Sound Practices Mailing List Files - Volume 2
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From: Dan Marshall <mdaniel7@uswest.net>
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
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From: =?iso-8859-1?Q?Tom_Andr=E9_Hansen?= <fishfish@yifan.net>
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
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From: TubeGarden@aol.com
Subject: Re: [JN] 205 ...
Date: Sun, 11 Mar 2001 12:45:31 EST
Source: Sound Digest Archive v02.n830
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Content-Transfer-Encoding: 7bit
dunno
316A is a fine sounding tennis ball, and cheap, to boot :)
Ears!
Al B^}
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<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>dunno
<BR>
<BR>316A is a fine sounding tennis ball, and cheap, to boot :)
<BR>
<BR>Ears!
<BR>
<BR>Al B^}
<BR>
<BR></FONT></HTML>
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From: =?iso-8859-1?Q?Tom_Andr=E9_Hansen?= <fishfish@yifan.net>
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 <adnana@turk.net>
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 <adnana@turk.net>
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 <adnana@turk.net>
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 <adnana@turk.net>
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^}
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From: "Sellek, Grant (TSA)" <Grant.Sellek@transport.sa.gov.au>
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 <philipv@camtech.net.au> 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 <!spam-scottf@bigpond.net.au> 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 <dunker@invalid.ed.ntnu.no>
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 Århus 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." <lecleach@cgi.ensmp.fr>
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 <dunker@invalid.ed.ntnu.no>
> A : Sellek, Grant (TSA) <Grant.Sellek@transport.sa.gov.au>
> Cc : 'Sound Practices' <sound@lists.io.com>
> 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 Århus 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" <TRS@carlsmith.com>
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 <bmann@nexgo.de> 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 <bmann@nexgo.de>
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 <jroberts@io.com>
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" <Pderl@btinternet.com>
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 <tcma@netvigator.com>
To: <sound@io.com>
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" <tcma@netvigator.com>
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)" <Grant.Sellek@transport.sa.gov.au>
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 <groverg@postoffice.att.net>
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 <rnevill@is.dal.ca>
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" <Pderl@btinternet.com>
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" <Pderl@btinternet.com>
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 <rnevill@is.dal.ca>
To: Grover Gardner <groverg@postoffice.att.net>
Cc: <sound@io.com>
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 <groverg@postoffice.att.net>
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" <Pderl@btinternet.com> 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" <Pderl@btinternet.com>
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" <Pderl@btinternet.com>
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 <j45yip@netscape.net>
To: <pderl@btinternet.com>
Cc: <sound@io.com>
Sent: Saturday, July 07, 2001 9:49 PM
Subject: Re: [JN] 211 vs 845 vs 805
"Paul De Raymond Leclercq" <Pderl@btinternet.com> 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
<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>In a message dated 7/8/01 3:3
3:31 AM US Mountain Standard Time,
<BR>Pderl@btinternet.com writes:
<BR>
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px
; PADDING-LEFT: 5px">Yes, the amplifier is now entirely differential and driven by balanced li
ne
<BR>from yet more differentials in the line stage (got to find a way to use up
<BR>some of the valves that are enguilfing my little flat!).. Obviously
<BR>perfromance and sound will be very different; the books say that even-order
<BR>harmoniscs will be cancelled and odd-orders doubled.
<BR></BLOCKQUOTE></FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR>
<BR>Greets!
<BR>
<BR>Using TubeCAD for SE, I find operating points which have very low distortion.
<BR>
<BR>subtext: vary network id=localcdrm active
<BR>
<BR>Sorry, my brain just slipped a couple decades, where was...
<BR>
<BR>oh, yes, while these 'low points" are not wide band, I am working under the
<BR>illusion that idle clarity, clarity at idle, supports low level detail :)
<BR>
<BR>Someday I will hook up my 334A and measure,,,
<BR>
<BR>The fake law pots are terrific, NTE formed carbon linear 2W 25K $6.95 :)
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR>
<BR></FONT></HTML>
- --part1_e8.173a91e3.2879b4dd_boundary--
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
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" <robert.m.danielak@lmco.com>
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 <rnevill@is.dal.ca>
> To: Grover Gardner <groverg@postoffice.att.net>
> Cc: <sound@io.com>
> 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" <dslagle@earthlink.net>
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" <tcma@netvigator.com>
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" <tcma@netvigator.com>
To: <sound@io.com>
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 <roscoe@aiko.com>
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" <robert.m.danielak@lmco.com>
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
<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>In a message dated 7/10/01 8:
36:07 PM US Mountain Standard Time,
<BR>SBench@aol.com writes:
<BR>
<BR>
<BR><BLOCKQUOTE TYPE=CITE style="BORDER-LEFT: #0000ff 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: 0px
; PADDING-LEFT: 5px">Before I started re-examining the A2 issue,
<BR>I was SURE A2 couldn't produce as good sounding amplifier as A1, but
<BR>I was simply not correct in that assureance</FONT><FONT COLOR="#000000" SIZE=3 FAMILY="SANSSERI
F" FACE="Arial" LANG="0"></BLOCKQUOTE>
<BR></FONT><FONT COLOR="#000000" SIZE=2 FAMILY="SANSSERIF" FACE="Arial" LANG="0">
<BR>Greets!
<BR>
<BR>When I was building "Enhanced Triode Mode" circuits, thank you Tim
<BR>Pavaricini, where ever you are, using horizontal amplifiers, cheap and
<BR>plentiful, I was always in A2. Some circuits I used half of B+ for output
<BR>tube bias. I am not surprised real DH xmit triodes, not as cheap, work well
<BR>in A2 :)
<BR>
<BR>Fickleness on my part caused me to move on. Not sonic quality.
<BR>
<BR>Having surveyed many topologies, I am now hanging with the vacuum tube diode
<BR>bias and transformer coupling.
<BR>
<BR>I am going to revisit parafeed with this beast.
<BR>
<BR>Now Playing is KT88. Rp is below 900 in triode. The dynamic scale is big thru
<BR>the ehorns. Big big.
<BR>
<BR>6520 is in the queue, too.
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR>
<BR></FONT></HTML>
- --part1_6b.16f78cfc.287d8d0c_boundary--
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
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" <robert.m.danielak@lmco.com>
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 <rnevill@is.dal.ca>
> To: Grover Gardner <groverg@postoffice.att.net>
> Cc: <sound@io.com>
> 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 <svanos@queencity.com>
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" <bobcx@bellatlantic.net>
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 <svanos@queencity.com>
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 <bobcx@bellatlantic.net>
> To: Joe List <sound@lists.io.com>
> 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 <svanos@queencity.com>
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" <triode@bow-tie.org.uk>
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 <bobcx@bellatlantic.net>
To: Joe List <sound@lists.io.com>
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" <fcv@emotiveaudio.com>
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 <retrovox@bigpond.com>
To: sound@lists.io.com <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 <retrovox@bigpond.com>
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 <S.C.Busbridge@bton.ac.uk>
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)" <Grant.Sellek@transport.sa.gov.au>
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 <alan@thehub.com.au>
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?= <josef_aigner@yahoo.com>
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?= <josef_aigner@yahoo.com>
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" <carter@i1.net>
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" <carter@i1.net>
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 <str8aro@purdue.edu>
To: Carter Hendricks <carter@i1.net>
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 like to try eventually...
I tried batteries and while they "work"
the magic of the 26 just disappears.
I've built 26 and 46 line stages and the
46 has stronger tone. The 42 is powerful
and easier to implement.
--Carter
=========================================================================
From: "Remco Stoutjesdijk" <r.m.stoutjesdijk@student.utwente.nl>
Subject: RE: [JN] 26-46 amp
Date: Mon, 23 Oct 2000 18:15:40 +0200
Source: Sound Digest Archive v02.n705
> I tried batteries and while they "work"
> the magic of the 26 just disappears.
What's your alternative?
Just curious, with a 26 preamp draft on the bench...
Regards,
Remco
- --
http://listen.to/rmsaudio
=========================================================================
From: Robert C Chambers <rchamber@norwich.edu>
Subject: Re: [JN] 26-46 amp
Date: Tue, 7 Nov 2000 12:16:35 -0500 (EST)
Source: Sound Digest Archive v02.n724
Hi Carter, Joes-
This amp has me inspired and curious. Enough for me to bid on some Hytron
46s on eBay, and win. So now I've *got* to do something. I need a little
help to understand this circuit. I've got so many questions that I think
I should ask if there is a schematic available?
It is interesting to note in the RCA data for the type 46 that it was
intended to be used triode connected (G2 connected to anode) Class A1 as
a driver for PP46s in Class B - an all-tubes-the-same amplifier. Also of
interest is that the 46 is called a "double-grid power amplifier tube",
not a tetrode, and typical operation is shown for two tubes in Class B PP
at zero bias and with the two grids connected together at the socket
(another way to triode-connect the tube). Phase splitting is accomplished
with a transformer with a (primary/half secondary) voltage ratio of 2.2.
