tame it quite nicely. If give or take a dB at 20 kHz doesn't upset you, then a driver tube exhibiting an rp in the range of 1.8 k to 2 k should do quite nicely. If a purist, then tweak it a bit. It doesn't perform well with the two secondaries in parallel and it does not work well in the cap-bridged mode, as the winding ratio is not exactly 1:1 from the primary to one secondary, close, but not exact. For PP use, use the same primary connection, join 1&4 for the secondary ct and connect to ground, or bias supply, and take the outputs from terminals 2&3. Separately, these outputs exhibit some ringing, no matter how you terminate the primary, but when they are summed on the scope, the ringing pretty well cancels out. It is not a large ring, so this ought to be OK. A driving impedance of 2k total is optimum. The summed outputs exhibit a small amount of ringing, but a very small amount. There is a rather narrow pre shoot spike on the trailing edge, but it is up fairly high in frequency and is not likely to be excited by anything in the audio band. In the PP mode it is flat to 30 kHz. One half of a 6BL7 ought to be a good driver tube. In either configuration, the low frequency response is quite excellent, being flat on down to well below 10 Hz when driven by a 2k source impedance. In the SE configuration (~1:2), I measured about 110 volts PP at 10 Hz with no evidence of core distortion. It was being driven by an operable 200CD at its maximum output voltage. So, at 20 Hz, you should have the capability of driving most lo-mu triodes. I did not examine its ability to handle dc current. It does not have an air gap and the core is varnished, so I didn't try to take it apart, though this might be possible. It may handle some dc. Perhaps I will look at this later. All in all, I was quite pleased with its performance and would not hesitate to incorporate it into an amplifier design. Examining the 200CD transformers for their suitability as interstage transformers was a good idea Rick. Dan Marshall ========================================================================= From: =?iso-8859-1?Q?Tom_Andr=E9_Hansen?= Subject: [JN] 205 ... Date: Sun, 11 Mar 2001 03:06:07 +0100 Source: Sound Digest Archive v02.n830 Intrigued by their shape; I might go about something I seldom do. Buy stuff because of their look, and not their performance. New Sensor have the (in)famous Allmusic tubes. I've read much crap, but some like them. It's mostly that cool looking 300B I've found thoughts on. Does anybody on this list have something to say about Allmusic? Why I wrote (that might be a little woolly yet). The tennis ball 205D I know something about, but the 101D, or 102D? Haven't found much about those two (also two funky looking creatures as far as I have understood). So info on 101D/102D, and Allmusic in general, would be greatly appreciated. If I'm really lucky I person who use the 101D/102D/205D will answer this :) PS! I do of course hope that these tubes perform very well -- if I am to buy some Wimbledon globes. - -- Tom André Hansen http://cgiperlsite.virtualave.net ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 205 ... Date: Sun, 11 Mar 2001 12:45:31 EST Source: Sound Digest Archive v02.n830 - --part1_96.112f6f65.27dd13bb_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit dunno 316A is a fine sounding tennis ball, and cheap, to boot :) Ears! Al B^} - --part1_96.112f6f65.27dd13bb_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit dunno

316A is a fine sounding tennis ball, and cheap, to boot :)

Ears!