On Sun, 22 Oct 2000, Carter Hendricks wrote:
.
.
.
> I'll wait a while longer before talking about the 46 PP amp.
> I plan to try a different driver...
Aw come on, give us at least a sketch! :-)
What was the previous driver?
.
.
.
> 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.
I'm wondering about driving with a 46, transformer coupled. Just
dreaming.
> 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].
So the 46 grid and 26 plate are at 92 volts? 46 plate at 345 volts?
46 plate to cathode is thus 220 volts, not 250, no?
> 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.
That must be a Carbon Comp 2w. Hum pot on the 26?
> 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.
Is this A18 the "Nickel Wonder" that's no longer available?
What can be substituted?
.
.
.
> 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,
I'm lost. Is this along the lines of the Ronan Regulator?
I started trying to draw the schematic from your description here but I
burned out. I'll try again later if you don't have one.
.
.
.
> 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 ...
Well, there's a big dump on Hammond - can you explain further what the
results would be?
What choke alternatives do you suggest?
> The strength and tone "down there" is better with my
> 46 PP amp. That one has real control of double bass
> tone...
Was the 46 PP "presented" here on the JoeList, or is this the one we're
waiting for, referred to above?
.
.
.
> * 27 + 42, but both MQ choke loaded, to 2A3.
We're waiting...:-)
Regards,
Robert
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: RE: [JN] 26-46 amp
Date: Tue, 7 Nov 2000 12:22:00 -0600
Source: Sound Digest Archive v02.n724
Hi Robert--
Thanks for the interest. The 26-46 is a nice little
amp and I really enjoy it. Please remember that it
is exactly 1.25 watts.
> I've got so many questions that I think
> I should ask if there is a schematic available?
This is a dilemma for me. The amplifier design was
inspired by Shishido's driver circuit, published in
his wonderful book. I assume that the book is still
available, from April Audio or from Koji, and while
I don't have qualms describing the circuit...
And while you're at it, buy Atarashi's book, too!
I was studying it again this morning, as I waited
in line to cast my hesitant but important vote.
{Oh & just ignore all that class B stuff. For our
purposes, think of the 46 as a slightly different,
and maybe slightly sweeter 45}
> > I'll wait a while longer before talking about
> > the 46 PP amp.
> > I plan to try a different driver...
>
> Aw come on, give us at least a sketch! :-)
> What was the previous driver?
I didn't have good luck with the Allied as a phase
splitter, and am working on another scheme with
phase split at the input and a lot of PP DHT's.
Oh, and the 46 outputs are class A, not class B.
> > 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.
>
> I'm wondering about driving with a 46, transformer
> coupled. Just
> dreaming.
Different amp. 26 direct coupled to 46, IT [or choke
load 1st 46] to 46. But there is a direct-ness or
clarity to the 26-46 which I would not want to lose.
I will try one of Mikey's small plate chokes on the
26, with adjusted voltages, to get a little more
force and gain from the 26.
[I tried to use some of the lower/hotter operating
points which I like for the 26, but the gain/headroom
distribution is pretty tight and I wound up back where
Shishido started].
Or were you thinking of 46 to 46? same gain
problems now worse. And the 26 brings some magic.
My friend tells me that the 26 magic is a little
bit of what comes from the 205D. This sound is
open and light, not "tubey" or warm or whatever...
> Hum pot on the 26?
No. The 26 must have a current-regulated DC
supply, worked up like the Ronan Reg. Tom's
efforts made it easy, but a little perf board
will be just fine. I mounted the 2nd/current
reg on the aluminum chassis. This requires
isolation washers.
>
> > The 26 doesn't have enough voltage gain to
> > drive the 46 to full glory.
> ??????????????????????????????
The 26 has a gain of around 6, 2 volts in = 12,
not as much as the 33 vgk the 46 requires for
full power. 3:1 stepup would be nice. The
choke load on the 26 would help, too. For now
my line stage makes up the difference.
> Is this A18 the "Nickel Wonder"
No!
> What can be substituted?
The A18 is a UTC small signal transformer,
20K:80K I think. These puppies are getting a little
expensive on ebay. But this is not an amp which
can be built with junkbox parts.
Someone mentioned STC amps today. I've built some,
and I am amazed at how good sucky parts can sound
in an STC amp. But this 26-46 amp requires the
three forces which Gordon has talked about: circuit,
parts and layout.
But it is worth it : ).
> > I know what a cheap [Hammond] filter choke
> > would do to this amp and the music,
> Well, there's a big dump on Hammond -
I know what I hear. I think part of the problem
is that all the cheap stuff is cheaply made.
Well, duh. But the tone is harsh and nasty. Try
using a Hammond as a plate choke. It sucks, and
the problem is not simply the design capacitance
issues. But a filter choke is still in the same
place in the circuit, just hidden a bit by the
cap.
> What choke alternatives do you suggest?
What are Electraprints like?
I like the sound of the MQ stuff. The Black Art
transformers are perfect for this amp, or you
can get a pair of DS050.
--Carter
=========================================================================
From: Dan Marshall <mdaniel7@uswest.net>
Subject: Re: [JN] 26-46 amp
Date: Tue, 07 Nov 2000 12:46:45 +0000
Source: Sound Digest Archive v02.n724
Carter Hendricks wrote:
>
> Hi Robert--
>
<snip>
>
> The A18 is a UTC small signal transformer,
> 20K:80K I think. These puppies are getting a little
> expensive on ebay. But this is not an amp which
> can be built with junkbox parts.
<snip>
--Carter
Say, I have three A-18s in nice cond which I have considered listing on
eBay, but haven't gotten around to it yet. They sell there for around
$80 each, the last pair for a bit more. I might be convinced to sell
them, either one piece, or a pair, if someone wants the odd piece. As I
recall they are 15k PP to 80k GG. These are the grey models with
riveted-on nameplate. These are a bit earlier and considered better
than the later printed versions, at least this is what I have heard.
Dan Marshall
=========================================================================
From: "Larry D. Moore" <l-moore@onu.edu>
Subject: Re: [JN] 26-46 amp
Date: Tue, 07 Nov 2000 13:26:42 -0500
Source: Sound Digest Archive v02.n724
Right now I am listening to a 5842-46 amp that I built which I've descibed
on the list in the past. One OPT you might consider is the one that i had
Jack at Electraprint make for me. It is 4k8 with either a 8 or 16 ohm
secondary. I opted for the 16 ohm version for my speakers. The -1dB
points are 20 to 20KHz. They are REALLY nice, especially for the price.
L.D. Moore
=========================================================================
From: Robert C Chambers <rchamber@norwich.edu>
Subject: Re: [JN] 26-46 amp
Date: Tue, 7 Nov 2000 14:50:39 -0500 (EST)
Source: Sound Digest Archive v02.n724
Hi Raymond-
On Tue, 7 Nov 2000, Raymond Koonce wrote:
> Robert,
>
> I've gotten this message 10 times so far.
If I knew that I did something wrong I would change my ways and apologise.
I have *no idea* what might have caused your overdose. I sent it only
once. But you have my sympathy!
Anyone else have this problem? Or know what might have caused it?
Regards,
Robert
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: RE: [JN] 26-46 amp
Date: Tue, 07 Nov 2000 15:55:17 -0500
Source: Sound Digest Archive v02.n724
no.
i only got it once ;)
> ----------
> From: Robert C Chambers[SMTP:rchamber@norwich.edu]
> Sent: Tuesday, November 07, 2000 2:50 PM
> To: JOELIST
> Subject: Re: [JN] 26-46 amp
>
>
> Hi Raymond-
>
> On Tue, 7 Nov 2000, Raymond Koonce wrote:
>
> > Robert,
> >
> > I've gotten this message 10 times so far.
>
> If I knew that I did something wrong I would change my ways and apologise.
> I have *no idea* what might have caused your overdose. I sent it only
> once. But you have my sympathy!
>
> Anyone else have this problem? Or know what might have caused it?
>
> Regards,
>
> Robert
>
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: RE: [JN] 26-46 amp
Date: Tue, 07 Nov 2000 15:55:43 -0500
Source: Sound Digest Archive v02.n724
no. i only got it once ;) ;)
> ----------
> From: Robert C Chambers[SMTP:rchamber@norwich.edu]
> Sent: Tuesday, November 07, 2000 2:50 PM
> To: JOELIST
> Subject: Re: [JN] 26-46 amp
>
>
> Hi Raymond-
>
> On Tue, 7 Nov 2000, Raymond Koonce wrote:
>
> > Robert,
> >
> > I've gotten this message 10 times so far.
>
> If I knew that I did something wrong I would change my ways and apologise.
> I have *no idea* what might have caused your overdose. I sent it only
> once. But you have my sympathy!
>
> Anyone else have this problem? Or know what might have caused it?
>
> Regards,
>
> Robert
>
=========================================================================
From: "Danielak, Robert M" <robert.m.danielak@lmco.com>
Subject: RE: [JN] 26-46 amp
Date: Tue, 07 Nov 2000 15:56:21 -0500
Source: Sound Digest Archive v02.n724
no. i only got it once. ;) ;) ;)
> ----------
> From: Robert C Chambers[SMTP:rchamber@norwich.edu]
> Sent: Tuesday, November 07, 2000 2:50 PM
> To: JOELIST
> Subject: Re: [JN] 26-46 amp
>
>
> Hi Raymond-
>
> On Tue, 7 Nov 2000, Raymond Koonce wrote:
>
> > Robert,
> >
> > I've gotten this message 10 times so far.
>
> If I knew that I did something wrong I would change my ways and apologise.
> I have *no idea* what might have caused your overdose. I sent it only
> once. But you have my sympathy!
>
> Anyone else have this problem? Or know what might have caused it?
>
> Regards,
>
> Robert
>
=========================================================================
From: Raymond Koonce <rkoonce@tyler.net>
Subject: Re: [JN] 26-46 amp
Date: Tue, 07 Nov 2000 19:23:06 -0600
Source: Sound Digest Archive v02.n724
Hi Robert,
Seems it was an ISP problem. All taken care of now. I got that message
probably 50 times and nothing afterward. Go figure.
Anyway, it's a great thread. Keep us posted.
Raymond, lurking
Robert C Chambers wrote:
> Hi Raymond-
>
> On Tue, 7 Nov 2000, Raymond Koonce wrote:
>
> > Robert,
> >
> > I've gotten this message 10 times so far.
>
> If I knew that I did something wrong I would change my ways and apologise.
> I have *no idea* what might have caused your overdose. I sent it only
> once. But you have my sympathy!
>
> Anyone else have this problem? Or know what might have caused it?
>
> Regards,
>
> Robert
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: [JN] RE: 26-46 Amplifier/Shishido's Book
Date: Thu, 17 May 2001 13:30:23 -0500
Source: Sound Digest Archive v02.n886
Robert--
> I have just received Shishido's... book from
> Koji.
cool!
The variation which I used is on page 155.
I used current regulation for the 26's fils
and a hum pot for the 46. I use the Black
Art opt's which are optimized for the ~20mA
of the 46. The sound is very clear. It makes
a good amp by itself, but it needs a step up
and/or a high gain line stage. Or the 26-46
can be used as a driver for another tube,
an 845 or even another 46.
--Carter
=========================================================================
From: rchamber@norwich.edu
Subject: [JN] 26-46 Amplifier/Shishido's Book
Date: Thu, 17 May 2001 18:20:44 GMT
Source: Sound Digest Archive v02.n886
Hi Carter-
I have just received Shishido's SE Amps Using Transmitting Tubes book from
Koji. Definitely not like reading Terman!!!
I remember you referred to it when I asked about the topology of your 26-46
amplifier. I've skimmed enough to have found a couple of examples using
26-46 as driver for a TT output. But, I'm wondering, could you point me to
a page on which to begin my contemplation?
Best Regards,
Robert
=========================================================================
From: "Polaris" <jimd@polaris.net>
Subject: [JN] 26 hum
Date: Thu, 22 Mar 2001 11:19:39 -0500
Source: Sound Digest Archive v02.n839
I'm using some 1.5v batteries for filament supplies on my breadboarded 26
linestage until I work out the Ronanreg problems. Hum level is still
obnoxious with batteries so the source must be elsewhere. The only way I
can eliminate the hum is to stand to one side of the linestage, touch the
rear RCA jacks with one hand and cup my other hand around the right tube
(I'm not kidding!). Lifting either hand brings back the hum, but worse
when I lift the hand touching the RCA jacks. I tried a separate jumper
between the amp and linestage ground but it did not help. A different pair
of 26s also did not help.
What's going on?
Based on some short listening sessions, it's intersting that the 26s sound
nice but only a marginal improvement over my simple cap coupled 5687 with
tantalums, BGs and Hovland output cap. I'm not sure I could differentiate
in a blind test. Kinda surprised me.
Jim Dudley
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: [JN] 26 hum
Date: Thu, 22 Mar 2001 16:25:21 +0000 (GMT)
Source: Sound Digest Archive v02.n839
RF oscillation? This can get hum modulated to give all sorts of wierd
effects.
Waft a cro probe around and see if you can pick anything up.
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: "J. Gordon Rankin" <waudio@cinti.net>
Subject: Re: [JN] 26 hum
Date: Thu, 22 Mar 01 12:30:05 -0500
Source: Sound Digest Archive v02.n839
Jim,
Try this, take a jumper from signal ground and touch it to the ground of
the RCA see what happens, it may be what is called pin one noise.
Gordon
=====> Wavelength Audio, ltd. <=====
mailto:waudio@cinti.net
mailto:wavelength@fuse.net
http://www.WavelengthAudio.com
ph.fx. 513-271-4186 USA
=========================================================================
From: David Home <David_Home@creoscitex.com>
Subject: RE: [JN] 26 hum
Date: Mon, 26 Mar 2001 09:08:58 +0200
Source: Sound Digest Archive v02.n843
Hi Jim.
First, have you tried shorting the grid to the cathode right at the tube?
Maybe some RF is getting in somewhere...
Secondly, I would not rule out the battery right off the bat. Others have
noted strange sounds coming from battery biased triodes, usually cured by
using different ( better ) batteries.
Regards, David
- -----Original Message-----
From: Polaris [mailto:jimd@polaris.net]
Sent: Thursday, March 22, 2001 5:20 PM
To: Joenet (E-mail)
Subject: [JN] 26 hum
I'm using some 1.5v batteries for filament supplies on my breadboarded 26
linestage until I work out the Ronanreg problems. Hum level is still
obnoxious with batteries so the source must be elsewhere. The only way I
can eliminate the hum is to stand to one side of the linestage, touch the
rear RCA jacks with one hand and cup my other hand around the right tube
(I'm not kidding!). Lifting either hand brings back the hum, but worse
when I lift the hand touching the RCA jacks. I tried a separate jumper
between the amp and linestage ground but it did not help. A different pair
of 26s also did not help.
What's going on?
Based on some short listening sessions, it's intersting that the 26s sound
nice but only a marginal improvement over my simple cap coupled 5687 with
tantalums, BGs and Hovland output cap. I'm not sure I could differentiate
in a blind test. Kinda surprised me.
Jim Dudley
=========================================================================
From: "Jim Dudley" <jimd@polaris.net>
Subject: [JN] 26 linestage
Date: Sat, 3 Mar 2001 22:16:26 -0500
Source: Sound Digest Archive v02.n825
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Has anyone been able to build a quiet enough 26 linestage? I recently =
breadboarded the cap coupled version of Jim de Kort's design using the 3 =
stage Ronanreg boards for the dc filament supply. Voltages were spot =
on and the sound is really good, but the hum is unbearable. I got 35mv =
on one channel and 75mv on the other when I get less than 2-3mv on the =
same amp using my 5687 linestage. Power supply is LCLC. =20
Thanks,
Jim Dudley
- ------=_NextPart_000_0004_01C0A42F.9675E1E0
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<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
<META content=3D'"MSHTML 4.72.3110.7"' name=3DGENERATOR>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000 size=3D2>Has anyone been able to build a =
quiet enough 26=20
linestage? I recently breadboarded the cap coupled version of Jim =
de=20
Kort's design using the 3 stage Ronanreg boards for the dc filament=20
supply. Voltages were spot on and the sound is really good, =
but the=20
hum is unbearable. I got 35mv on one channel and 75mv on the other =
when I=20
get less than 2-3mv on the same amp using my 5687 linestage. Power =
supply is=20
LCLC. </FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Thanks,</FONT></DIV>
<DIV><FONT size=3D2>Jim Dudley</FONT></DIV></BODY></HTML>
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=========================================================================
From: Mathias Spaeh <MSpaeh@gmx.de>
Subject: Re: [JN] 26 linestage
Date: Sun, 4 Mar 2001 18:50:25 +0100 (MET)
Source: Sound Digest Archive v02.n825
i can only agree to this, i tried it also with a Ronan reg and about
350000uF capacity on the DC filament. For B+ supply
i tried a regulated LCLC with two OC3 in series, to get the B+ absolut
quiet. The hum level was still too much for my Klipschorns.
I believe with all battery suplies, like Jim did, this linestage will work.
But the biggest problem was the microfonie of this tubes. The result was an
auction on ebay.
Now i'm happy with my Euridice linestage. Absolut quit and nice to listen.
If you really want to go to direct heated tubes, try the
AV8 from Vaic. It is much easier to handle and sounds great.
Mathias
- --
Sent through GMX FreeMail - http://www.gmx.net
=========================================================================
From: =?iso-8859-1?Q?Bj=F8rn_Aaholm?= <bjorn@vt52.com>
Subject: SV: [JN] 26 linestage
Date: Sun, 4 Mar 2001 22:04:49 +0100
Source: Sound Digest Archive v02.n825
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Hello Jim.