Al   B^}

- --part1_96.112f6f65.27dd13bb_boundary-- ========================================================================= From: =?iso-8859-1?Q?Tom_Andr=E9_Hansen?= Subject: Re: [JN] 205 ... Date: Mon, 12 Mar 2001 00:54:58 +0100 Source: Sound Digest Archive v02.n830 316A? Why not ... I was thinking about using the 205D as a output tube, but I changed my mind. Though looking at the data of the 102D tube -- that might be an interesting tube to play with (preamp maybe). The 316A sure is a sturdy tube. Found this while looking for info on it "Bryant: When did you first learn the then-secret subject, what we call radar? Pound: On the occasion of my visit in 1940. They had an operating radar that they had developed on their own initiative. Bryant: Aimed toward a Navy application? Pound: Well, no. It was for research. Well, it was supposedly a ground-based system or a ship based. It used two tapered horns with apertures about 4 x 6 feet that were mounted on a big rotatable platform that they had built up on the roof. I'm not sure if that was finished when I first came, but we had it running the next year. It was a 50 cm system, and it used a Western Electric 316A doorknob tube. They hit it with 2500 volts pulses. It was a 300 volt tube. The input pulse power was two kilowatts." Wow :) - -- Tom André Hansen http://cgiperlsite.virtualave.net ========================================================================= From: Adnan Arduman Subject: [JN] 20 Audiophiles and Their Sanctuaries Date: Mon, 26 Apr 1999 10:40:57 +0200 Source: Sound Digest Archive v02.n131 Hi All, If you wish to have a look, there are now 20 entries in "My Friends' Systems" section of my web site: http://www.arduman.com/aa Other updated sections are "Links" and "Updated CD's". Any views are appreciated. Many thanks in anticipation. Adnan Arduman visit my personal "NUANCE & FLUENCE" web site: http://www.arduman.com/aa tel: +90-216-310 44 70 (w) fax: +90-216-343 42 01 e-mail: adnana@turk.net ========================================================================= From: Adnan Arduman Subject: Re: [JN] 20 Audiophiles and Their Sanctuaries Date: Tue, 27 Apr 1999 11:31:54 +0200 Source: Sound Digest Archive v02.n132 Hi Bart, Thanks for the suggestions which are noted. In fact the speaker I'm looking for is for my future project (which is going to be an integrated 300B SE). Therefore I have to look for something more efficient than the Response 3.5's (89 dB/m/W). I do not have any bias for any type of speakers but I'm just very curious to hear a Lowther based one as I could not succeed to acheive that for such a long time. Maybe I'll hate them (I hope not!) at the end of the day but I still wish to hear at least one. I hope Tom Ronan will help me in this when I'll be in Chicago at mid May. I promise to write back what I think. Thanks again, Adnan >If you are used to the Responses, I wouldn't hold out too much hope for a >Lowther full-range. Maybe as a mid-range horn augmented by a sub and >possibly also a super-tweeter. > >Maybe a TAD horn plus a JBL in an Onken enclosure?? > >I am using Hyperwhamodynes and also Tannoy 15 inch. Neither is totally >satisfactory but something along the 'whamo's idea (big TQWP with 4 drivers >+ tweeter) with better drivers might just do it. > >With the 845's you only need 92 - 96 db efficiency. > >Cheers, > >Bart visit my personal "NUANCE & FLUENCE" web site: http://www.arduman.com/aa tel: +90-216-310 44 70 (w) fax: +90-216-343 42 01 e-mail: adnana@turk.net ========================================================================= From: Adnan Arduman Subject: Re: [JN] 20 Audiophiles and Their Sanctuaries Date: Tue, 27 Apr 1999 11:36:57 +0200 Source: Sound Digest Archive v02.n132 Lance, >For some strange reason, I wasn't able to access your site tonight, but >I've been following you work on and off since January. I think it's >excellent and I've recommended that we do something similar with our Web >page. We're in the process of collecting photos/write-ups on members' >systems to get things going. Many thanks for your encouraging comments. I hope you will try to access one more time today. >I'll keep you informed of our progress. I'll be very pleased if you do. Sincerely, Adnan visit my personal "NUANCE & FLUENCE" web site: http://www.arduman.com/aa tel: +90-216-310 44 70 (w) fax: +90-216-343 42 01 e-mail: adnana@turk.net ========================================================================= From: Adnan Arduman Subject: Re: [JN] 20 Audiophiles and Their Sanctuaries -Reply Date: Tue, 27 Apr 1999 18:34:54 +0200 Source: Sound Digest Archive v02.n133 Hi Ralph, Thanks for your input. As I am a total ignorant on the subject of Lowthers, I'm copying this e-mail to Tom Ronan. I hope he will have the setup you mention. I was also planning to write to Tom directly and I would like to ask him to accept my apologies for such an indirect first contact. Your 2 cents are on the way. Adnan >Hi Adnan, > >You said : > >>In fact the speaker I'm looking for is for my future project (which is >>going to be an integrated 300B SE). Therefore I have to look for something >>more efficient than the Response 3.5's (89 dB/m/W). I do not have any bias >>for any type of speakers but I'm just very curious to hear a Lowther based >>one as I could not succeed to acheive that for such a long time. Maybe I'll >>hate them (I hope not!) at the end of the day but I still wish to hear at >>least one. I hope Tom Ronan will help me in this when I'll be in Chicago at >>mid May. I promise to write back what I think. > >Bart said : > >>If you are used to the Responses, I wouldn't hold out too much hope for a >>Lowther full-range. Maybe as a mid-range horn augmented by a sub and >>possibly also a super-tweeter. >> > >Don't make up your mind until you hear Lowthers with the Oris front horns >and a good subwoofer. It's a different sound than you are probably used to, >but one I think that you will like very much. The top end lacks for >nothing in these >horns. Back horns are not nearly as good. You won't hate front horn Lowthers >I can assure. > >Make sure Tom has the Oris horns with a good subwoofer and the phase >extenders installed from Bert Doppenberg before you go to visit him. He's >currently using a 46 amp (with 1.25 watts!), but the Lowthers are not hurting >for power at all. > >BTW, I am also using a very simple 5842 + 46 amp on my Lowthers now. > >My 2 cents, > > - Ralph visit my personal "NUANCE & FLUENCE" web site: http://www.arduman.com/aa tel: +90-216-310 44 70 (w) fax: +90-216-343 42 01 e-mail: adnana@turk.net ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 20Hz-20,000Hz, +/-3db .. but at what level? Date: Sat, 10 Jun 2000 22:46:48 EDT Source: Sound Digest Archive v02.n574 Greets! Your listening room is also affected by level. So are your ears. It is all hopeless :) The perfect anechoic chamber gives accurate, repeatable measurements which are not much help in tuning your real world listening room. I just keep tweaking everything in my listening room. I know I cannot reproduce my fine sound in some other room. I do not care. I am retired, I do not have to. Audio Anarchy Lives! I also know I could create fine sound in another room, but NOT the SAME fine sound. This is simple empirical experience. It won't sell in mass quantities, Thank God. Happy Ears! Al B^} ========================================================================= From: "Sellek, Grant (TSA)" Subject: [JN] 20Hz-20,000Hz, +/-3db .. but at what level? Date: Sun, 11 Jun 2000 11:20:40 +0930 Source: Sound Digest Archive v02.n574 An interesting post off a local newsgroup. Reminds me of some of Tom Dunker's wonderful posts a few years back on the advantages of a highly efficient speaker. Remember them? Grant Sellek, Adelaide, Australia Philip Vafiadis wrote in message news:<15p05.13011$N4.471695@ozemail.com.au>... > Very good observation. This is a very complicated issue...most manufactures > 'measure' at 1 watt...however 'measure' might be somewhat of an > overstatement with regard to many performance claims. Some issues as > follows: (As usual this is simplified 'plain English explanation'..those > readers with higher level Tech knowledge should be able to fill in the gaps) > > 1) > Displacement related compression. > > Most woofers only move proportionately to their input signal for only a part > of their total travel....a typical 210mm woofer might move a total of > +/-10mm (20mm Overall) but it's 'linear' travel may only be +/-3mm (overall > 6mm). As the volume level is increased a point will come when displacement > limited compression is encountered. ie As you wind up the volume the bass > will not increase as much as the treble in a two way system....This will > result in a frequency vs amplitude response that stays the same up to a > point and then changes as compression 'sets in'. The 210mm woofer in our > DC-X moves 25mm overall and, if I remember right, 11mm linear....that's > almost 6dB more volume potential before obvious compression sets in. > > 2) > Temperature related compression. > > The electro-mechanical model developed around loudspeakers are not too bad > these days...programs like LEAP and others can predict the outcomes of these > effects reasonably reliably (not exactly though). If you make a quick > measurement the voice coil does not get too hot...if you run the speaker at > full power for 10min then repeat the test some differences will be expected. > Not only does voice coil resistance change when hot (and consequently driver > Q) but also the magnetic system may behave differently. For those who are > not sure how much of an issue temperature is in a loudspeaker driver should > touch a 45W light bulb...Ouch!!! now imagine that heat going into your > speakers for, say, half an hour....even a big lump of metal (like a speaker > motor) will get quite warm...and that's just with 45Watts continuously. PA > people usually only consider 'large signal' performance and almost disregard > low level performance as their equipment is almost always driven VERY hard. > > 3) > Measurement inaccuracies > > This will come as a big surprise for many readers .... VERY few speaker > manufactures have facilities that allow them to measure accurately. Most, > including us, use FFT or MLS based measurement techniques as that rely on a > mathematical sequence of noise fed to a speaker under test that is picked up > by a mic and processed by a computer...these software based systems are very > cheap... starting at around $1,000 and going up to around $50,000. Despite > the great 'power' available with these new tools they are also limited in > normal labs. These tools appear attractive as it is possible to > differentiate the direct signal from the speaker and the reflections off the > lab walls and floors etc....the problem is that as you start to 'gate' out > the reflection the maths becomes less reliable at lower frequencies.....the > shorter the time period the less reliable the low frequency > measurement......There is NO substitute for anechoic measurements...VAF is > one of the few speaker companies in the world that has a wide frequency > range anechoic chamber...ours has 1.5 metres of foam on the walls! > > 4) > What distance to measure at. > > Most frequency response measurements are taken at around 1 Metre, while > 'sort of' a standard distance, it is a 'stupid' distance.....almost no-one > listens at 1 Metre. VAF measure at between 2 Metres and 3.5 Metres depending > on the speaker...statistically most people listen at between 2.5 M and 3.5M > from their speakers. > > With regard to your question, "Is there any point in comparing freq > responses claims between manufacturers?" A little...but not much > point...Phase response, Stored energy (cumulative Spectral Decay), power > response (total speaker radiation) etc should also be compared.......My > guess is that fewer than 10% of speaker manufactures would be in a position > to reliably make these measurements.... most published measurements are VERY > flawed....When you are comparing figures find out what facilities the > manufacturer has...don't rely on the sales 'blurb'. At VAF we go to a > **LOT** of trouble to ensure our measurements are valid...probably why our > speakers were chosen for the worlds largest and most sophisticated > electro-acoustic system or why Telstra called us when they needed acoustic > help with their new WayPhone. > > Best regards > Philip Vafiadis > VAF Research Pty Ltd > www.vaf.com.au > > > > scott wrote in message > news:3941ECEF.14FACBA3@bigpond.net.au... > > Just reading some speakers specs and comparing manufacturers claims for > > frequency response. > > > > Most of them quote figures like '30Hz to 20kHz +/- 1.5dB' or sometimes > > the +/-3db point. > > > > At what output level is this measured? If it's done at very low volume > > levels, would that make it easier to claim a very wide, flat frequency > > response? If it's done at high volumes, what does that imply about the > > lower volume levels? > > > > Is there any point in comparing freq responses claims between > > manufacturers? Or is this a bit like power output ratings? > > > > Mr Vaf might be able to answer this one (not picking on their claims > > though...) > > ========================================================================= From: Thomas Dunker Subject: Re: [JN] 20Hz-20,000Hz, +/-3db .. but at what level? Date: Mon, 12 Jun 2000 17:25:00 +0200 (CEST) Source: Sound Digest Archive v02.n576 On Sun, 11 Jun 2000, Sellek, Grant (TSA) wrote: > An interesting post off a local newsgroup. Reminds me of some > of Tom Dunker's wonderful posts a few years back on the > advantages of a highly efficient speaker. Remember them? > Grant Sellek, Adelaide, Australia Yeah, I remember them (...) Anyone who can read French should obtain a copy of Jean Hiraga's "Les Haut-Parleurs", which has a lot of hard to find information (a lot of graphics too) on dynamic nonlinearity phenomena in speakers. A lot of hard to find information on speakers, period. It is without a doubt the best single publication on speakers I have come across. Unfortunately I don't read French very well, but maybe OCR scanning and Babel Fish...? Most of the noteworthy distortion in speakers has been well researched and documented. Some of the distortion phenomena were anticipated before practical loudspeakers were a fact, and many of them are still largely ignored. I don't really have a lot to add to the posts I wrote a couple of years back. I already know the challenges well enough to keep me preoccupied a few lifetimes. I'd start with my own bottom line: Nearly all the nonlinear distortion in electrodynamic speakers increases by proportion to the "signal", whether input power (temperature), diaphragm/suspension excursions, modulations of the magnetic field etc. These mechanisms cause dynamic compression, like a thermal/mechanic dynamics compressor, and along with compression, amplitude dependent phase and frequency response changes, interaction with crossovers (if passive) and amplifier, and more nasty things than I can remember off the top of my head. Personally, I believe the "brute force" approach to be the most effective (and least profitable), since ALL electrodynamic speakers possess the same tendency to distort more as the signal amplitude increases. When input power and diaphragm excursions decrease, so does the distortion. To make up for the loss of acoustic output, it is necessary to explore efficient speakers. It seems that a lot of people have stubled across horns and other low-distortion high efficiency speakers merely because they happened to like low power amps. This is fine by me, but I have focused on the intrinsic low distortion of such speakers. Conversely, since amp power got so cheap way back half a century ago, nobody feels that they "need" efficient speakers anymore, wrongly believing that the only thing about efficient speakers is the efficiency. Efficient speakers are efficient for good reasons: Efficient motors and efficient radiators. Less stress, period. They sound that way, too, if properly designed. It's been quiet from my corner for a long while. The audio hobby has been kind of dormant lately, but I'm beginning to get the itch again... I used to build stuff at a shop at the tech college, but now it's a bit too far off that I can go there frequently, so part of the summer's plans is to get a workbench here at home so I can get some tings done again, every time I have a few odd hours to spare. I grew so frustrated with the lack of more or less creative hobby activities that a copule of weeks ago I went out and bought myself another hobby. I have not played an instrument in years (trombone in the school band AGES ago) and don't even sing in a choir anymore and I resolved that I want to learn to play an instrument. They say it's never too late... I've tried the trombone, recorder and guitar, but it was never that much FUN. Then, for the past few years I've listened to a lot of Jethro Tull and grew increasingly intrigued with the flute. I decided I wanted to buy a flute, and so I did, a couple of weeks ago. A used Yamaha YFL-22S, an old student model similar to the current YFL-221S. I took it home, and the minute I got some clean tones out of it, I was hooked. Wow, what FUN to play! So I play the flute now as often as I can, trying to reteach myself reading notes and playing children's tunes. When I have the time and money I will take some lessons. What preoccupies me even more these days is my new girlfriend, who I met on New Year's Eve. When I'm not at work, I spend a lot of my time with her, having the greatest time. She's fun, cute, smart and lovely and kind and the best friend I've ever had. I know I've found "the one". I mean, this time I just *know* - and so does she. Eventually I hope to wipe the dust off some of my unfinished projects and probably to get started with something new. And to whoever is going to Ĺrhus this summer, I'll be there... Still tuned in Tom - ------------------------------------------------------------------------ _/\_ Thomas Dunker \ The Horn Speaker Home Page: / \ P.O.Box 2811 \ http://invalid.ed.ntnu.no/~dunker/horns.html | | 7002 Trondheim \ | | NORWAY \--\ "Those with head above water \____/ dunker@omegav.ntnu.no \ see only the tip of the iceberg" |||| phone: (+47)73911068 \ (Gene Dalby) - ------------------------------------------------------------------------ ========================================================================= From: "Le Cleac'h J.-M." Subject: Re: [JN] 20Hz-20,000Hz, +/-3db .. but at what level? Date: Tue, 13 Jun 2000 13:59:46 +0200 Source: Sound Digest Archive v02.n577 - ---------- > De : Thomas Dunker > A : Sellek, Grant (TSA) > Cc : 'Sound Practices' > Objet : Re: [JN] 20Hz-20,000Hz, +/-3db .. but at what level? > Date : lundi 12 juin 2000 17:25 Thomas Dunker, > and grew increasingly intrigued with the flute. I decided I wanted to buy > a flute, and so I did, a couple of weeks ago. A used Yamaha YFL-22S, > an old student model similar to the current YFL-221S. I took it home, and > the minute I got some clean tones out of it, I was hooked. Wow, what FUN > to play! Wow!! I never could emit a single note (pure tone or distorted) with a flute (and have good nails, that's why for me the instrument is electric guitar)! > What preoccupies me even more these days is my new girlfriend, who I met > on New Year's Eve. When I'm not at work, I spend a lot of my time with > her, having the greatest time. She's fun, cute, smart and lovely and kind > and the best friend I've ever had. I know I've found "the one". I mean, > this time I just *know* - and so does she. > And to whoever is going to Ĺrhus this summer, I'll be there... Did she will be there to? Too bad I am invited (from long time so I couldn't say no that time) in Corsica and cannot come in Arhus... Best regards, Jean-Michel Le Cleac'h, Paris, France ========================================================================= From: "Thomas Sylvester" Subject: Re: [JN] 20k tubes Date: Fri, 23 Mar 2001 07:52:46 -1000 Source: Sound Digest Archive v02.n840 How about 801A/VT62? >>> Buschmann 03/22/01 10:08PM >>> t may i stress your nerves again? it is still the transformer pre - opt is 20k/600 ohm, tube is 76 as anode follower. any other candidates? with a little more uuumphh, eventualy?? a ========================================================================= From: Buschmann Subject: [JN] 20k tubes Date: Fri, 23 Mar 2001 09:08:07 +0100 Source: Sound Digest Archive v02.n840 thank you sirs, for your answers, concerning the sound of batteries..i have to experiment.. may i stress your nerves again? it is still the transformer pre - opt is 20k/600 ohm, tube is 76 as anode follower. any other candidates? with a little more uuumphh, eventualy?? and ,by the way: what to do with a pair of ev sp 8?? thanks jörg ========================================================================= From: Joe Roberts Subject: [JN] $20/pr xfmrs SOLD OUT-tnx! Date: Mon, 05 Jul 1999 09:51:26 +0000 Source: Sound Digest Archive v02.n194 ========================================================================= From: "Paul De Raymond Leclercq" Subject: Re: [JN] 211 vs 845 vs 805 Date: Fri, 6 Jul 2001 10:06:34 -0700 Source: Sound Digest Archive v02.n921 Hello. I doubt that this is a viable scheme. First the operating points: typical bias on a 211 is about -65V; with the 845 it would be around -200 - 250V and with the 805 perhaps 0 or -10V. This shows the different characters of these three valves. Considerable re-design would be necessary Wavac, I believe has made 805 amplifiers, but the the valve is designed as a Class B/C transmitter and is intended to be driven with real power. You would need a driver transformer 845 was designed to be an audio valve and modulator. This and its rarity explain why it is now so costly. It has very low mu (compare mu of 3 with the 805's 140!). Here you have traded driving with Power for driving with Voltage. The different characteristics of these types dictate the type of output transformer needed. Assuming that these amplifiers are single-ended, the primary impedance of the 211 OPT is probably about 10k. With 845 you would probably be looking at 4 - 5k. Finally I might add that I built a p-p amplifier using 211s. The output transformer (I now realise) should have been 20k a-a (which would probably make it not hi-fi). I was using 7k and got 15W for considerable expenditure of power!. I then changed to 845s; heavily modifying the driver stage to deliver the necessary volts at low output resistance (to drive the capacitance of the 845). I then got 50W. The end of this story is that I then converted to triode-strapped 813s. These are almost as easy to drive as 211, but have anode resistance similar to 845. A 7k (p-p) transformer suffices (with 850V on the anodes) and I get still more power - about 60W. I hope that some of this helps. Best wishes Paul Leclercq - ----- Original Message ----- From: Snoopy To: Sent: Thursday, July 05, 2001 9:18 PM Subject: [JN] 211 vs 845 vs 805 > Hi, > > I have the chance of buying a pair of chinese-made 211 se monoblocks. > Each monoblock is using one 6sn7, one 6sl7 and one 211. I am wondering if > it can be easily adapted to use 845 or 805 instead. > > 1. For se design, what's the difference between 211 and 845 in terms of > sound quality, operating points and power output? > > 2. How about the difference between 845 and 805? > > 3. Is there any se or pp schematics using the 805? Is the 805 suitable > for audio? > > I have a pair of G.E. 211 acquired from Edward Billeci long ago. I know > that vintage NOS 845 is expensive, but my friend can offer some United 805 > to me at a reasonable price. Quice interesting to know that the plate of > 805 is at the top of the tube. > > Any advice/information is greatly appreciated. Thank you in advance. > > Best Regards, > > Tung-cheung MA > HONG KONG > 6 July 2001 > ========================================================================= From: "Snoopy" Subject: [JN] 211 vs 845 vs 805 Date: Fri, 6 Jul 2001 12:18:03 +0800 Source: Sound Digest Archive v02.n921 Hi, I have the chance of buying a pair of chinese-made 211 se monoblocks. Each monoblock is using one 6sn7, one 6sl7 and one 211. I am wondering if it can be easily adapted to use 845 or 805 instead. 1. For se design, what's the difference between 211 and 845 in terms of sound quality, operating points and power output? 2. How about the difference between 845 and 805? 3. Is there any se or pp schematics using the 805? Is the 805 suitable for audio? I have a pair of G.E. 211 acquired from Edward Billeci long ago. I know that vintage NOS 845 is expensive, but my friend can offer some United 805 to me at a reasonable price. Quice interesting to know that the plate of 805 is at the top of the tube. Any advice/information is greatly appreciated. Thank you in advance. Best Regards, Tung-cheung MA HONG KONG 6 July 2001 ========================================================================= From: "Sellek, Grant (TSA)" Subject: RE: [JN] 211 vs 845 vs 805 Date: Fri, 6 Jul 2001 14:09:12 +0930 Source: Sound Digest Archive v02.n921 A 211 is much easier to drive than an 845. The 6SN7/6SL7 front end of the 211 amps will not drive an 845. A significant redesign of the front end is recommended: at the minimum you *might* get away with adding a step-up IT to drive an 845, but this could not be determined without some familiarity with the 211 amp's topology and operating points. Recommendation: 211 amps can be very beautiful -- better to try to optimise the amp as a 211 amp. Grant Grant Sellek, Adelaide, Australia - -----Original Message----- From: Snoopy [mailto:tcma@netvigator.com] Sent: Friday, 6 July 2001 1:48 PM To: sound@io.com Subject: [JN] 211 vs 845 vs 805 Hi, I have the chance of buying a pair of chinese-made 211 se monoblocks. Each monoblock is using one 6sn7, one 6sl7 and one 211. I am wondering if it can be easily adapted to use 845 or 805 instead. 1. For se design, what's the difference between 211 and 845 in terms of sound quality, operating points and power output? 2. How about the difference between 845 and 805? 