I have a quiet 26 linestage as well, battery supplied filaments though.
With current regulated filaments you should be able to get low hum levels as
well though. How large a cap do you use for cathode bypass? This really has
a huge impact on the hum when using anything but batteries.
Regards,
Bjørn Aaholm
http://listen.to/aaholm (here you can find info on my linestage)
-----Oprindelig meddelelse-----
Fra: owner-sound@lists.io.com [mailto:owner-sound@lists.io.com]På vegne af
Jim Dudley
Sendt: 4. marts 2001 04:16
Til: Joenet (E-mail)
Emne: [JN] 26 linestage
Has anyone been able to build a quiet enough 26 linestage? I recently
breadboarded the cap coupled version of Jim de Kort's design using the 3
stage Ronanreg boards for the dc filament supply. Voltages were spot on
and the sound is really good, but the hum is unbearable. I got 35mv on one
channel and 75mv on the other when I get less than 2-3mv on the same amp
using my 5687 linestage. Power supply is LCLC.
Thanks,
Jim Dudley
- ------=_NextPart_000_0000_01C0A4F7.2193DDF0
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<HTML><HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type>
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<BODY bgColor=3D#ffffff>
<DIV><FONT face=3DArial size=3D2><SPAN class=3D375460121-04032001>Hello=20
Jim.</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN=20
class=3D375460121-04032001></SPAN></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><SPAN class=3D375460121-04032001>I have =
a quiet 26=20
linestage as well, battery supplied filaments =
though.</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN class=3D375460121-04032001>With =
current=20
regulated filaments you should be able to get low hum levels as well =
though. How=20
large a cap do you use for cathode bypass? This really has a huge impact =
on the=20
hum when using anything but batteries.</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN=20
class=3D375460121-04032001></SPAN></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><SPAN=20
class=3D375460121-04032001>Regards,</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN =
class=3D375460121-04032001>Bj=F8rn=20
Aaholm</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN class=3D375460121-04032001><A=20
href=3D"http://listen.to/aaholm">http://listen.to/aaholm</A> (here you =
can find=20
info on my linestage)</SPAN></FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 2px solid; MARGIN-LEFT: 5px; MARGIN-RIGHT: =
0px; PADDING-LEFT: 5px">
<DIV align=3Dleft class=3DOutlookMessageHeader dir=3Dltr><FONT =
face=3DTahoma=20
size=3D2>-----Oprindelig meddelelse-----<BR><B>Fra:</B> =
owner-sound@lists.io.com=20
[mailto:owner-sound@lists.io.com]<B>P=E5 vegne af </B>Jim=20
Dudley<BR><B>Sendt:</B> 4. marts 2001 04:16<BR><B>Til:</B> Joenet=20
(E-mail)<BR><B>Emne:</B> [JN] 26 linestage<BR><BR></DIV></FONT>
<DIV><FONT size=3D2>Has anyone been able to build a quiet enough 26=20
linestage? I recently breadboarded the cap coupled version of =
Jim de=20
Kort's design using the 3 stage Ronanreg boards for the dc filament=20
supply. Voltages were spot on and the sound is really =
good, but=20
the hum is unbearable. I got 35mv on one channel and 75mv on the =
other=20
when I get less than 2-3mv on the same amp using my 5687 linestage. =
Power=20
supply is LCLC. </FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Thanks,</FONT></DIV>
<DIV><FONT size=3D2>Jim Dudley</FONT></DIV></BLOCKQUOTE></BODY></HTML>
- ------=_NextPart_000_0000_01C0A4F7.2193DDF0--
=========================================================================
From: David Home <David_Home@creoscitex.com>
Subject: RE: [JN] 26 linestage
Date: Sun, 4 Mar 2001 23:18:30 +0100
Source: Sound Digest Archive v02.n826
Hello Mathias.
I am sorry to hear that you had bad luck with the 26. However, I do think
that it can be tamed as I have done it.
I used a single stage of voltage regulation followed by a current regulator.
B+ is regulated with a OA2 per channel.
I am more interested in your Euridice preamp and other preamp experiences.
The article about it is in one of the issues of SP I do not have. What tube
does it use?
Also, do you have experience with the AV8 ( or AV20 ) as a line stage?
Any comments appreciated.
Regards, David
- -----Original Message-----
From: Mathias Spaeh [mailto:MSpaeh@gmx.de]
Sent: Sunday, March 04, 2001 6:50 PM
To: sound@lists.io.com
Subject: Re: [JN] 26 linestage
i can only agree to this, i tried it also with a Ronan reg and about
350000uF capacity on the DC filament. For B+ supply
i tried a regulated LCLC with two OC3 in series, to get the B+ absolut
quiet. The hum level was still too much for my Klipschorns.
I believe with all battery suplies, like Jim did, this linestage will work.
But the biggest problem was the microfonie of this tubes. The result was an
auction on ebay.
Now i'm happy with my Euridice linestage. Absolut quit and nice to listen.
If you really want to go to direct heated tubes, try the
AV8 from Vaic. It is much easier to handle and sounds great.
Mathias
- --
Sent through GMX FreeMail - http://www.gmx.net
=========================================================================
From: David Home <David_Home@creoscitex.com>
Subject: RE: [JN] 26 linestage
Date: Sun, 4 Mar 2001 23:18:32 +0100
Source: Sound Digest Archive v02.n826
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this format, some or all of this message may not be legible.
- ------_=_NextPart_001_01C0A4F9.0C5430F0
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charset="iso-8859-1"
Hi Jim.
I am surprised to hear that you are having hum problems when using the Ronan
style regulators on the 26.
My line stage is dead quite, no AC measured at all on the output or heard.
I used a simplified version of CCS heating. A simple CLC filter, then a
single stage of voltage regulation and then the current regulation. I am a
cheapskate and used one regulator chain for both tubes. I therefore had to
also parallel the biasing, which is a 2K resistor for both channels bypassed
with a 470uF BG. B+ is LC followed by a OA2 per channel. Output is through
15K:200 UTC A-25 line output transformers which because of the step down
ratio also steps down any hum I suppose.
Another person has suggested checking that the cathode is well bypassed and
I can vouch for that. I would also suggest checking the filament supply
itself when running and check to be sure the regulators are functioning
properly. There should be absolutely NO AC ripple at all on the filament
supply.
Good luck and regards,
David
- -----Original Message-----
From: Jim Dudley [mailto:jimd@polaris.net]
Sent: Sunday, March 04, 2001 4:16 AM
To: Joenet (E-mail)
Subject: [JN] 26 linestage
Has anyone been able to build a quiet enough 26 linestage? I recently
breadboarded the cap coupled version of Jim de Kort's design using the 3
stage Ronanreg boards for the dc filament supply. Voltages were spot on
and the sound is really good, but the hum is unbearable. I got 35mv on one
channel and 75mv on the other when I get less than 2-3mv on the same amp
using my 5687 linestage. Power supply is LCLC.
Thanks,
Jim Dudley
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<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=389191322-04032001>Hi
Jim.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=389191322-04032001>I am
surprised to hear that you are having hum problems when using the Ronan style
regulators on the 26. </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=389191322-04032001>My
line stage is dead quite, no AC measured at all on the output or
heard.</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=389191322-04032001>I used
a simplified version of CCS heating. A simple CLC filter, then a single stage of
voltage regulation and then the current regulation. I am a cheapskate and used
one regulator chain for both tubes. I therefore had to also parallel the
biasing, which is a 2K resistor for both channels bypassed with a 470uF BG. B+
is LC followed by a OA2 per channel. Output is through 15K:200 UTC A-25 line
output transformers which because of the step down ratio also steps down any hum
I suppose. </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=389191322-04032001>Another person has suggested checking that the cathode
is well bypassed and I can vouch for that. I would also suggest checking the
filament supply itself when running and check to be sure the regulators are
functioning properly. There should be absolutely NO AC ripple at all on the
filament supply. </SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN class=389191322-04032001>Good
luck and regards,</SPAN></FONT></DIV>
<DIV><FONT color=#0000ff face=Arial size=2><SPAN
class=389191322-04032001>David</SPAN></FONT></DIV>
<BLOCKQUOTE style="MARGIN-RIGHT: 0px">
<DIV align=left class=OutlookMessageHeader dir=ltr><FONT face=Tahoma
size=2>-----Original Message-----<BR><B>From:</B> Jim Dudley
[mailto:jimd@polaris.net]<BR><B>Sent:</B> Sunday, March 04, 2001 4:16
AM<BR><B>To:</B> Joenet (E-mail)<BR><B>Subject:</B> [JN] 26
linestage<BR><BR></DIV></FONT>
<DIV><FONT color=#000000 size=2>Has anyone been able to build a quiet enough
26 linestage? I recently breadboarded the cap coupled version of Jim de
Kort's design using the 3 stage Ronanreg boards for the dc filament
supply. Voltages were spot on and the sound is really good, but
the hum is unbearable. I got 35mv on one channel and 75mv on the other
when I get less than 2-3mv on the same amp using my 5687 linestage. Power
supply is LCLC. </FONT></DIV>
<DIV><FONT color=#000000 size=2></FONT> </DIV>
<DIV><FONT size=2>Thanks,</FONT></DIV>
<DIV><FONT size=2>Jim Dudley</FONT></DIV></BLOCKQUOTE></BODY></HTML>
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From: "Polaris" <jimd@polaris.net>
Subject: Re: [JN] 26 linestage
Date: Mon, 5 Mar 2001 11:24:42 -0500
Source: Sound Digest Archive v02.n826
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Hi Bjorn,
I have the cathode resistor bypassed with the specified 470uf cap. =20
Jim
-----Original Message-----
From: Bj=F8rn Aaholm <bjorn@vt52.com>
To: Jim Dudley <jimd@polaris.net>; Joenet (E-mail) =
<sound@lists.io.com>
Date: Sunday, March 04, 2001 4:23 PM
Subject: SV: [JN] 26 linestage
=20
=20
Hello Jim.
=20
I have a quiet 26 linestage as well, battery supplied filaments =
though.
With current regulated filaments you should be able to get low hum =
levels as well though. How large a cap do you use for cathode bypass? =
This really has a huge impact on the hum when using anything but =
batteries.
=20
Regards,
Bj=F8rn Aaholm
http://listen.to/aaholm (here you can find info on my linestage)
-----Oprindelig meddelelse-----
Fra: owner-sound@lists.io.com =
[mailto:owner-sound@lists.io.com]P=E5 vegne af Jim Dudley
Sendt: 4. marts 2001 04:16
Til: Joenet (E-mail)
Emne: [JN] 26 linestage
=20
=20
Has anyone been able to build a quiet enough 26 linestage? I =
recently breadboarded the cap coupled version of Jim de Kort's design =
using the 3 stage Ronanreg boards for the dc filament supply. Voltages =
were spot on and the sound is really good, but the hum is unbearable. I =
got 35mv on one channel and 75mv on the other when I get less than 2-3mv =
on the same amp using my 5687 linestage. Power supply is LCLC. =20
=20
Thanks,
Jim Dudley
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">
<HTML>
<HEAD>
<META content=3Dtext/html;charset=3Diso-8859-1 =
http-equiv=3DContent-Type><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 =
Transitional//EN">
<META content=3D'"MSHTML 4.72.2106.6"' name=3DGENERATOR>
</HEAD>
<BODY bgColor=3D#ffffff>
<DIV><FONT color=3D#000000 size=3D2>Hi Bjorn,</FONT></DIV>
<DIV><FONT color=3D#000000 size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>I have the cathode resistor bypassed with the =
specified 470uf=20
cap. </FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Jim</FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; PADDING-LEFT: =
5px">
<DIV><FONT face=3DArial size=3D2><B>-----Original =
Message-----</B><BR><B>From:=20
</B>Bjørn Aaholm <<A=20
href=3D"mailto:bjorn@vt52.com">bjorn@vt52.com</A>><BR><B>To: =
</B>Jim Dudley=20
<<A href=3D"mailto:jimd@polaris.net">jimd@polaris.net</A>>; =
Joenet=20
(E-mail) <<A=20
=
href=3D"mailto:sound@lists.io.com">sound@lists.io.com</A>><BR><B>Date:=
=20
</B>Sunday, March 04, 2001 4:23 PM<BR><B>Subject: </B>SV: [JN] 26=20
linestage<BR><BR></DIV></FONT>
<DIV><FONT face=3DArial size=3D2><SPAN =
class=3D375460121-04032001>Hello=20
Jim.</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN=20
class=3D375460121-04032001></SPAN></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><SPAN class=3D375460121-04032001>I =
have a quiet=20
26 linestage as well, battery supplied filaments =
though.</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN =
class=3D375460121-04032001>With current=20
regulated filaments you should be able to get low hum levels as well =
though.=20
How large a cap do you use for cathode bypass? This really has a =
huge impact=20
on the hum when using anything but batteries.</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN=20
class=3D375460121-04032001></SPAN></FONT> </DIV>
<DIV><FONT face=3DArial size=3D2><SPAN=20
class=3D375460121-04032001>Regards,</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN =
class=3D375460121-04032001>Bjørn=20
Aaholm</SPAN></FONT></DIV>
<DIV><FONT face=3DArial size=3D2><SPAN class=3D375460121-04032001><A =
href=3D"http://listen.to/aaholm">http://listen.to/aaholm</A> (here =
you can=20
find info on my linestage)</SPAN></FONT></DIV>
<BLOCKQUOTE=20
style=3D"BORDER-LEFT: #000000 solid 2px; MARGIN-LEFT: 5px; =
MARGIN-RIGHT: 0px; PADDING-LEFT: 5px">
<DIV align=3Dleft class=3DOutlookMessageHeader dir =3D ltr><FONT =
face=3DTahoma=20
size=3D2>-----Oprindelig meddelelse-----<BR><B>Fra:</B>=20
owner-sound@lists.io.com =
[mailto:owner-sound@lists.io.com]<B>På=20
vegne af </B>Jim Dudley<BR><B>Sendt:</B> 4. marts 2001=20
04:16<BR><B>Til:</B> Joenet (E-mail)<BR><B>Emne:</B> [JN] 26=20
linestage<BR><BR></DIV></FONT>
<DIV><FONT size=3D2>Has anyone been able to build a quiet enough =
26=20
linestage? I recently breadboarded the cap coupled version =
of Jim=20
de Kort's design using the 3 stage Ronanreg boards for the dc =
filament=20
supply. Voltages were spot on and the sound is =
really good,=20
but the hum is unbearable. I got 35mv on one channel and =
75mv on=20
the other when I get less than 2-3mv on the same amp using my =
5687=20
linestage. Power supply is LCLC. </FONT></DIV>
<DIV><FONT size=3D2></FONT> </DIV>
<DIV><FONT size=3D2>Thanks,</FONT></DIV>
<DIV><FONT size=3D2>Jim=20
Dudley</FONT></DIV></BLOCKQUOTE></BLOCKQUOTE></BODY></HTML>
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From: =?iso-8859-1?Q?Bj=F8rn_Aaholm?= <bjorn@vt52.com>
Subject: SV: [JN] 26 linestage
Date: Tue, 6 Mar 2001 08:08:08 +0100
Source: Sound Digest Archive v02.n827
Jim...
With a bypass of 470uF you should have very little if any hum with the
current regulated filament supplies. I hope Tom Ronan follows up on what
Carter posted about the possible ground loop, he knows his regulators best
:-)
Do you have the regulators on heatsinks? These animals go into protection
mode if overheated and when wired as current regulators I should think you'd
still have voltage on the output although I could be wring. If there is
voltage while the regulator is in protection mode it will most definately
NOT be regulated (very well).
Please don't give up, the 26 sounds so sweet and the hum CAN be killed.
Stay tuned... I'm experimenting with AC on the filaments in my 26 linestage.
If it ever works out with bearable hum I'll let you know (hint: it takes a
bit more than just a hum balancing pot to get this baby quiet as you might
imagine - Thanks Steve Bench, for you insightful info on your site).
Hope to see MANY of you guys in Århus this summer...
regards,
Bjørn Aaholm
=========================================================================
From: "Mathias Spaeh" <mspaeh@gmx.de>
Subject: Re: [JN] 26 linestage
Date: Tue, 6 Mar 2001 19:51:31 +0100
Source: Sound Digest Archive v02.n827
Hi David,
it is originally using a 5842 which i'm using also. There are lots of more
ore less
identical Euridice linestages in the web.
I used the power supply, which i wanted originally use for 26 linestage.
A Ronan reg for the filaments and a regulated B+ with one OD3 to
give me about 156V, which was ok for the 26 and also for the 5842.
On the cathode i'm using to NiMh batteries in series for the bias voltage of
the 5842.
For the output transfomer i'm using a German one with 10K:300 Ohm
impedance.
You can easiely adapt the linestage to use different tubes like the 6C45
or even a direct heated tube like the AV20.
In my setup there is no capacitor, where music must flow through.
Please keep in mind that the output transfomers are very sensitiv
in picking up hum.
Mathias
- ----- Original Message -----
From: "David Home" <David_Home@creoscitex.com>
To: "Mathias Spaeh" <MSpaeh@gmx.de>; <sound@lists.io.com>
Sent: Sunday, March 04, 2001 11:18 PM
Subject: RE: [JN] 26 linestage
> Hello Mathias.
> I am sorry to hear that you had bad luck with the 26. However, I do think
> that it can be tamed as I have done it.
> I used a single stage of voltage regulation followed by a current
regulator.
> B+ is regulated with a OA2 per channel.
>
> I am more interested in your Euridice preamp and other preamp experiences.
> The article about it is in one of the issues of SP I do not have. What
tube
> does it use?
> Also, do you have experience with the AV8 ( or AV20 ) as a line stage?