3. Is there any se or pp schematics using the 805? Is the 805 suitable for audio? I have a pair of G.E. 211 acquired from Edward Billeci long ago. I know that vintage NOS 845 is expensive, but my friend can offer some United 805 to me at a reasonable price. Quice interesting to know that the plate of 805 is at the top of the tube. Any advice/information is greatly appreciated. Thank you in advance. Best Regards, Tung-cheung MA HONG KONG 6 July 2001 ========================================================================= From: Grover Gardner Subject: Re: [JN] 211 vs 845 vs 805 Date: Fri, 06 Jul 2001 17:04:00 -0400 Source: Sound Digest Archive v02.n921 Paul De Raymond Leclercq wrote: > > Hello. > > I doubt that this is a viable scheme. > > First the operating points: typical bias on a 211 is about -65V; with the > 845 it would be around -200 - 250V and with the 805 perhaps 0 or -10V. > > This shows the different characters of these three valves. Considerable > re-design would be necessary Yes, the tubes are very different in terms of bias voltage and drive requirements, but the 845 only needs -150 volts bias in Class A at 1200VDC. Still that's a hefty difference. The 845 also has a mu of 8, I believe. Sonically, I've played with all these tubes a bit, the 845 most of all. I like its deep, weighty sound and warmth. The 211 is cooler and sweeter but a bit veiled for my tastes. Nonetheless there have been a lot fine, musical amps built with this tube. You can also drive the 211 into A2, which you cannot do with the 845, so the 211 can approach good power levels with the right circuit. The 805 wants positive grid bias and so is difficult to master. The sound is *quite* different from either of the other two. Taught, clean, analytical, but also musical. In the right hands I suspect it can sing mightily, combining the qualities of the 845 and the 211. In the wrong hands (like mine) you can quickly get into trouble with grid-current issues, distortion, etc. :-) Not for beginners! For Class A at about 1200VDC, the same output tranny should work for either the 211 or 845, 10K being the standard in most designs. The 813 in triode is very interesting, as Paul points out. It combines the deep sound of the 845 with a lighter, faster approach and is easier to drive. They are readily available, going especially cheaply at hamfests and on eBay. I've dropped it into a number of my SE 845 circuits, lowering (or is it raising?) the bias voltage to accomodate it. It works quite well. There is an issue of a slightly peaky, edgy sound to the highs that I've never quite gotten past, sort of what you'd expect from a triode-wired pentode, if you know what I mean. I haven't spent sufficient time playing with it to see if I can get rid of it. Other than that it's a lot of fun to play with. You could probably drop it into a 211 circuit with appropriate bias adjustment and get a taste of the warmer, 845-like sound. - -- Grover Gardner groverg@postoffice.att.net Visit my web site at http://home.att.net/~groverg/homepage.htm ========================================================================= From: Richard C Nevill Subject: Re: [JN] 211 vs 845 vs 805 Date: Fri, 6 Jul 2001 23:25:02 -0300 (ADT) Source: Sound Digest Archive v02.n921 Okay, Being new to this tube stuff I have a pair of RCA 811A's ( Jeremy E. didn't you want them?), a single GE DR-811 and a couple of 866's, one globe and the other coke bottle. So besides the big B+'s these need are they any good as audio tubes? Seeing in the subject 800 series tubes I thought I would ask. I believe I read somewhere that during Desert Storm the SS radios the US was using had problems with the sand and they dug out all their old tube stuff that used 811's. After that no problems Well, cheers gang Richard Nevill ========================================================================= From: "Paul De Raymond Leclercq" Subject: Re: [JN] 211 vs 845 vs 805 Date: Fri, 6 Jul 2001 23:36:59 -0700 Source: Sound Digest Archive v02.n921 Hello. > but the 845 only needs -150 volts bias in Class A at > 1200VDC. Still that's a hefty difference. I have just had a look at the data for 845. At 1.2kV and -150V, the valve would be passing about 135mA, i.e. 162W - more than double its 75W Pa limit. At 1.2kV you would need bias of about -180V to run 63mA which would give you 75W Pa. > > The 845 also has a mu of 8, I believe. I was wrong too! It is 5.3 > There is an issue of a slightly peaky, edgy sound to the highs that I've never quite gotten past, sort of what you'd expect from a triode-wired pentode, if you know what I mean. > -- This is very interesting; when I changed from 845s to 813s (at 980V) the first thing I noticed was increased delicacy in the treble; it goes to show that one man's peakiness is another's music! Regards to all Paul ========================================================================= From: "Paul De Raymond Leclercq" Subject: Re: [JN] 211 vs 845 vs 805 Date: Sat, 7 Jul 2001 09:18:18 -0700 Source: Sound Digest Archive v02.n921 Hello. 866 is a mercury vapour rectifier; this one can give you about 5kV at a quarter of an amp! 811 has its fans - there is a version manufactured by Svetlana. I believe that this type is used in what is known as "Class A2", where some grid current is drawn and a driver transformer is required.. From my point of view the rarity of true audio types is frustrating; many of the rf types are very attractive. As an example I have some 826s; these look superb lit up but judging by what my valve tester tells me, they are strictly class C. Grrrrrr! Best wishes Paul - ----- Original Message ----- From: Richard C Nevill To: Grover Gardner Cc: Sent: Friday, July 06, 2001 7:25 PM Subject: Re: [JN] 211 vs 845 vs 805 > > Okay, > > Being new to this tube stuff I have a pair of RCA 811A's ( Jeremy E. > didn't you want them?), a single GE DR-811 and a couple of 866's, one > globe and the other coke bottle. > > So besides the big B+'s these need are they any good as audio tubes? > Seeing in the subject 800 series tubes I thought I would ask. I believe I > read somewhere that during Desert Storm the SS radios the US was using had > problems with the sand and they dug out all their old tube stuff that used > 811's. After that no problems > > Well, cheers gang > > Richard Nevill > > > > > ========================================================================= From: Grover Gardner Subject: Re: [JN] 211 vs 845 vs 805 Date: Sat, 07 Jul 2001 21:36:56 -0400 Source: Sound Digest Archive v02.n921 Paul De Raymond Leclercq wrote: > > Hello. > > but the 845 only needs -150 volts bias in Class A at > > 1200VDC. Still that's a hefty difference. > > I have just had a look at the data for 845. At 1.2kV and -150V, the valve > would be passing about 135mA, i.e. 162W - more than double its 75W Pa limit. > At 1.2kV you would need bias of about -180V to run 63mA which would give you > 75W Pa. Well, at 950VDC Class A I've never had to bias them at more than -120 for 80mA. That's the Chinese version, anyway. But AB PP would be another matter... > > > > The 845 also has a mu of 8, I believe. > > I was wrong too! It is 5.3 > > > There is an issue of a slightly peaky, edgy sound to the highs that I've > never quite gotten past, sort of what you'd expect from a triode-wired > pentode, if you know what I mean. > -- > > This is very interesting; when I changed from 845s to 813s (at 980V) the > first thing I noticed was increased delicacy in the treble; it goes to show > that one man's peakiness is another's music! Yes, but we're talking PP versus SE here, no? I suspect there are some characteristics that appear in SE that are cancelled or ameliorated in PP. I'm not the only one who has noticed this--Roscoe Primrose also noticed the same thing. However, I think that a little work with the tube in SE could perhaps solve the problem. It's still worth pursuing for the advantages it offers. - -- Grover Gardner groverg@postoffice.att.net Visit my web site at http://home.att.net/~groverg/homepage.htm ========================================================================= From: j45yip@netscape.net (Johari Yip) Subject: Re: [JN] 211 vs 845 vs 805 Date: Sun, 08 Jul 2001 00:49:31 -0400 Source: Sound Digest Archive v02.n921 "Paul De Raymond Leclercq" wrote: > > From my point of view the rarity of true audio types is frustrating; many of > the rf types are very attractive.  As an example I have some 826s; these > look superb lit up but judging by what my valve tester tells me, they are > strictly class C.  Grrrrrr! > > Best wishes > > Paul Hi Paul, At the moment, I'm working on a circuit that appeared in Shishido's transmitter tube book using the 826. The circuit uses a NC10 i/t to drive the 826 into classA2. The driver tube is the 6em7 used in the standard configuration with about 30ma running thru the second ttiode half. I can't get my hands on the NC10 and thought of using the EP 1:1 i/t instead...anybody has idea if this will work in pla ce of the NC10? Yes, the 826 do light up beautifully...8^) - -- Johari Yip =================== j45yip@netscape.net =================== __________________________________________________________________ Get your own FREE, personal Netscape Webmail account today at http://webmail.netscape.com/ ========================================================================= From: "Paul De Raymond Leclercq" Subject: Re: [JN] 211 vs 845 vs 805 Date: Sun, 8 Jul 2001 11:29:11 -0700 Source: Sound Digest Archive v02.n921 Hello Grover, everybody. > Well, at 950VDC Class A I've never had to bias them at more than -120 > for 80mA. That's the Chinese version, anyway. But AB PP would be > another matter... Yes, I ran mine in push-pull (they were the Chinese ones too) but Class A. This was about three years ago and my memory is a bit hazy. Va was 980V and bias about -150 which suggest that I was running 60mA per valve. > > > Yes, but we're talking PP versus SE here, no? I suspect there are some > characteristics that appear in SE that are cancelled or ameliorated in > PP. I'm not the only one who has noticed this--Roscoe Primrose also > noticed the same thing. However, I think that a little work with the > tube in SE could perhaps solve the problem. It's still worth pursuing > for the advantages it offers. Yes, the amplifier is now entirely differential and driven by balanced line from yet more differentials in the line stage (got to find a way to use up some of the valves that are enguilfing my little flat!).. Obviously perfromance and sound will be very different; the books say that even-order harmoniscs will be cancelled and odd-orders doubled. Regards PAul ========================================================================= From: "Paul De Raymond Leclercq" Subject: Re: [JN] 211 vs 845 vs 805 Date: Sun, 8 Jul 2001 11:34:12 -0700 Source: Sound Digest Archive v02.n921 Johari, thanks for that; I shall be interested to hear of your progress. I am afraid that I have no knowledge of interstage transformers, so I cannot help. Regards Paul - ----- Original Message ----- From: Johari Yip To: Cc: Sent: Saturday, July 07, 2001 9:49 PM Subject: Re: [JN] 211 vs 845 vs 805 "Paul De Raymond Leclercq" wrote: > > From my point of view the rarity of true audio types is frustrating; many of > the rf types are very attractive. As an example I have some 826s; these > look superb lit up but judging by what my valve tester tells me, they are > strictly class C. Grrrrrr! > > Best wishes > > Paul Hi Paul, At the moment, I'm working on a circuit that appeared in Shishido's transmitter tube book using the 826. The circuit uses a NC10 i/t to drive the 826 into classA2. The driver tube is the 6em7 used in the standard configuration with about 30ma running thru the second ttiode half. I can't get my hands on the NC10 and thought of using the EP 1:1 i/t instead...anybody has idea if this will work in place of the NC10? Yes, the 826 do light up beautifully...8^) - -- Johari Yip =================== j45yip@netscape.net =================== __________________________________________________________________ Get your own FREE, personal Netscape Webmail account today at http://webmail.netscape.com/ ========================================================================= From: TubeGarden@aol.com Subject: [JN] 211 vs 845 vs 805 Date: Sun, 8 Jul 2001 09:06:37 EDT Source: Sound Digest Archive v02.n922 - --part1_e8.173a91e3.2879b4dd_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 7/8/01 3:33:31 AM US Mountain Standard Time, Pderl@btinternet.com writes: > Yes, the amplifier is now entirely differential and driven by balanced line > from yet more differentials in the line stage (got to find a way to use up > some of the valves that are enguilfing my little flat!).. Obviously > perfromance and sound will be very different; the books say that even-order > harmoniscs will be cancelled and odd-orders doubled. > Greets! Using TubeCAD for SE, I find operating points which have very low distortion. subtext: vary network id=localcdrm active Sorry, my brain just slipped a couple decades, where was... oh, yes, while these 'low points" are not wide band, I am working under the illusion that idle clarity, clarity at idle, supports low level detail :) Someday I will hook up my 334A and measure,,, The fake law pots are terrific, NTE formed carbon linear 2W 25K $6.95 :) Happy Ears! Al B^} - --part1_e8.173a91e3.2879b4dd_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 7/8/01 3:3 3:31 AM US Mountain Standard Time,
Pderl@btinternet.com writes:


Yes, the amplifier is now  entirely differential and driven by balanced li ne
from yet more differentials in the line stage (got to find a way to use up
some of the valves that are enguilfing my little flat!)..  Obviously
perfromance and sound will be very different; the books say that even-order
harmoniscs will be cancelled and odd-orders doubled.


Greets!

Using TubeCAD for SE, I find operating points which have very low distortion.

subtext: vary network id=localcdrm active

Sorry, my brain just slipped a couple decades, where was...

oh, yes, while these 'low points" are not wide band, I am working under the
illusion that idle clarity, clarity at idle, supports low level detail :)

Someday I will hook up my 334A and measure,,,

The fake law pots are terrific, NTE formed carbon linear 2W 25K $6.95 :)

Happy Ears!
Al        B^}

- --part1_e8.173a91e3.2879b4dd_boundary-- ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 211 vs 845 vs 805 Date: Mon, 09 Jul 2001 10:49:53 -0400 Source: Sound Digest Archive v02.n922 i have had suprisingly very good results with SV572-160 (very similar to RCA 811A characteristics) in class A2. running at only 500V or so. bias between +18 to +30V. http://www.geocities.com/bobdanielak/sesv572-160.gif this version uses cathode drive (grounded grid) in the output stage (which is neat when you use IT drive, because you can cancel DC flux if you play your cards right). but it sounds just as good with plain old grid drive. steve bench also published some great work on A2 amps in general, but specifically used the sv572-160, too. the 811A ought to drop right in to that amp, as well. plate caps are cool! bob.d. > ---------- > From: Richard C Nevill[SMTP:rnevill@is.dal.ca] > Sent: Friday, July 06, 2001 10:25 PM > To: Grover Gardner > Cc: sound@io.com > Subject: Re: [JN] 211 vs 845 vs 805 > > > Okay, > > Being new to this tube stuff I have a pair of RCA 811A's ( Jeremy E. > didn't you want them?), a single GE DR-811 and a couple of 866's, one > globe and the other coke bottle. > > So besides the big B+'s these need are they any good as audio tubes? > Seeing in the subject 800 series tubes I thought I would ask. I believe I > read somewhere that during Desert Storm the SS radios the US was using had > problems with the sand and they dug out all their old tube stuff that used > 811's. After that no problems > > Well, cheers gang > > Richard Nevill > > > > > ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 211 vs 845 vs 805 Date: Mon, 09 Jul 2001 11:09:08 -0400 Source: Sound Digest Archive v02.n922 class A2 is not as bad as you might think. if you have a decent driver, it can sound very good. steve bench has done a lot of detailed study on A2 operation: http://members.aol.com/sbench/a2part1.html and he comes up with a driver that doesn't resort to transformers. i've tried both ways, and have been lucky to have a few 10:1 step-down transformers that do the trick. i've also experimented with the 826 (thanks to gary kaufman). this was in a circuit very similar to my SE 833 amp: http://www.geocities.com/bobdanielak/se833nynoise.gif the filament voltage for the 826 is 7.5V, but i was able to run the 826 from 6.3VCT. i used anywhere between +10 and +25V of positive bias, with a B+ supply of 500 to 660V. within their power limits, all of these medium mu (30 to 35) transmitting tubes all performed well. they seem to share a similar sonic signature, too. so the final choice can be left to visual appeal. the 826 is cute, the 812 looks like an 807 or 811A, the eimac 250-th is really cool, too. the 833, though, is the most radical of the lot... there are plenty more to choose from. have a blast... > Hello. > > 866 is a mercury vapour rectifier; this one can give you about 5kV at a > quarter of an amp! > > 811 has its fans - there is a version manufactured by Svetlana. I > believe > that this type is used in what is known as "Class A2", where some grid > current is drawn and a driver transformer is required.. > > From my point of view the rarity of true audio types is frustrating; many > of > the rf types are very attractive. As an example I have some 826s; these > look superb lit up but judging by what my valve tester tells me, they are > strictly class C. Grrrrrr! > > Best wishes > > Paul > ----- Original Message ----- > From: Richard C Nevill > To: Grover Gardner > Cc: > Sent: Friday, July 06, 2001 7:25 PM > Subject: Re: [JN] 211 vs 845 vs 805 > > > > > > Okay, > > > > Being new to this tube stuff I have a pair of RCA 811A's ( Jeremy E. > > didn't you want them?), a single GE DR-811 and a couple of 866's, one > > globe and the other coke bottle. > > > > So besides the big B+'s these need are they any good as audio tubes? > > Seeing in the subject 800 series tubes I thought I would ask. I believe > I > > read somewhere that during Desert Storm the SS radios the US was using > had > > problems with the sand and they dug out all their old tube stuff that > used > > 811's. After that no problems > > > > Well, cheers gang > > > > Richard Nevill > > > > > > > > > > > ========================================================================= From: "Dave Slagle" Subject: Re: [JN] 211 vs 845 vs 805 Date: Mon, 09 Jul 2001 15:02:03 -0400 Source: Sound Digest Archive v02.n922 > At the moment, I'm working on a circuit that appeared in Shishido's > transmitter tube book using the 826. The circuit uses a NC10 i/t to drive > the 826 into classA2. The driver tube is the 6em7 used in the standard > configuration with about 30ma running thru the second ttiode half. I can't > get my hands on the NC10 and thought of using the EP 1:1 i/t > instead...anybody has idea if this will work in place of the NC10? > Yes, the 826 do light up beautifully...8^) i think the NC-10 is one of the units designed for IIT (inverted interstage transformer) usage, so the EP will not replace it. it will work though if you bias the 826 negatively... the ep trannie is bifilar and you cannot reverse polarity of the secondary for iit usage. dave ========================================================================= From: "Snoopy" Subject: Re: [JN] 211 vs 845 vs 805 Date: Tue, 10 Jul 2001 00:32:47 +0800 Source: Sound Digest Archive v02.n922 Dear all, Thanks all for the advice. I will stick to the 211 for the time being, and tweak it to suit my taste. Best Regards, Tung-cheung MA HONG KONG - ----- Original Message ----- From: "Snoopy" To: Sent: Friday, July 06, 2001 12:18 PM Subject: [JN] 211 vs 845 vs 805 > Hi, > > I have the chance of buying a pair of chinese-made 211 se monoblocks. > Each monoblock is using one 6sn7, one 6sl7 and one 211. I am wondering if > it can be easily adapted to use 845 or 805 instead. > > 1. For se design, what's the difference between 211 and 845 in terms of > sound quality, operating points and power output? > > 2. How about the difference between 845 and 805? > > 3. Is there any se or pp schematics using the 805? Is the 805 suitable > for audio? > > I have a pair of G.E. 211 acquired from Edward Billeci long ago. I know > that vintage NOS 845 is expensive, but my friend can offer some United 805 > to me at a reasonable price. Quice interesting to know that the plate of > 805 is at the top of the tube. > > Any advice/information is greatly appreciated. Thank you in advance. > > Best Regards, > > Tung-cheung MA > HONG KONG > 6 July 2001 > ========================================================================= From: SBench@aol.com Subject: Re: [JN] 211 vs 845 vs 805 Date: Tue, 10 Jul 2001 00:49:39 EDT Source: Sound Digest Archive v02.n922 In a message dated 01-07-09 11:14:26 EDT, robert.m.danielak@lmco.com writes: > class A2 is not as bad as you might think. > if you have a decent driver, it can sound very good. > > steve bench has done a lot of detailed study on A2 operation: > > http://members.aol.com/sbench/a2part1.html > > and he comes up with a driver that doesn't resort to transformers. > > i've tried both ways, and have been lucky to have a few 10:1 > step-down transformers that do the trick. > > i've also experimented with the 826 (thanks to gary kaufman). > > this was in a circuit very similar to my SE 833 amp: > > http://www.geocities.com/bobdanielak/se833nynoise.gif > > the filament voltage for the 826 is 7.5V, but i was able to > run the 826 from 6.3VCT. > > i used anywhere between +10 and +25V of positive bias, with a B+ > supply of 500 to 660V. > > within their power limits, all of these medium mu (30 to 35) > transmitting tubes all performed well. > > they seem to share a similar sonic signature, too. > > so the final choice can be left to visual appeal. > Hi Bob and all, Agree 100%. A2 with a good driver sounds N I C E. ALL of the folks at the couple of auditions I had at work preferred the 841 to the 572-160. (driver etc was the same as noted on my web pages on A2.). The key feature enabling the good sound was the direct coupling. Tried cap coupling to the grid of the driver (exactly the same quiescent point, and the driver not drawing grid current) but the sound was VASTLY inferior. Be prepared to hunt for (and find) several "sweet spots" in the biasing voltage. One big difference between the 841 and 572-160 is the microphonics. Tap on the 572-160 and you can hear it (which is probably why it didn't sound quite as good - acoustic feedback - not enough for oscillation but...). Tap on the 841 and nothing. 841 was dead silent: no hiss, no hum, no microphonics from the input 8532s, the driver 6n30pi or the 841s. Excellent imaging, quick, accurate. Did have to change the VR tubes a few times to get a good set of quiet ones, but once burnt in, no further issues. Was gonna try putting in a set of 809s, but didn't have a ready set so never got around to it, particularly since the 841s sound so dern good. By the way, 811s or 811As drop into the circuit just fine as Bob noted. Didn't do exhaustive tests with them, though. In hindsight, that might not be a bad idea, as soon as I get some extra time. Looking at the 826 specs, I'd believe that ought to work well too. Bob, did you happen to try to see if that really nice feature (center tapped filament) was able to buy anything? I'd expect to be able to pick up just an extra smidgen (precise technical term) of clarity when run "parallel". Haven't tried Bob's transformer coupling, but I'd believe that to be an excellent choice too. The high gain of the 572-160 would also slightly relax the drive issues in that mode. Please note that there's a subtle but very important distinction in the kind of A2 being discussed in this thread. The IDLE voltage and most of the operating range is in positive grid region. This is distinctly different than what you're probably going to see with a 211, where the IDLE is near zero or into negative grid region. Best Regards, Steve ========================================================================= From: j45yip@netscape.net (Johari Yip) Subject: Re: [JN] 211 vs 845 vs 805 Date: Tue, 10 Jul 2001 01:30:28 -0400 Source: Sound Digest Archive v02.n922 SBench@aol.com wrote: > > Looking at the 826 specs, I'd believe that ought to work well too. Bob, > did you happen to try to see if that really nice feature (center tapped > filament) was able to buy anything? I'd expect to be able to pick up just > an extra smidgen (precise technical term) of clarity when run "parallel". > Hi Steve, Thoroughly enjoyed your article on the introduction of A2 amplifier. What a good operating point for the 826 in classA2 then? I know most of the time, you need to 'dial-in' the sound, so to speak. Shi shido operates the 826 at vp of 290v, +45v at the grid, i think and pri. imp. of the optx at 1k25 oh ms. i think the 826 is drawing close to 140ma, if i'm not wrong. - -- Johari Yip =================== j45yip@netscape.net =================== __________________________________________________________________ Get your own FREE, personal Netscape Webmail account today at http://webmail.netscape.com/ ========================================================================= From: pderl@btinternet.com Subject: Re: [JN] 211 vs 845 vs 805 Date: Tue, 10 Jul 2001 12:32:59 00100 Source: Sound Digest Archive v02.n922 Hello, I have a few 826s; are there any data for operation in push-pull? Obviously, conventional operation is out because of the high anode resistance. Perhaps operation with positive grids is an option? Rgeards Paul Leclercq >In a message dated 01-07-09 11:14:26 EDT, robert.m.danielak@lmco.com writes: > >> class A2 is not as bad as you might think. >> if you have a decent driver, it can sound very good. >> >> steve bench has done a lot of detailed study on A2 operation: >> >> http://members.aol.com/sbench/a2part1.html >> >> and he comes up with a driver that doesn't resort to transformers. >> >> i've tried both ways, and have been lucky to have a few 10:1 >> step-down transformers that do the trick. >> >> i've also experimented with the 826 (thanks to gary kaufman). >> >> this was in a circuit very similar to my SE 833 amp: >> >> http://www.geocities.com/bobdanielak/se833nynoise.gif >> >> the filament voltage for the 826 is 7.5V, but i was able to >> run the 826 from 6.3VCT. >> >> i used anywhere between +10 and +25V of positive bias, with a B+ >> supply of 500 to 660V. >> >> within their power limits, all of these medium mu (30 to 35) >> transmitting tubes all performed well. >> >> they seem to share a similar sonic signature, too. >> >> so the final choice can be left to visual appeal. >> > >Hi Bob and all, >Agree 100%. A2 with a good driver sounds N I C E. ALL of the >folks at the couple of auditions I had at work preferred the 841 >to the 572-160. (driver etc was the same as noted on my web pages >on A2.). The key feature enabling the good sound was the direct >coupling. Tried cap coupling to the grid of the driver (exactly the >same quiescent point, and the driver not drawing grid current) but the >sound was VASTLY inferior. > >Be prepared to hunt for (and find) several "sweet spots" in the biasing >voltage. > >One big difference between the 841 and 572-160 is the microphonics. >Tap on the 572-160 and you can hear it (which is probably why it didn't >sound quite as good - acoustic feedback - not enough for oscillation but...). >Tap on the 841 and nothing. 841 was dead silent: no hiss, no hum, >no microphonics from the input 8532s, the driver 6n30pi or the 841s. >Excellent imaging, quick, accurate. Did have to change the VR tubes a few >times to get a good set of quiet ones, but once burnt in, no further issues. > >Was gonna try putting in a set of 809s, but didn't have a ready set so never >got around to it, particularly since the 841s sound so dern good. > >By the way, 811s or 811As drop into the circuit just fine as Bob noted. >Didn't do exhaustive tests with them, though. In hindsight, that might >not be a bad idea, as soon as I get some extra time. > >Looking at the 826 specs, I'd believe that ought to work well too. Bob, >did you happen to try to see if that really nice feature (center tapped >filament) was able to buy anything? I'd expect to be able to pick up just >an extra smidgen (precise technical term) of clarity when run "parallel". > >Haven't tried Bob's transformer coupling, but I'd believe that to be >an excellent choice too. The high gain of the 572-160 would also >slightly relax the drive issues in that mode. > >Please note that there's a subtle but very important distinction in the >kind of A2 being discussed in this thread. The IDLE voltage and most >of the operating range is in positive grid region. This is distinctly >different than what you're probably going to see with a 211, where the >IDLE is near zero or into negative grid region. > >Best Regards, >Steve > ========================================================================= From: Roscoe Primrose Subject: Re: [JN] 211 vs 845 vs 805 Date: Tue, 10 Jul 2001 00:10:40 -0400 Source: Sound Digest Archive v02.n923 SBench@aol.com wrote: >> and all other things equal, i have prefered metal plate tubes over >> > graphite, > >> for some reason. >> > > with one exception ---> 813 In my amp, a low-voltage triode wired 813, the metal plate fared better every time. Only one data point though... Peace - -- Roscoe Primrose - -- mailto:roscoe@aiko.com -- http://www.aiko.com/roscoe -- "Once in a while you get shown the light In the strangest of places if you look at it right." Robert Hunter ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 211 vs 845 vs 805 Date: Tue, 10 Jul 2001 19:24:00 -0400 Source: Sound Digest Archive v02.n923 > > > > Hi Bob and all, > Agree 100%. A2 with a good driver sounds N I C E. ALL of the > folks at the couple of auditions I had at work preferred the 841 > to the 572-160. (driver etc was the same as noted on my web pages > on A2.). > in retrospect, i see quite a few differences between these two tubes. correct me if i am wrong, but i thought the 841 is more of a medium mu animal (between 30 and 40). in this case it falls in line with 826, 812, 250-th, and many others. the sv-572 has a mu of around 160, like 811A, 572B, 808 (i think). the sv572-160 also has graphite plate (like 572b). and all other things equal, i have prefered metal plate tubes over graphite, for some reason. i have not retrofit 811A into my 572-160 amp, but i'd bet it would sound better. the 572-160 amp is not too hard to take, though. in fact, it's very nice. > The key feature enabling the good sound was the direct > coupling. Tried cap coupling to the grid of the driver (exactly the > same quiescent point, and the driver not drawing grid current) but the > sound was VASTLY inferior. > not suprised. there's something fundamentally wrong with cap coupling to a A2 grid. the changing impedance causes rectification effects whereby the signal amplitude dynamically adjusts the instantaneous bias. that's got to screw with the sound, right? however, i have heard a cap coupled design (essentially a copy of eric barbour's 1st sv811-10 amp with 6sn7 driver) that was not half bad. for a time i pondered whether this effect could have some GOOD effects. > Be prepared to hunt for (and find) several "sweet spots" in the biasing > voltage. > > this is definitely some new ground to cover: completely ignored properties of filamentary triodes, brought to light, maybe... i certainly noted that in my 572-160 amp, there was a definite sweet spot when adjusting from zero bias up toward +25V. what was intriguing was that it occurred much earlier than i would have thought. in other words, at zero volts, there was practically no bias, the tube was essentially cut-off for a big part of the audio modulation. 