> Any comments appreciated.
> Regards, David
>
> -----Original Message-----
> From: Mathias Spaeh [mailto:MSpaeh@gmx.de]
> Sent: Sunday, March 04, 2001 6:50 PM
> To: sound@lists.io.com
> Subject: Re: [JN] 26 linestage
>
>
> i can only agree to this, i tried it also with a Ronan reg and about
> 350000uF capacity on the DC filament. For B+ supply
> i tried a regulated LCLC with two OC3 in series, to get the B+ absolut
> quiet. The hum level was still too much for my Klipschorns.
> I believe with all battery suplies, like Jim did, this linestage will
work.
> But the biggest problem was the microfonie of this tubes. The result was
an
> auction on ebay.
> Now i'm happy with my Euridice linestage. Absolut quit and nice to listen.
> If you really want to go to direct heated tubes, try the
> AV8 from Vaic. It is much easier to handle and sounds great.
>
> Mathias
>
> --
> Sent through GMX FreeMail - http://www.gmx.net
>
=========================================================================
From: "Farwell-Clay" <wclay@mediaone.net>
Subject: [JN] 26 linestage hum
Date: Tue, 6 Mar 2001 11:12:28 -0500
Source: Sound Digest Archive v02.n827
Jim,
A friend of mine built a Ronanreg 26 linestage that is DEAD quiet. It
certainly can be done. He found that each board needed to be fed from its
own separate filament transformer. In fact, he claims that using the
filament winding on a combined power transformer for one of them wasn't
isolated enough. It sure works, though.
Regards,
Walter Clay
=========================================================================
From: "Miglioranza, Richard (Sudbury)" <RMiglioranza@inco.com>
Subject: RE: [JN] 26 linestage hum
Date: Tue, 6 Mar 2001 12:09:44 -0500
Source: Sound Digest Archive v02.n827
Walter,
I had the same experience with the 26. Once the Ronan reg. boards
were fed from separate filament trannies, it was hum free.
While on this topic, I have a pair of fully stuffed Ronan boards for the 26
for sale in case anyone is interested. $50 for the pair plus shipping.
Thanks,
Ritchie
> ----------
> From: Farwell-Clay[SMTP:wclay@mediaone.net]
> Sent: Tuesday, March 06, 2001 11:12 AM
> To: sound@lists.io.com
> Subject: [JN] 26 linestage hum
>
> Jim,
> A friend of mine built a Ronanreg 26 linestage that is DEAD quiet. It
> certainly can be done. He found that each board needed to be fed from its
> own separate filament transformer. In fact, he claims that using the
> filament winding on a combined power transformer for one of them wasn't
> isolated enough. It sure works, though.
> Regards,
> Walter Clay
>
=========================================================================
From: "Polaris" <jimd@polaris.net>
Subject: Re: [JN] 26 linestage hum
Date: Tue, 6 Mar 2001 12:17:28 -0500
Source: Sound Digest Archive v02.n827
Yes, I've had enough comments to believe I've got an uncovered problem.
I'm working with Tom Ronan now to troubleshoot. Thanks for all the
comments. I'll let the list know how it turns out.
BTW Walter, I am using separate FTs.
Jim Dudley
>Jim,
>A friend of mine built a Ronanreg 26 linestage that is DEAD quiet. It
>certainly can be done. He found that each board needed to be fed from its
>own separate filament transformer. In fact, he claims that using the
>filament winding on a combined power transformer for one of them wasn't
>isolated enough. It sure works, though.
>Regards,
>Walter Clay
>
>
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: [JN] 26 pre-amp
Date: Wed, 8 Dec 1999 14:04:34 -0800
Source: Sound Digest Archive v02.n358
Hi #26 fans. I am building a #26 pre-amp now but am going the high tech
route so to speak. I will operate the #26 at 150V/6ma/-11V bias into a CCS
load parellel feeding a UTC A-25 transformer through a 4uF oiler. Filiments
are parelleled and are CCS heated ( thanks to Tom Ronan ). Bias is from a
shared 1K WW bypassed. I am not too worried about the bias method as much
because in parellel feed the signal is returned to the filiment rather then
too ground as in conventional SE operation, bypassing the cathode
resistor/cap. I tried this with a 6SN7 and the UTC A25 in parellel feed and
in SE and prefer the parellel feed. Bass extention is better. The A25 is
normally down -3 dB at 40 Hz with 8ma of DC but it flat to 5 Hz in parellel
feed. I regret not having the A-24 model which I believe was intended for
shunt feed and has no air gap for much more induction.
David Home
Plate Qualification Specialist
Creo Products Inc.,
4225 Kincaid Street,
Burnaby, British Columbia,
Canada, V5G 4P5
Tel. 604.451.2720 Ex. 2397
Fax. 604.437.9891
Email: dhome@creo.com
Website:www.creo.com
-----Original Message-----
From: Henry Platt [mailto:hnplatt@massed.net]
Sent: Wednesday, December 08, 1999 4:10 PM
To: Audio1Nut@aol.com; jim@vt52.com; sound@deliverator.io.com
Subject: Re: [JN] 26 pre-amp
Hi Viwat,
I've been messing with the same type of preamp. Mine is all DC and run on
batteries. two 1.5 volt D cells in series with a voltage trimming pot on the
filaments and a 12 volt rechargable lead acid battery working into a modular
DC supply with an output of 130 volts with 12 volts DC in. Im using UTC
A25s for outputs. 30 ohm resistors from the cathode pins to the positive
terminal of a nicad cathode battery. Sounds nice. it is one quiet preamp.
What are you using for cathode bias?
Regards,
Henry Platt
- ----------
>From: Audio1Nut@aol.com
>To: jim@vt52.com, sound@deliverator.io.com
>Subject: [JN] 26 pre-amp
>Date: Wed, Dec 8, 1999, 11:22 AM
>
> Hi Jim:
> I finnaly get the 26 pre-amp working. I spent week finding the mistake in
my
> pre-amp...the cathode to ground measure 77V!!!!!!!!! The fault is the data
> sheet of the CX326 have pin out wrong!!!(yes) they say that 3 & 4 is
Filament
> instead of 1 & 4..... I remember the big pin as Filament.....so I switch
the
> grid and plate(vice versa).....finally got it to work....BTW: I use Tango
> NP216 as output......very nice sounding......I tried 76(very detail) and
> 5687(warm sounding musical).....I would like both criteria in one.....hope
> that the 26 will answer my prayer(sound promising) The hum (I use AC with
> 50ohm hum pot)did not really border me, but will try to get it
> down......thanks for your inspiration....will report more on sound.
> Viwat
>
=========================================================================
From: Audio1Nut@aol.com
Subject: [JN] 26 pre-amp
Date: Wed, 8 Dec 1999 14:22:42 EST
Source: Sound Digest Archive v02.n358
Hi Jim:
I finnaly get the 26 pre-amp working. I spent week finding the mistake in my
pre-amp...the cathode to ground measure 77V!!!!!!!!! The fault is the data
sheet of the CX326 have pin out wrong!!!(yes) they say that 3 & 4 is Filament
instead of 1 & 4..... I remember the big pin as Filament.....so I switch the
grid and plate(vice versa).....finally got it to work....BTW: I use Tango
NP216 as output......very nice sounding......I tried 76(very detail) and
5687(warm sounding musical).....I would like both criteria in one.....hope
that the 26 will answer my prayer(sound promising) The hum (I use AC with
50ohm hum pot)did not really border me, but will try to get it
down......thanks for your inspiration....will report more on sound.
Viwat
=========================================================================
From: "Henry Platt" <hnplatt@massed.net>
Subject: Re: [JN] 26 pre-amp
Date: Wed, 08 Dec 1999 16:10:24 -0800
Source: Sound Digest Archive v02.n358
Hi Viwat,
I've been messing with the same type of preamp. Mine is all DC and run on
batteries. two 1.5 volt D cells in series with a voltage trimming pot on the
filaments and a 12 volt rechargable lead acid battery working into a modular
DC supply with an output of 130 volts with 12 volts DC in. Im using UTC
A25s for outputs. 30 ohm resistors from the cathode pins to the positive
terminal of a nicad cathode battery. Sounds nice. it is one quiet preamp.
What are you using for cathode bias?
Regards,
Henry Platt
- ----------
>From: Audio1Nut@aol.com
>To: jim@vt52.com, sound@deliverator.io.com
>Subject: [JN] 26 pre-amp
>Date: Wed, Dec 8, 1999, 11:22 AM
>
> Hi Jim:
> I finnaly get the 26 pre-amp working. I spent week finding the mistake in my
> pre-amp...the cathode to ground measure 77V!!!!!!!!! The fault is the data
> sheet of the CX326 have pin out wrong!!!(yes) they say that 3 & 4 is Filament
> instead of 1 & 4..... I remember the big pin as Filament.....so I switch the
> grid and plate(vice versa).....finally got it to work....BTW: I use Tango
> NP216 as output......very nice sounding......I tried 76(very detail) and
> 5687(warm sounding musical).....I would like both criteria in one.....hope
> that the 26 will answer my prayer(sound promising) The hum (I use AC with
> 50ohm hum pot)did not really border me, but will try to get it
> down......thanks for your inspiration....will report more on sound.
> Viwat
>
=========================================================================
From: Roscoe Primrose <roscoe@aiko.com>
Subject: Re: [JN] 26 pre-amp
Date: Wed, 08 Dec 1999 16:51:49 -0500
Source: Sound Digest Archive v02.n358
Henry Platt wrote:
>
> Hi Viwat,
> I've been messing with the same type of preamp. Mine is all DC and run on
> batteries. two 1.5 volt D cells in series with a voltage trimming pot on the
> filaments and a 12 volt rechargable lead acid battery working into a modular
> DC supply with an output of 130 volts with 12 volts DC in. Im using UTC
> A25s for outputs. 30 ohm resistors from the cathode pins to the positive
> terminal of a nicad cathode battery. Sounds nice. it is one quiet preamp.
> What are you using for cathode bias?
What kind of battery life do you get for the filaments?
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: "Henry Platt" <hnplatt@massed.net>
Subject: Re: [JN] 26 pre-amp
Date: Wed, 08 Dec 1999 20:49:49 -0800
Source: Sound Digest Archive v02.n358
- ----------
>From: David Home <DHome@creo.com>
>To: "'Henry Platt'" <hnplatt@massed.net>, Audio1Nut@aol.com, jim@vt52.com,
sound@deliverator.io.com
>Subject: RE: [JN] 26 pre-amp
>Date: Wed, Dec 8, 1999, 2:04 PM
>
> I will operate the #26 at 150V/6ma/-11V bias into a CCS
> load parellel feeding a UTC A-25 transformer through a 4uF oiler.
Tried it. Liked the sound of a 350 Henry at 6 ma plate choke better, but
really I prefer the A25 by itself, since I'm using VOT's, the Bass down in
the 40's is not really an issue, no need to parallel feed. Sounds more open
in my setup.
Henry
=========================================================================
From: Tom Ronan <tronan@orion.it.luc.edu>
Subject: [JN] 26 preamp, fil ccs boards, etc.
Date: Wed, 02 Jun 1999 20:06:16 -0500
Source: Sound Digest Archive v02.n165
Hello all,
I'm going to sneak in here with a little audio stuff. I hope all of you
arguing people don't mind. *grin*
It's been a long time in the works but I've finally put the 26 preamp
design up on the web. Don't expect much from the website - the schematic
is all there, and all of the parts are showing, but the schematic doesn't
tell half of the wonderful sound available from the little 26 tube. It has
to be built to be believed. (honest)
You can see the preamp at
http:://www.enteract.com/~tronan
and from there go to the 26 preamp page.
I've wanted to release this for a while, but haven't had the time due to
the end of lawschool. Please (!) build one if you have the time. It's
worth the effort!
The real trick, though, is getting the filaments of the direct heated
triodes to be quiet while still sounding good. I've discovered, as have
many on this list, that the DHTs are not as good sounding with DC heating
as they are with AC heating. Unfortunately, with DC heating, the midrange
seems to become rather bleached and the magic is gone. Luckily there is a
fix available, and that fix is a constant current source on the filaments.
This is not a CCS load like Doc B. etc had been talking about, rather
simply a supply for the filaments of the tube.
With the help of John Levreault I was able to get some circuit boards made
for the task. The result is super quiet filaments for preamp tubes. The
boards are very functional for many circumstances - output tubes, driver
tubes, line stage tubes and probably for DHTs in phono stages. They'll
also act as a really nice dc supply for your non-DHT phono stages. The
boards can only really be used for preamp tubes consuming up to 1 ampere of
current, though they can be used for a bit more if you're just using them
for the output or driver stage of an amplifier.
To give a few examples:
the 26 preamp uses one for each tube
a SE 6B4G output stage could use one for each channel, as could a pp output
stage
a SE 300B could use one per channel
a 10 driver tube could use one
a 3A5 DHT preamp could share one between channels, but only if you plan on
tying the cathode Rs together too (right Slagle?)
a SE 205D could use one in the output stage, and maybe as a driver tube.
However, SE2A3s or 211s are unlikely candidates, due to the high current
consumption.
I made a whole bunch of these so I've decided to sell them. Go to the
website above and follow the link to the RonanReg. (John named it, not
me... *grin*) They're quite nicely sized at about 1.4 inches by 5 or so
inches, so they don't take up tons of chassis space.
They're $30 for a pair of the boards, unstuffed, with a full instruction
manual on how to use them in all the kinds of circumstances listed above
and more plus all the info to calculate how to use them for whatever you want.
I've also put some items of vintage audio and pro audio up there. They're
for sale. Looks like I might have stumbled onto a bunch of horns and
drivers, and other theatre contents, so let me know if you're looking for
something I don't have listed on the site.
Some of the links are inactive until I get the time to get them up and
running...
Thanks(!)
Tom
- --------------------------------------------------
Tom Ronan 1045 W. Montana Chicago, IL 60614
Lowther America http://www.lowther-america.com
Oris 150 Horns http://orion.it.luc.edu/~tronan
=========================================================================
From: Tom Ronan <tronan@orion.it.luc.edu> (by way of Tom Ronan <tronan@orion.it.luc.edu>)
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Wed, 02 Jun 1999 22:31:49 -0500
Source: Sound Digest Archive v02.n166
>You can see the preamp at
>
>http:://www.enteract.com/~tronan
>
>and from there go to the 26 preamp page.
Of course, the url is wrong...joelist curse.
it's
http://www.enteract.com/~tronan
Tom
- --------------------------------------------------
Tom Ronan 1045 W. Montana Chicago, IL 60614
Lowther America http://www.lowther-america.com
Oris 150 Horns http://orion.it.luc.edu/~tronan
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Thu, 03 Jun 1999 00:10:02 -0400
Source: Sound Digest Archive v02.n166
Oh, okay...(?) :-)
Tom Ronan (by way of Tom Ronan ) wrote:
>
> >You can see the preamp at
> >
> >http:://www.enteract.com/~tronan
> >
> >and from there go to the 26 preamp page.
>
> Of course, the url is wrong...joelist curse.
>
> it's
>
> http://www.enteract.com/~tronan
- --
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Thu, 3 Jun 1999 13:30:46 +0100 (BST)
Source: Sound Digest Archive v02.n166
Hi Tom,
Your preamp looks good. I confess that I use batteries to power my DHTs
but one of these days will try a current supply.
Your preamp will probably perform even better if you splash out on
transformers rather than cap coupling the output.
Best,
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 Wed, 2 Jun 1999, Tom Ronan wrote:
> Hello all,
>
> I'm going to sneak in here with a little audio stuff. I hope all of you
> arguing people don't mind. *grin*
>
> It's been a long time in the works but I've finally put the 26 preamp
> design up on the web. Don't expect much from the website - the schematic
> is all there, and all of the parts are showing, but the schematic doesn't
> tell half of the wonderful sound available from the little 26 tube. It has
> to be built to be believed. (honest)
>
> You can see the preamp at
>
> http:://www.enteract.com/~tronan
>
> and from there go to the 26 preamp page.
>
> I've wanted to release this for a while, but haven't had the time due to
> the end of lawschool. Please (!) build one if you have the time. It's
> worth the effort!
>
>
> The real trick, though, is getting the filaments of the direct heated
> triodes to be quiet while still sounding good. I've discovered, as have
> many on this list, that the DHTs are not as good sounding with DC heating
> as they are with AC heating. Unfortunately, with DC heating, the midrange
> seems to become rather bleached and the magic is gone. Luckily there is a
> fix available, and that fix is a constant current source on the filaments.
> This is not a CCS load like Doc B. etc had been talking about, rather
> simply a supply for the filaments of the tube.
>
> With the help of John Levreault I was able to get some circuit boards made
> for the task. The result is super quiet filaments for preamp tubes. The
> boards are very functional for many circumstances - output tubes, driver
> tubes, line stage tubes and probably for DHTs in phono stages. They'll
> also act as a really nice dc supply for your non-DHT phono stages. The
> boards can only really be used for preamp tubes consuming up to 1 ampere of
> current, though they can be used for a bit more if you're just using them
> for the output or driver stage of an amplifier.
>
> To give a few examples:
>
> the 26 preamp uses one for each tube
> a SE 6B4G output stage could use one for each channel, as could a pp output
> stage
> a SE 300B could use one per channel
> a 10 driver tube could use one
> a 3A5 DHT preamp could share one between channels, but only if you plan on
> tying the cathode Rs together too (right Slagle?)
> a SE 205D could use one in the output stage, and maybe as a driver tube.
>
> However, SE2A3s or 211s are unlikely candidates, due to the high current
> consumption.