5V barely gave me 10 or 20mA of headroom, but the amp played loudly with good sound. for best linearity, my calculations said i needed about 25 to 30V, but the sound seemed to "bloom" at 19V. steve clued me in that these sweet spots may tend to repeat. so i revisited this experiment. above 5V we at least had listenable music, but the 1st bloom seemed to cut in at 16V or so, then again at 19V, then again at 22 or 23, and maybe again before 30V. the definite sweet spot of them all was eithe the 19V or 23V one (don't recall) and nothing like the predicted 28V (or whatever it was). this apparently had nothing to do with bias headroom, linearity of operating point, etc. this was something else... i believe steve says it has more to do with the structure of the filament, itself. brilliant stuff... > One big difference between the 841 and 572-160 is the microphonics. > Tap on the 572-160 and you can hear it (which is probably why it didn't > sound quite as good - acoustic feedback - not enough for oscillation > but...). > Tap on the 841 and nothing. 841 was dead silent: no hiss, no hum, > no microphonics from the input 8532s, the driver 6n30pi or the 841s. > this is very interesting. i recently moved my sv572-160 amp to the "audition shelf" which sits between my speakers. and for some reason, it did not sound as good as i had recalled. (it has beed a few weeks since i last heard it...) i do get some vibration in to this shelf. maybe i need to damp it out.... > Excellent imaging, quick, accurate. Did have to change the VR tubes a few > times to get a good set of quiet ones, but once burnt in, no further > issues. > > Was gonna try putting in a set of 809s, but didn't have a ready set so > never > got around to it, particularly since the 841s sound so dern good. > > By the way, 811s or 811As drop into the circuit just fine as Bob noted. > Didn't do exhaustive tests with them, though. In hindsight, that might > not be a bad idea, as soon as I get some extra time. > i think just about any transmitting triode will drop in. just adjust the bias (by ear!!!). as noted above, the 811A has very high mu, so the gain may be excessive for some tastes. however, i switched to cathode drive and the sensitivity drops significantly. in my case, i think it's just right... another issue with these different tube types: the plate resistance of the 811A/ sv572-160 is pretty high. like 5 to 10K, compared to <5K for 801, 841, 572-30, 812, etc. however, on just about all of these tubes, a 10k load seems to work just fine. i don't seem to have a problem with a damping factor around 1... > Looking at the 826 specs, I'd believe that ought to work well too. Bob, > did you happen to try to see if that really nice feature (center tapped > filament) was able to buy anything? > no, i haven't. but this should be easy enough to try. i have a few small power supplies that wouldn't give me 7.5V at the required current, but should do 3.75V... thanks for the tip... > I'd expect to be able to pick up just > an extra smidgen (precise technical term) of clarity when run "parallel". > have to think about why this would be, but i don't doubt you... > Haven't tried Bob's transformer coupling, but I'd believe that to be > an excellent choice too. The high gain of the 572-160 would also > slightly relax the drive issues in that mode. > yeah. even with a 10:1 step-down, it's no problem... ;) > Please note that there's a subtle but very important distinction in the > kind of A2 being discussed in this thread. The IDLE voltage and most > of the operating range is in positive grid region. This is distinctly > different than what you're probably going to see with a 211, where the > IDLE is near zero or into negative grid region. > i agree. but i may have some conflicting observations... there is fundamentally something different between an amp with significant positive bias and a zero-bias amp. if you use enough positive bias, you might only rarely drive the grid below zero (into A1). for the most-part you stay in one quadrant. in zero bias, you (attempt to) span equally into positive and negative grid swings. you draw grid current only for about 1/2 the cycle. the former seems intuitively better, once you've designed the driver to go into grid current, you may as well stay there. i've experimented with a direct coupled design that used the grid as a load (no additional load resistor, the grid current was the load). this seemed to be quite do-able, if i had the right driver tube for the job (which i didn't). a choke in parallel (essentially a choke load, that didn't take all of the driver dc current) seemed to make it better, though. HOWEVER, as i have found with my 833 amp, zero bias can work and sound just as good as "deep A2" if the driver is stupid-low in impedance (like 10 - 20 ohm). maybe it's not the same, but increasing bias to +5, +10, +15V did not seem to make as much difference as i would have expected. so i am still puzzled, and intrigued. there is still a lot of work to be done in A2. i got laughed at 6 years ago when i started playing with a class A2 211 design. and i've done a lot of A2 amps using sv811-10, sv-572-10/30 812, etc over the years. but it wasn't til a few months ago that i found something that i am SURE sounds world-class. and the shared experiences of my esteemed collegues only helps to encourage me and excite me. thanks to steve, in particular, for spending the time to document your results. i hope more of you will pick up on this. it is a relatively easy way to put garden-variety transmitting tubes to good use. and they look cool too! gotta run, bob.d. ========================================================================= From: SBench@aol.com Subject: Re: [JN] 211 vs 845 vs 805 Date: Tue, 10 Jul 2001 23:33:04 EDT Source: Sound Digest Archive v02.n923 Hi Bob and all, In a message dated 01-07-10 19:25:21 EDT, robert.m.danielak@lmco.com writes: > correct me if i am wrong, but i thought the 841 is more of a medium mu > animal (between 30 and 40). > > in this case it falls in line with 826, 812, 250-th, and many others. Yep! correct. 841 looks just like an 801, except the grid structure is finer pitched. > > the sv-572 has a mu of around 160, like 811A, 572B, 808 (i think). > > the sv572-160 also has graphite plate (like 572b). > and all other things equal, i have prefered metal plate tubes over graphite, > for some reason. with one exception ---> 813 > > i have not retrofit 811A into my 572-160 amp, but i'd bet it would sound > better. > > the 572-160 amp is not too hard to take, though. > in fact, it's very nice. Agreed. I could easily convince myself that what I was hearing as not as well defined - smooth - was in fact an artifact of the microphonics. And perhaps to a very minor point the higher rp. > > > The key feature enabling the good sound was the direct > > coupling. Tried cap coupling to the grid of the driver (exactly the > > same quiescent point, and the driver not drawing grid current) but the > > sound was VASTLY inferior. > > > not suprised. > > there's something fundamentally wrong with cap coupling to a A2 grid. > the changing impedance causes rectification effects whereby the signal > amplitude dynamically adjusts the instantaneous bias. > > that's got to screw with the sound, right? Of course. However, my point was that AC coupling into the driver - that is, the grid of the cathode follower - which never hits grid current caused the sound to deterioriate. And moreso than I could attribute to simply the "quality" of the capacitor. > > i certainly noted that in my 572-160 amp, there was a definite sweet spot > when adjusting from zero bias up toward +25V. > > what was intriguing was that it occurred much earlier than i would have > thought. Er, yeah, I'd have to agree. I noticed it with 841 as well. Still preferred the higher positive bias, but the first "sweet spot" was amazingly low in bias voltage. > > in other words, at zero volts, there was practically no bias, the tube was > essentially cut-off for a big part of the audio modulation. > > 5V barely gave me 10 or 20mA of headroom, but the amp played loudly > with good sound. > > for best linearity, my calculations said i needed about 25 to 30V, > but the sound seemed to "bloom" at 19V. > > steve clued me in that these sweet spots may tend to repeat. > > so i revisited this experiment. > > above 5V we at least had listenable music, but the 1st bloom > seemed to cut in at 16V or so, then again at 19V, then again at 22 or 23, > and maybe again before 30V. > > the definite sweet spot of them all was eithe the 19V or 23V one > (don't recall) and nothing like the predicted 28V (or whatever it was). > > this apparently had nothing to do with bias headroom, linearity of operating > point, etc. this was something else... > Yep. It is definitely NOT bias headroom issue. I *think*, but can not yet prove that it has to do with DHT. See also below. > i recently moved my sv572-160 amp to the "audition shelf" > which sits between my speakers. > > and for some reason, it did not sound as good as i had recalled. > (it has beed a few weeks since i last heard it...) > > i do get some vibration in to this shelf. > > maybe i need to damp it out.... It would be interesting to see if you notice any difference with damping. > as noted above, the 811A has very high mu, so the gain may be > excessive for some tastes. Agree. If anyone is serious about 811 or 572-160 (572B) a lower gain driver circuit would be more optimum. With ear to the speaker cone, you can hear the noise (hiss) from the input 8532s. This was not at all audible with the 841s in place. > > however, i switched to cathode drive and the sensitivity > drops significantly. in my case, i think it's just right... ooohh. Interesting. I would not have guessed that. > > another issue with these different tube types: > > the plate resistance of the 811A/ sv572-160 is pretty high. > like 5 to 10K, compared to <5K for 801, 841, 572-30, 812, etc. > > however, on just about all of these tubes, a 10k load seems to > work just fine. > > i don't seem to have a problem with a damping factor around 1... I was expecting more overhang, perhaps not as much quickness at the higher output Z. Just didn't happen. Possibly thats a function of the speakers and some *need* high damping. Mine don't. Not sure whether to classify that as good or bad :-) > > > Looking at the 826 specs, I'd believe that ought to work well too. Bob, > > did you happen to try to see if that really nice feature (center tapped > > filament) was able to buy anything? > > > no, i haven't. > > but this should be easy enough to try. > > i have a few small power supplies that wouldn't give me 7.5V > at the required current, but should do 3.75V... > > thanks for the tip... > > > I'd expect to be able to pick up just > > an extra smidgen (precise technical term) of clarity when run "parallel". > > > have to think about why this would be, but i don't doubt you... If I'm right, for a constant heating power, as the filament VOLTAGE of directly heated device is lowered (e.g. 1V 10A vs 10V 1A), there becomes less and less of a difference between AC and DC lit filament. Sooo, with that CT and a "real" device [yeah, you *could* test the effect with a "toy" 3V4 or equivalent], you should be able to detect an audible difference between the filament arrangement. [BTW, I'm not knocking 3V4s]. > > > Please note that there's a subtle but very important distinction in the > > kind of A2 being discussed in this thread. The IDLE voltage and most > > of the operating range is in positive grid region. This is distinctly > > different than what you're probably going to see with a 211, where the > > IDLE is near zero or into negative grid region. > > > i agree. but i may have some conflicting observations... > > there is fundamentally something different between an amp with > significant positive bias and a zero-bias amp. > > if you use enough positive bias, you might only rarely drive the grid > below zero (into A1). for the most-part you stay in one quadrant. > > in zero bias, you (attempt to) span equally into positive and negative > grid swings. you draw grid current only for about 1/2 the cycle. > > the former seems intuitively better, once you've designed the driver to go > into grid current, you may as well stay there. > > i've experimented with a direct coupled design that used the grid > as a load (no additional load resistor, the grid current was the load). this > seemed to be quite do-able, if i had the right > driver tube for the job (which i didn't). > > a choke in parallel (essentially a choke load, that didn't take > all of the driver dc current) seemed to make it better, though. > > HOWEVER, as i have found with my 833 amp, zero bias can work > and sound just as good as "deep A2" if the driver is stupid-low > in impedance (like 10 - 20 ohm). Mostly agree. However, if you start straying much above that Z level, then the fun begins. There seems to be NO magic point that is arbitrarily apparent at or near zero bias with even modest dirver circuits. However, until you get near the cathodes saturation point, the gain seems to slightly increase at higher + bias. And that is offset by the greater than zero driver impedance. In the negative bias regime, the "cutoff" starts to lower the output tube mu (at low current and high voltage). But this is precisely where the A1 operation gives you a slightly increased gain in the effective driver circuit. What seems to happen is that it gives you an extension of operation before odd order distortion overtakes even order. Consider a 211, on the other hand. (Which I don't have any of, so can't speak from experience, but *on paper* they look really really good!) You'll need to bias that negatively. So the curvature starts to get you at negative biases and as you go into positive grid region. So, the symmetrical "limiting" starts to add more odd order products. Or so the theory goes. With a very low impedance driver, as you're rightly pointing out, there is probably no penalty either way. > > there is still a lot of work to be done in A2. > Yep! Sure is. > i got laughed at 6 years ago when i started playing with a class A2 211 > design. > > and i've done a lot of A2 amps using sv811-10, sv-572-10/30 > 812, etc over the years. > > but it wasn't til a few months ago that i found something > that i am SURE sounds world-class. > > and the shared experiences of my esteemed collegues only helps to encourage > me and excite me. > > thanks to steve, in particular, for spending the time to document your > results. > > i hope more of you will pick up on this. > > it is a relatively easy way to put garden-variety transmitting tubes to good > use. > > and they look cool too! > > gotta run, > > bob.d. > And I'd like to add to that as well. Before I started re-examining the A2 issue, I was SURE A2 couldn't produce as good sounding amplifier as A1, but I was simply not correct in that assureance. Best Regards, Steve ========================================================================= From: TubeGarden@aol.com Subject: Re: [JN] 211 vs 845 vs 805 Date: Wed, 11 Jul 2001 07:05:48 EDT Source: Sound Digest Archive v02.n923 - --part1_6b.16f78cfc.287d8d0c_boundary Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 7/10/01 8:36:07 PM US Mountain Standard Time, SBench@aol.com writes: > Before I started re-examining the A2 issue, > I was SURE A2 couldn't produce as good sounding amplifier as A1, but > I was simply not correct in that assureance Greets! When I was building "Enhanced Triode Mode" circuits, thank you Tim Pavaricini, where ever you are, using horizontal amplifiers, cheap and plentiful, I was always in A2. Some circuits I used half of B+ for output tube bias. I am not surprised real DH xmit triodes, not as cheap, work well in A2 :) Fickleness on my part caused me to move on. Not sonic quality. Having surveyed many topologies, I am now hanging with the vacuum tube diode bias and transformer coupling. I am going to revisit parafeed with this beast. Now Playing is KT88. Rp is below 900 in triode. The dynamic scale is big thru the ehorns. Big big. 6520 is in the queue, too. Happy Ears! Al B^} - --part1_6b.16f78cfc.287d8d0c_boundary Content-Type: text/html; charset="US-ASCII" Content-Transfer-Encoding: 7bit In a message dated 7/10/01 8: 36:07 PM US Mountain Standard Time,
SBench@aol.com writes:


Before I started re-examining the A2 issue,
I was SURE A2 couldn't produce as good sounding amplifier as A1, but
I was simply not correct in that assureance
Greets!

When I was building "Enhanced Triode Mode" circuits, thank you Tim
Pavaricini, where ever you are, using horizontal amplifiers, cheap and
plentiful, I was always in A2. Some circuits I used half of B+ for output
tube bias. I am not surprised real DH xmit triodes, not as cheap, work well
in A2 :)

Fickleness on my part caused me to move on. Not sonic quality.

Having surveyed many topologies, I am now hanging with the vacuum tube diode
bias and transformer coupling.

I am going to revisit parafeed with this beast.

Now Playing is KT88. Rp is below 900 in triode. The dynamic scale is big thru
the ehorns. Big big.

6520 is in the queue, too.

Happy Ears!
Al      B^}

- --part1_6b.16f78cfc.287d8d0c_boundary-- ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 211 vs 845 vs 805 Date: Mon, 30 Jul 2001 11:42:34 -0400 Source: Sound Digest Archive v02.n936 here is some of that 845/211/826/833 thread for kevin > ---------- > From: Danielak, Robert M > Sent: Tuesday, July 10, 2001 7:24 PM > To: sound@io.com; Danielak, Robert M; 'SBench@aol.com' > Subject: RE: [JN] 211 vs 845 vs 805 > > > > > > > Hi Bob and all, > Agree 100%. A2 with a good driver sounds N I C E. ALL of the > folks at the couple of auditions I had at work preferred the 841 > to the 572-160. (driver etc was the same as noted on my web pages > on A2.). > > in retrospect, i see quite a few differences between these two tubes. > > correct me if i am wrong, but i thought the 841 is more of a medium mu > animal (between 30 and 40). > > in this case it falls in line with 826, 812, 250-th, and many others. > > the sv-572 has a mu of around 160, like 811A, 572B, 808 (i think). > > the sv572-160 also has graphite plate (like 572b). > and all other things equal, i have prefered metal plate tubes over > graphite, for some reason. > > i have not retrofit 811A into my 572-160 amp, but i'd bet it would sound > better. > > the 572-160 amp is not too hard to take, though. > in fact, it's very nice. > > The key feature enabling the good sound was the direct > coupling. Tried cap coupling to the grid of the driver (exactly the > same quiescent point, and the driver not drawing grid current) but > the > sound was VASTLY inferior. > > not suprised. > > there's something fundamentally wrong with cap coupling to a A2 grid. > the changing impedance causes rectification effects whereby the signal > amplitude dynamically adjusts the instantaneous bias. > > that's got to screw with the sound, right? > > however, i have heard a cap coupled design (essentially a copy > of eric barbour's 1st sv811-10 amp with 6sn7 driver) > that was not half bad. > > for a time i pondered whether this effect could have some > GOOD effects. > > > > Be prepared to hunt for (and find) several "sweet spots" in the > biasing > voltage. > > > this is definitely some new ground to cover: > > completely ignored properties of filamentary triodes, brought to light, > maybe... > > i certainly noted that in my 572-160 amp, there was a definite sweet spot > when adjusting from zero bias up toward +25V. > > what was intriguing was that it occurred much earlier than i would have > thought. > > in other words, at zero volts, there was practically no bias, the tube was > essentially cut-off for a big part of the audio modulation. > > 5V barely gave me 10 or 20mA of headroom, but the amp played loudly > with good sound. > > for best linearity, my calculations said i needed about 25 to 30V, > but the sound seemed to "bloom" at 19V. > > steve clued me in that these sweet spots may tend to repeat. > > so i revisited this experiment. > > above 5V we at least had listenable music, but the 1st bloom > seemed to cut in at 16V or so, then again at 19V, then again at 22 or 23, > and maybe again before 30V. > > the definite sweet spot of them all was eithe the 19V or 23V one > (don't recall) and nothing like the predicted 28V (or whatever it was). > > this apparently had nothing to do with bias headroom, linearity of > operating point, etc. this was something else... > > i believe steve says it has more to do with the structure of the filament, > itself. > > brilliant stuff... > > One big difference between the 841 and 572-160 is the microphonics. > Tap on the 572-160 and you can hear it (which is probably why it > didn't > sound quite as good - acoustic feedback - not enough for oscillation > but...). > Tap on the 841 and nothing. 841 was dead silent: no hiss, no > hum, > no microphonics from the input 8532s, the driver 6n30pi or the 841s. > > this is very interesting. > > i recently moved my sv572-160 amp to the "audition shelf" > which sits between my speakers. > > and for some reason, it did not sound as good as i had recalled. > (it has beed a few weeks since i last heard it...) > > i do get some vibration in to this shelf. > > maybe i need to damp it out.... > > Excellent imaging, quick, accurate. Did have to change the VR tubes > a few > times to get a good set of quiet ones, but once burnt in, no further > issues. > > Was gonna try putting in a set of 809s, but didn't have a ready set > so never > got around to it, particularly since the 841s sound so dern good. > > By the way, 811s or 811As drop into the circuit just fine as Bob > noted. > Didn't do exhaustive tests with them, though. In hindsight, that > might > not be a bad idea, as soon as I get some extra time. > > i think just about any transmitting triode will drop in. > > just adjust the bias (by ear!!!). > > as noted above, the 811A has very high mu, so the gain may be > excessive for some tastes. > > however, i switched to cathode drive and the sensitivity > drops significantly. in my case, i think it's just right... > > another issue with these different tube types: > > the plate resistance of the 811A/ sv572-160 is pretty high. > like 5 to 10K, compared to <5K for 801, 841, 572-30, 812, etc. > > however, on just about all of these tubes, a 10k load seems to > work just fine. > > i don't seem to have a problem with a damping factor around 1... > > Looking at the 826 specs, I'd believe that ought to work well too. > Bob, > did you happen to try to see if that really nice feature (center > tapped > filament) was able to buy anything? > > no, i haven't. > > but this should be easy enough to try. > > i have a few small power supplies that wouldn't give me 7.5V > at the required current, but should do 3.75V... > > thanks for the tip... > > I'd expect to be able to pick up just > an extra smidgen (precise technical term) of clarity when run > "parallel". > > have to think about why this would be, but i don't doubt you... > > Haven't tried Bob's transformer coupling, but I'd believe that to be > an excellent choice too. The high gain of the 572-160 would also > slightly relax the drive issues in that mode. > > yeah. even with a 10:1 step-down, it's no problem... ;) > > Please note that there's a subtle but very important distinction in > the > kind of A2 being discussed in this thread. The IDLE voltage and most > of the operating range is in positive grid region. This is > distinctly > different than what you're probably going to see with a 211, where > the > IDLE is near zero or into negative grid region. > > i agree. but i may have some conflicting observations... > > there is fundamentally something different between an amp with > significant positive bias and a zero-bias amp. > > if you use enough positive bias, you might only rarely drive the grid > below zero (into A1). for the most-part you stay in one quadrant. > > in zero bias, you (attempt to) span equally into positive and negative > grid swings. you draw grid current only for about 1/2 the cycle. > > the former seems intuitively better, once you've designed the driver to go > into grid current, you may as well stay there. > > i've experimented with a direct coupled design that used the grid > as a load (no additional load resistor, the grid current was the load). > this seemed to be quite do-able, if i had the right > driver tube for the job (which i didn't). > > a choke in parallel (essentially a choke load, that didn't take > all of the driver dc current) seemed to make it better, though. > > HOWEVER, as i have found with my 833 amp, zero bias can work > and sound just as good as "deep A2" if the driver is stupid-low > in impedance (like 10 - 20 ohm). > > maybe it's not the same, but increasing bias to +5, +10, +15V > did not seem to make as much difference as i would have expected. > > so i am still puzzled, and intrigued. > > there is still a lot of work to be done in A2. > > i got laughed at 6 years ago when i started playing with a class A2 211 > design. > > and i've done a lot of A2 amps using sv811-10, sv-572-10/30 > 812, etc over the years. > > but it wasn't til a few months ago that i found something > that i am SURE sounds world-class. > > and the shared experiences of my esteemed collegues only helps to > encourage me and excite me. > > thanks to steve, in particular, for spending the time to document your > results. > > i hope more of you will pick up on this. > > it is a relatively easy way to put garden-variety transmitting tubes to > good use. > > and they look cool too! > > gotta run, > > bob.d. > > > ========================================================================= From: "Danielak, Robert M" Subject: RE: [JN] 211 vs 845 vs 805 Date: Mon, 30 Jul 2001 11:43:13 -0400 Source: Sound Digest Archive v02.n936 here's more for kevin > ---------- > From: Danielak, Robert M > Sent: Monday, July 09, 2001 11:09 AM > To: sound@io.com > Subject: RE: [JN] 211 vs 845 vs 805 > > class A2 is not as bad as you might think. > if you have a decent driver, it can sound very good. > > steve bench has done a lot of detailed study on A2 operation: > > http://members.aol.com/sbench/a2part1.html > > and he comes up with a driver that doesn't resort to transformers. > > i've tried both ways, and have been lucky to have a few 10:1 > step-down transformers that do the trick. > > i've also experimented with the 826 (thanks to gary kaufman). > > this was in a circuit very similar to my SE 833 amp: > > http://www.geocities.com/bobdanielak/se833nynoise.gif > > the filament voltage for the 826 is 7.5V, but i was able to > run the 826 from 6.3VCT. > > i used anywhere between +10 and +25V of positive bias, with a B+ > supply of 500 to 660V. > > within their power limits, all of these medium mu (30 to 35) > transmitting tubes all performed well. > > they seem to share a similar sonic signature, too. > > so the final choice can be left to visual appeal. > > the 826 is cute, the 812 looks like an 807 or 811A, > the eimac 250-th is really cool, too. > > the 833, though, is the most radical of the lot... > > there are plenty more to choose from. > > have a blast... > > Hello. > > 866 is a mercury vapour rectifier; this one can give you about 5kV > at a > quarter of an amp! > > 811 has its fans - there is a version manufactured by Svetlana. I > believe > that this type is used in what is known as "Class A2", where some > grid > current is drawn and a driver transformer is required.. > > From my point of view the rarity of true audio types is frustrating; > many of > the rf types are very attractive. As an example I have some 826s; > these > look superb lit up but judging by what my valve tester tells me, > they are > strictly class C. Grrrrrr! > > Best wishes > > Paul > ----- Original Message ----- > From: Richard C Nevill > To: Grover Gardner > Cc: > Sent: Friday, July 06, 2001 7:25 PM > Subject: Re: [JN] 211 vs 845 vs 805 > > > > > > Okay, > > > > Being new to this tube stuff I have a pair of RCA 811A's ( > Jeremy E. > > didn't you want them?), a single GE DR-811 and a couple of 866's, > one > > globe and the other coke bottle. > > > > So besides the big B+'s these need are they any good as audio > tubes? > > Seeing in the subject 800 series tubes I thought I would ask. I > believe I > > read somewhere that during Desert Storm the SS radios the US was > using had > > problems with the sand and they dug out all their old tube stuff > that used > > 811's. After that no problems > > > > Well, cheers gang > > > > Richard Nevill > > > > > > > > > > > > ========================================================================= From: pderl@btinternet.com Subject: RE: [JN] 211 vs 845 vs 805 Date: Mon, 30 Jul 2001 17:35:32 +0100 (BST) Source: Sound Digest Archive v02.n936 Well if you want BIG I have it! Have a look at this: http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1621486566&r=0&t=0&showTutorial=0&ed=99694520 7&indexURL=0&rd=1 Email me if you would like a picture Paul > > here is some of that 845/211/826/833 thread for kevin > > ---------- > > From: Danielak, Robert M > > Sent: Tuesday, July 10, 2001 7:24 PM > > To: sound@io.com; Danielak, Robert M; 'SBench@aol.com' > > Subject: RE: [JN] 211 vs 845 vs 805 > > > > > > > > > > > > > Hi Bob and all, > > Agree 100%. A2 with a good driver sounds N I C E. ALL of the > > folks at the couple of auditions I had at work preferred the 841 > > to the 572-160. (driver etc was the same as noted on my web pages > > on A2.). > > > > in retrospect, i see quite a few differences between these two tubes. > > > > correct me if i am wrong, but i thought the 841 is more of a medium mu > > animal (between 30 and 40). > > > > in this case it falls in line with 826, 812, 250-th, and many others. > > > > the sv-572 has a mu of around 160, like 811A, 572B, 808 (i think). > > > > the sv572-160 also has graphite plate (like 572b). > > and all other things equal, i have prefered metal plate tubes over > > graphite, for some reason. > > > > i have not retrofit 811A into my 572-160 amp, but i'd bet it would sound > > better. > > > > the 572-160 amp is not too hard to take, though. > > in fact, it's very nice. > > > > The key feature enabling the good sound was the direct > > coupling. Tried cap coupling to the grid of the driver (exactly the > > same quiescent point, and the driver not drawing grid current) but > > the > > sound was VASTLY inferior. > > > > not suprised. > > > > there's something fundamentally wrong with cap coupling to a A2 grid. > > the changing impedance causes rectification effects whereby the signal > > amplitude dynamically adjusts the instantaneous bias. > > > > that's got to screw with the sound, right? > > > > however, i have heard a cap coupled design (essentially a copy > > of eric barbour's 1st sv811-10 amp with 6sn7 driver) > > that was not half bad. > > > > for a time i pondered whether this effect could have some > > GOOD effects. > > > > > > > > Be prepared to hunt for (and find) several "sweet spots" in the > > biasing > > voltage. > > > > > > this is definitely some new ground to cover: > > > > completely ignored properties of filamentary triodes, brought to light, > > maybe... > > > > i certainly noted that in my 572-160 amp, there was a definite sweet spot > > when adjusting from zero bias up toward +25V. > > > > what was intriguing was that it occurred much earlier than i would have > > thought. > > > > in other words, at zero volts, there was practically no bias, the tube was > > essentially cut-off for a big part of the audio modulation. > > > > 5V barely gave me 10 or 20mA of headroom, but the amp played loudly > > with good sound. > > > > for best linearity, my calculations said i needed about 25 to 30V, > > but the sound seemed to "bloom" at 19V. > > > > steve clued me in that these sweet spots may tend to repeat. > > > > so i revisited this experiment. > > > > above 5V we at least had listenable music, but the 1st bloom > > seemed to cut in at 16V or so, then again at 19V, then again at 22 or 23, > > and maybe again before 30V. > > > > the definite sweet spot of them all was eithe the 19V or 23V one > > (don't recall) and nothing like the predicted 28V (or whatever it was). > > > > this apparently had nothing to do with bias headroom, linearity of > > operating point, etc. this was something else... > > > > i believe steve says it has more to do with the structure of the filament, > > itself. > > > > brilliant stuff... > > > > One big difference between the 841 and 572-160 is the microphonics. > > Tap on the 572-160 and you can hear it (which is probably why it > > didn't > > sound quite as good - acoustic feedback - not enough for oscillation > > but...). > > Tap on the 841 and nothing. 841 was dead silent: no hiss, no > > hum, > > no microphonics from the input 8532s, the driver 6n30pi or the 841s. > > > > this is very interesting. > > > > i recently moved my sv572-160 amp to the "audition shelf" > > which sits between my speakers. > > > > and for some reason, it did not sound as good as i had recalled. > > (it has beed a few weeks since i last heard it...) > > > > i do get some vibration in to this shelf. > > > > maybe i need to damp it out.... > > > > Excellent imaging, quick, accurate. Did have to change the VR tubes > > a few > > times to get a good set of quiet ones, but once burnt in, no further > > issues. > > > > Was gonna try putting in a set of 809s, but didn't have a ready set > > so never > > got around to it, particularly since the 841s sound so dern good. > > > > By the way, 811s or 811As drop into the circuit just fine as Bob > > noted. > > Didn't do exhaustive tests with them, though. In hindsight, that > > might > > not be a bad idea, as soon as I get some extra time. > > > > i think just about any transmitting triode will drop in. > > > > just adjust the bias (by ear!!!). > > > > as noted above, the 811A has very high mu, so the gain may be > > excessive for some tastes. > > > > however, i switched to cathode drive and the sensitivity > > drops significantly. in my case, i think it's just right... > > > > another issue with these different tube types: > > > > the plate resistance of the 811A/ sv572-160 is pretty high. > > like 5 to 10K, compared to <5K for 801, 841, 572-30, 812, etc. > > > > however, on just about all of these tubes, a 10k load seems to > > work just fine. > > > > i don't seem to have a problem with a damping factor around 1... > > > > Looking at the 826 specs, I'd believe that ought to work well too. > > Bob, > > did you happen to try to see if that really nice feature (center > > tapped > > filament) was able to buy anything? > > > > no, i haven't. > > > > but this should be easy enough to try. > > > > i have a few small power supplies that wouldn't give me 7.5V > > at the required current, but should do 3.75V... > > > > thanks for the tip... > > > > I'd expect to be able to pick up just > > an extra smidgen (precise technical term) of clarity when run > > "parallel". > > > > have to think about why this would be, but i don't doubt you... > > > > Haven't tried Bob's transformer coupling, but I'd believe that to be > > an excellent choice too. The high gain of the 572-160 would also > > slightly relax the drive issues in that mode. > > > > yeah. even with a 10:1 step-down, it's no problem... ;) > > > > Please note that there's a subtle but very important distinction in > > the > > kind of A2 being discussed in this thread. The IDLE voltage and most > > of the operating range is in positive grid region. This is > > distinctly > > different than what you're probably going to see with a 211, where > > the > > IDLE is near zero or into negative grid region. > > > > i agree. but i may have some conflicting observations... > > > > there is fundamentally something different between an amp with > > significant positive bias and a zero-bias amp. > > > > if you use enough positive bias, you might only rarely drive the grid > > below zero (into A1). for the most-part you stay in one quadrant. > > > > in zero bias, you (attempt to) span equally into positive and negative > > grid swings. you draw grid current only for about 1/2 the cycle. > > > > the former seems intuitively better, once you've designed the driver to go > > into grid current, you may as well stay there. > > > > i've experimented with a direct coupled design that used the grid > > as a load (no additional load resistor, the grid current was the load). > > this seemed to be quite do-able, if i had the right > > driver tube for the job (which i didn't). > > > > a choke in parallel (essentially a choke load, that didn't take > > all of the driver dc current) seemed to make it better, though. > > > > HOWEVER, as i have found with my 833 amp, zero bias can work > > and sound just as good as "deep A2" if the driver is stupid-low > > in impedance (like 10 - 20 ohm). > > > > maybe it's not the same, but increasing bias to +5, +10, +15V > > did not seem to make as much difference as i would have expected. > > > > so i am still puzzled, and intrigued. > > > > there is still a lot of work to be done in A2. > > > > i got laughed at 6 years ago when i started playing with a class A2 211 > > design. > > > > and i've done a lot of A2 amps using sv811-10, sv-572-10/30 > > 812, etc over the years. > > > > but it wasn't til a few months ago that i found something > > that i am SURE sounds world-class. > > > > and the shared experiences of my esteemed collegues only helps to > > encourage me and excite me. > > > > thanks to steve, in particular, for spending the time to document your > > results. > > > > i hope more of you will pick up on this. > > > > it is a relatively easy way to put garden-variety transmitting tubes to > > good use. > > > > and they look cool too! > > > > gotta run, > > > > bob.d. > > > > > > ========================================================================= From: Steve Van Osdell Subject: [JN] 247A WE tubes Date: Sat, 12 Aug 2000 12:55:54 -0400 Source: Sound Digest Archive v02.n625 I've also got a pair of 247A tubes up on ebay (I think they are equal to one side of a 12AX7). If anybody wants them, I can stop the auction because reserve isn't met yet. Are they worth $130 for the pair? NOS in box. Thanks, Steve ========================================================================= From: "BobC" Subject: Re: [JN] 247A WE tubes Date: Sat, 12 Aug 2000 13:38:57 -0400 Source: Sound Digest Archive v02.n625 > If anybody wants them, I can stop the auction > because reserve isn't met yet. Are they worth $130 for the pair? NOS > in box. I believe the reserve isn't met yet because nobody has bid on them. BC ========================================================================= From: tube@jump.net Subject: Re: [JN] 247A WE tubes Date: Sat, 12 Aug 2000 15:44:27 -0500 Source: Sound Digest Archive v02.n625 "Paul@13E1.com" wrote: > Perhaps what Bob meant to say is that they are not worth $130. > > A whole 12AX7 certainly is not, so I doubt that half of one could be!! Actually, I think he was referring to the extremely unlikely possibility of a reserve being met WITHOUT any bidding! I got a good laugh out of it, whatever he was doing ... Phil > > > > > If anybody wants them, I can stop the auction > > > because reserve isn't met yet. Are they worth $130 for the pair? NOS > > > in box. > > > > I believe the reserve isn't met yet because nobody has bid on them. > > > > BC > > > > ========================================================================= From: Steve Van Osdell Subject: Re: [JN] 247A WE tubes Date: Sat, 12 Aug 2000 18:22:18 -0400 Source: Sound Digest Archive v02.n625 Well, first, I was only going by what another person (who should know) told me. And I have seen whole NOS Telefunken 12AX7's going for $60 or more. So, I'm open to more expert opinion about their value (hopefully without sarcasm). Thanks, Steve "Paul@13E1.com" wrote: > Perhaps what Bob meant to say is that they are not worth $130. > > A whole 12AX7 certainly is not, so I doubt that half of one could be!! > > Paul Leclercq [function before fashion :-)] > ----- Original Message ----- > From: BobC > To: Joe List > Sent: Saturday, August 12, 2000 6:38 PM > Subject: Re: [JN] 247A WE tubes > > > > > > > > If anybody wants them, I can stop the auction > > > because reserve isn't met yet. Are they worth $130 for the pair? NOS > > > in box. > > > > I believe the reserve isn't met yet because nobody has bid on them. > > > > BC > > > > ========================================================================= From: Steve Van Osdell Subject: Re: [JN] 247A WE tubes Date: Sat, 12 Aug 2000 18:25:37 -0400 Source: Sound Digest Archive v02.n625 Bob, I think the accuracy of the statement 'reserve isn't met' holds true whether someone has bid or not, or am I mistaken? Are you always this good with stating oxymorons? Steve BobC wrote: > > If anybody wants them, I can stop the auction > > because reserve isn't met yet. Are they worth $130 for the pair? NOS > > in box. > > I believe the reserve isn't met yet because nobody has bid on them. > > BC ========================================================================= From: "Paul@13E1.com" Subject: Re: [JN] 247A WE tubes Date: Sat, 12 Aug 2000 20:53:43 +0100 Source: Sound Digest Archive v02.n625 Perhaps what Bob meant to say is that they are not worth $130. A whole 12AX7 certainly is not, so I doubt that half of one could be!! Paul Leclercq [function before fashion :-)] - ----- Original Message ----- From: BobC To: Joe List Sent: Saturday, August 12, 2000 6:38 PM Subject: Re: [JN] 247A WE tubes > > > > If anybody wants them, I can stop the auction > > because reserve isn't met yet. Are they worth $130 for the pair? NOS > > in box. > > I believe the reserve isn't met yet because nobody has bid on them. > > BC > > ========================================================================= From: "Fred Volz" Subject: Re: [JN] 247A WE tubes Date: Mon, 14 Aug 2000 09:12:47 -0400 Source: Sound Digest Archive v02.n627 - -----Original Message----- From: David Crittle To: sound@lists.io.com Date: Monday, August 14, 2000 8:16 AM Subject: Re: [JN] 247A WE tubes >half a 12AX7? Isn't that a 6AV6? > >David > > According to my tube book, a 6AV6 is a dual diode/triode. If I look up 12AX7, it says to reference 6AV6s triode section for the curves and characteristics. But, the 6AV6 has a max plate dissipation rating of 0.55 Watts while the 12AX7 has a 1.2 Watt rating per section. So, it seems that, while the curves and characteristics are similar, they are not really the same triode. It would be interesting, however, to listen to each of these in a circuit suitably designed to use either tube. 6AV6s cost only half as much as 12AX7s on a per triode basis. Fred Volz fcv@emotiveaudio.com ========================================================================= From: David Crittle Subject: Re: [JN] 247A WE tubes Date: Mon, 14 Aug 2000 21:33:27 +1000 Source: Sound Digest Archive v02.n627 >Well, first, I was only going by what another person (who should know) told >me. And I have seen whole NOS Telefunken 12AX7's going for $60 or more. So, >I'm open to more expert opinion about their value (hopefully without sarcasm). half a 12AX7? Isn't that a 6AV6? David ========================================================================= From: Simon Busbridge Subject: Re: [JN] RE: 24V rms AC is 68V peak-peak, right? Date: Thu, 12 Apr 2001 08:11:07 +0100 (BST) Source: Sound Digest Archive v02.n865 Only if the currents taken from the + and the - supplies are balanced. Otherwise the 'false earth' will waft up or down to one or other of the supplies. You will be relying of charge balancing between the two capacitors to maintain your earth point. Better to use a centre tap. Simon Simon Busbridge, BSc(Hons) PhD CPhys MInstP School of Engineering University of Brighton Lewes Road Moulsecoomb Brighton BN2 4GJ UNITED KINGDOM Tel: 0044 (0)1273 642542 Fax: 0044 (0)1273 642327/642301 e-mail: s.c.busbridge@bton.ac.uk, scbusbridge@hotmail.com On Thu, 12 Apr 2001, Sellek, Grant (TSA) wrote: > Thanks to all those who replied, I certainly gave up the idea > of getting +- 33V rails from a single 24V rms secondary. > I need a 48V rms centre tapped supply, or a pair of 24V rms. > > Now I have to hand a TX with a 46V rms secondary, which is near > enough to the 48V rms I desire, especially as the mains supply > is consistently a bit high at my house. But it has no centre > tap. Is this an impediment? > > I can see no reason against hooking up the 46V secondary, full > bridge the output to get approx 64V DC, floating. Span this > with a pair of series capacitances, and anchor the midpoint to > earth. This will give me near to +32V and -32V rails, with the > centre point earthed. So there seems top be no problem with a > floating secondary winding -- correct? > > Grant > > Grant Sellek, Adelaide, Australia > ========================================================================= From: "Sellek, Grant (TSA)" Subject: [JN] RE: 24V rms AC is 68V peak-peak, right? Date: Thu, 12 Apr 2001 16:20:20 +0930 Source: Sound Digest Archive v02.n865 Thanks to all those who replied, I certainly gave up the idea of getting +- 33V rails from a single 24V rms secondary. I need a 48V rms centre tapped supply, or a pair of 24V rms. Now I have to hand a TX with a 46V rms secondary, which is near enough to the 48V rms I desire, especially as the mains supply is consistently a bit high at my house. But it has no centre tap. Is this an impediment? I can see no reason against hooking up the 46V secondary, full bridge the output to get approx 64V DC, floating. Span this with a pair of series capacitances, and anchor the midpoint to earth. This will give me near to +32V and -32V rails, with the centre point earthed. So there seems top be no problem with a floating secondary winding -- correct? Grant Grant Sellek, Adelaide, Australia ========================================================================= From: alan cameron Subject: [JN] 25W pots for Oz-Joes Date: Wed, 3 Nov 1999 18:34:43 +1000 Source: Sound Digest Archive v02.n320 hi Oz-Joes, the other day I came across a few 5k 25W wire-wound pots, NIB. Just the thing for the cathode resistor of your 2A3 direct coupled amp. If an OzJoe wasnts a couple, let me know and I'll go and get them (if they're still there). Dunno, how does something like ten bucks each sound. My email is very dodgy at he moment; phone on 0408 441 277 might work best. alan still lurking ========================================================================= From: =?iso-8859-1?q?Josef=20Aigner?= Subject: Re: [JN] 26/45 amp. Schematic? Date: Fri, 14 Jan 2000 15:01:11 -0800 (PST) Source: Sound Digest Archive v02.n404 Don, on monday, I have to scan the drawing since I have no software to do this (does somebody know a kind of shareware etc. ?). Josef __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com ========================================================================= From: =?iso-8859-1?q?Josef=20Aigner?= Subject: Re: [JN] 26/45 amp. was: Choke connection Date: Fri, 14 Jan 2000 06:33:36 -0800 (PST) Source: Sound Digest Archive v02.n402 Hi Don, mine is also for a edgarhorn D54/Fostex 925 setup.... josef __________________________________________________ Do You Yahoo!? Talk to your friends online with Yahoo! Messenger. http://im.yahoo.com ========================================================================= From: "Carter Hendricks" Subject: [JN] 26-46 amp Date: Sun, 22 Oct 2000 22:40:11 -0500 Source: Sound Digest Archive v02.n704 I'm admittedly behind on my reports on class [list] projects. I'll wait a while longer before talking about the 46 PP amp. I plan to try a different driver. But I finished another amp, and this one makes me happy. The amp is a 26, direct coupled to a 46. The idea is from Shishido, who used it several times as a driver for his serious A2 amps. I've built with 26 and with 46 and they are wonderful tubes. First: this is a 1.25 watt amp. It will not play symphonic music or heavy metal. It won't play loud. But, as JL says, it's 1,250 mW. It will play small group jazz and classical. It plays too loud to talk. The 46 is run at the standard operating point, 250 volts plate, 33 vgk, 22 mA. To make the direct coupling work, the 46 cathode is elevated to ~ 125 v. [Raw supply is raised to ~345 volts]. The cathode resistance is two 3k Mills in series, each resistor bypassed by a 100uF 100v Muse cap. There is a 56k dropping resistor to a 33k Mills plate resistor for the 26, and I used a fat 2.5k CC cathode resistor bypassed by a pair of 50uF green Muse caps in parallel. The 26 doesn't have enough voltage gain to drive the 46 to full glory. I always use a line stage [right now my 42] but sometimes borrow a CD player or phono stage. So I picked up some extra gain with an A18 step up as an input transformer. [Shishido also used input trannies]. I used a 100k AB pot as a load and volume control. The OPT is the Black Art 417A transformer. It is set up for just 20 mA. It would be fun to try running the 46 like a 45, but not with these OPT's. I prefer 26's at a lower voltage / higher current, but input headroom looked tight. The 26 [and 46] are direct heated. The 26 sounds best humming along on AC [you can get used to it] but sounds almost as good on current regulation. I used a 6.3 x2 mil spec filament transformer, schottkeys, ferrite beads, and a cap and LT1085 to make a raw DC supply to feed the current regulator, which I mounted [with isolation washers & gasket] next to each 26. I used [.5 & .7] 5 watt Mills for the series current set resistors. The 46 just uses an AB 50 ohm balance pot, which I'll parallel with a couple 25 ohm CC's. The power supply uses a MQ transformer and filter choke in an LC. I use a "Gordon" ~.7 film cap before the choke, to adjust the voltage and knock down the uglies. I use beads on the input of the first, 56uF switch grade filter cap. I use more beads and a small amount of resistance before more filter caps [~150uF] and another small R before another 56uF close to the OPT. A small amount of noise can be heard with my ear at each speaker, but I usually don't listen that way. Anna helped me set the hum pots! Amp design is a balance of compromises. On this amp [with a 14 inch square chassis] I wanted to try a quick, fast power supply structure. Shishido was quoted somewhere that he wasn't interested in old tube sound, he wanted modern sound. I think his circuit and this power supply accomplish a clear musical sound. I've been listening to the amp through a borrowed phono stage and a borrowed Exposure CD player. Both sound better driven through the choke-loaded 42 line stage. I'm using my Diatones in 2 cu ft boxes. The amp is fast and lively. I've been listening to some small group Benny Carter jazz while writing this. The strength of the amp is in the clarity of the sax, in pitch, dynamics, and metal tone. BC plays loud, plays soft, and it is all coming through. I keep stopping my writing to listen to Benny Carter. The strengths of a small amp cut both ways. There is great clarity and focus, not in the Charlie Bergan way but in the sense of concentration, of a direct coupling to the music. But this clarity means that each selection in material, layout and circuit is irrevocably part of the design, is part of the music. I know what a cheap [Hammond] filter choke would do to this amp and the music, and I think that part of the clarity of the amp comes from the quality of all of the iron, including the power transformer as well as the OPT's. Ironically, I can't point to the bass or the treble or whatever and say "listen to those Black Art transformers." Instead, the music just seems unimpeded by the amp. [I used these same Black Art transformers with the 417A tube. That amp was transparent, even ruthless, but never made music]. The strength and tone "down there" is better with my 46 PP amp. That one has real control of double bass tone... After writing that last paragraph I put more clothes in the washer and put on a more modern recording, Kenny Barron and Charlie Haden. The bass isn't bad [the 46PP is better] but the piano is wonderfully complex, sweet, thoughtful all the way up and down the keyboard. Next project is to finish my separate phono stage, then start on a similar circuit * to drive 2A3's and MQ OPT's. I don't know what I'll do with all that power. Maybe I'll play some Ellington band music! --Carter * 27 + 42, but both MQ choke loaded, to 2A3. ========================================================================= From: "Carter Hendricks" Subject: Re: [JN] 26-46 amp Date: Sun, 22 Oct 2000 23:43:34 -0500 Source: Sound Digest Archive v02.n704 - ----- Original Message ----- From: John To: Carter Hendricks Sent: 22 October, 2000 10:49 PM Subject: Re: [JN] 26-46 amp > I was browsing around today and saw >Jim de Kort's 26 preamp. He said using > batteries cured his hum problem. It's > something that I'd lik