>
> I made a whole bunch of these so I've decided to sell them. Go to the
> website above and follow the link to the RonanReg. (John named it, not
> me... *grin*) They're quite nicely sized at about 1.4 inches by 5 or so
> inches, so they don't take up tons of chassis space.
>
>
> They're $30 for a pair of the boards, unstuffed, with a full instruction
> manual on how to use them in all the kinds of circumstances listed above
> and more plus all the info to calculate how to use them for whatever you want.
>
>
> I've also put some items of vintage audio and pro audio up there. They're
> for sale. Looks like I might have stumbled onto a bunch of horns and
> drivers, and other theatre contents, so let me know if you're looking for
> something I don't have listed on the site.
>
> Some of the links are inactive until I get the time to get them up and
> running...
>
> Thanks(!)
> Tom
>
>
> --------------------------------------------------
> Tom Ronan 1045 W. Montana Chicago, IL 60614
> Lowther America http://www.lowther-america.com
> Oris 150 Horns http://orion.it.luc.edu/~tronan
>
=========================================================================
From: Tom Ronan <tronan@orion.it.luc.edu>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Thu, 03 Jun 1999 09:35:21 -0500
Source: Sound Digest Archive v02.n167
At 01:30 PM 6/3/99 +0100, Simon Busbridge wrote:
>Hi Tom,
>
>Your preamp looks good. I confess that I use batteries to power my DHTs
>but one of these days will try a current supply.
>
>Your preamp will probably perform even better if you splash out on
>transformers rather than cap coupling the output.
>
>Best,
>
>Simon
Simon,
Actually, I've found that the tone of a transformer coupled preamp really
depends upon the tone of the transformer used. Furthermore, with an Rp of 7k
or so, a tranny has to have a lot of inductance to get goof low frequencies out
of the tube. I'm not knocking tranny coupling, but you do not _always_ get
great results. Also a simple R and a good C are much better than you think.
One of the reasons I built this preamp is to remind myself (and everyone else)
that it's easy to get great sound and it doesn't cost a lot of money. It's not
fashionable these days to just do RC coupling, but TONS of great sounding gear
didn't use transformer coupling or CCS loads.
This preamp is not a hifi shocker. It's a beautiful sound which has the
familiarity of classic tube audio, but the new aspect of space and pace of a
direct heated triode. In a line stage it has the tendency to mak the whole
system sound 'direct heated'. One of my first experiences with it was used in
front of S.E.X. amps in comparison to a 300B amp. It made the S.E.X. amps
sound direct heated! Not bad for a few parts, Rs and Cs.
Feel free to make a tranny coupled pre - I'm sure it would sound great. My 26
preamp is RC coupled.
Tom
- ---------------------------------------------------------
Tom Ronan 1045 W. Montana Chicago, IL 60614
Lowther America http://www.lowther-america.com
26 Preamp & Oris 150 Horns http://orion.it.luc.edu/~tronan
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Thu, 3 Jun 1999 15:52:31 +0100 (BST)
Source: Sound Digest Archive v02.n167
Yes, you need a good transformer which is of course expensive. 7 K anode
resistance is I agree near the limit. In the UK we are fortunate enough
to have "super power triodes" (if you can find them) which are similar in
many ways to the type 26 but have a lower anode impedance (2 K or so).
One thing I ought to do soon is to compare a current source like yours to
my battery filament supply. That would be an interesting thing to do.
I do have one question - what about microphonics? This is a small
iritation with my preamp but it's not as bad as it would be with RC
coupling due to the 5:1 output transformers!
I didn't mean to knock your preamp or its coupling which seems like an
excellent project to me.
Best,
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, 3 Jun 1999, Tom Ronan wrote:
> At 01:30 PM 6/3/99 +0100, Simon Busbridge wrote:
> >Hi Tom,
> >
> >Your preamp looks good. I confess that I use batteries to power my DHTs
> >but one of these days will try a current supply.
> >
> >Your preamp will probably perform even better if you splash out on
> >transformers rather than cap coupling the output.
> >
> >Best,
> >
> >Simon
>
> Simon,
>
> Actually, I've found that the tone of a transformer coupled preamp really
> depends upon the tone of the transformer used. Furthermore, with an Rp of 7k
> or so, a tranny has to have a lot of inductance to get goof low frequencies out
> of the tube. I'm not knocking tranny coupling, but you do not _always_ get
> great results. Also a simple R and a good C are much better than you think.
>
>
> One of the reasons I built this preamp is to remind myself (and everyone else)
> that it's easy to get great sound and it doesn't cost a lot of money. It's not
> fashionable these days to just do RC coupling, but TONS of great sounding gear
> didn't use transformer coupling or CCS loads.
>
> This preamp is not a hifi shocker. It's a beautiful sound which has the
> familiarity of classic tube audio, but the new aspect of space and pace of a
> direct heated triode. In a line stage it has the tendency to mak the whole
> system sound 'direct heated'. One of my first experiences with it was used in
> front of S.E.X. amps in comparison to a 300B amp. It made the S.E.X. amps
> sound direct heated! Not bad for a few parts, Rs and Cs.
>
> Feel free to make a tranny coupled pre - I'm sure it would sound great. My 26
> preamp is RC coupled.
>
> Tom
> ---------------------------------------------------------
> Tom Ronan 1045 W. Montana Chicago, IL 60614
> Lowther America http://www.lowther-america.com
> 26 Preamp & Oris 150 Horns http://orion.it.luc.edu/~tronan
>
=========================================================================
From: Torsten.Loesch@enhar-ha.nthames.nhs.uk
Subject: Re(2): [JN] 26 preamp, fil ccs boards, etc.
Date: 03 Jun 1999 17:17:30 +0100
Source: Sound Digest Archive v02.n167
Hi there,
> Yes, you need a good transformer which is of course expensive. 7 K anode
> resistance is I agree near the limit. In the UK we are fortunate enough
> to have "super power triodes" (if you can find them) which are similar in
> many ways to the type 26 but have a lower anode impedance (2 K or so).
Which ones are these? And who carries them?
Later Thorsten
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: Re(2): [JN] 26 preamp, fil ccs boards, etc.
Date: Thu, 3 Jun 1999 17:29:35 +0100 (BST)
Source: Sound Digest Archive v02.n167
PM202 etc., 2V types. Hard to find nowadays.
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 3 Jun 1999 Torsten.Loesch@enhar-ha.nthames.nhs.uk wrote:
> Hi there,
>
> > Yes, you need a good transformer which is of course expensive. 7 K anode
> > resistance is I agree near the limit. In the UK we are fortunate enough
> > to have "super power triodes" (if you can find them) which are similar in
> > many ways to the type 26 but have a lower anode impedance (2 K or so).
>
> Which ones are these? And who carries them?
>
> Later Thorsten
>
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Thu, 03 Jun 1999 19:10:24 +0200
Source: Sound Digest Archive v02.n167
Simon Busbridge wrote:
> In the UK we are fortunate enough
> to have "super power triodes" (if you can find them) which are similar in
> many ways to the type 26 but have a lower anode impedance (2 K or so).
What kind of triodes are you talking about -- WE 437 or the even harder to find
EC8020 where transconductance S (mA/V) and mu have almost the same value?
If I remember correctly: Ri = S / mu. EC8020 has S=60 mA/V and mu=55, Ri=1.09 kOhm.
WE437: S=approx 42, mu=41, Ri=1.02 kOhm).
Christian
=========================================================================
From: "Bart Shepherd" <bart.shepherd@ttmsolutions.com>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Fri, 4 Jun 1999 02:29:39 +1000
Source: Sound Digest Archive v02.n167
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
snip
In the UK we are fortunate enough
> to have "super power triodes" (if you can find them) which are similar in
> many ways to the type 26 but have a lower anode impedance (2 K or so).
snip
Hi Simon,
Many thanks you your recent advice.
Would you mind sharing with us the identity and characteristics of these
"super power triodes", they sound most interesting.
Thanks,
Bart
=========================================================================
From: "Bart Shepherd" <bart.shepherd@ttmsolutions.com>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Fri, 4 Jun 1999 02:38:03 +1000
Source: Sound Digest Archive v02.n167
From Tom Ronan:
snip
> One of the reasons I built this preamp is to remind myself (and everyone
else)
> that it's easy to get great sound and it doesn't cost a lot of money.
It's not
> fashionable these days to just do RC coupling, but TONS of great sounding
gear
> didn't use transformer coupling or CCS loads.
snip
A very excellent point!
We tend to too often get caught up in the theory of "guilding the lily" and
in doing so add layers of complexity and expense which brings with it its
own new side effects.
Simplicity and minimum parts count, well executed, can be very hard to beat
for a musical result.
Well done and said Tom!
Bart
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Fri, 4 Jun 1999 08:16:01 +0100 (BST)
Source: Sound Digest Archive v02.n168
No, they are much older than that, popular in the 1930's when sets were
battery powered. The g tends to be quite low, maybe around 5, but they
are DH and the anode resistance was deliberately made low so that they
could act as output valves. They are also generally very linear. I
have tried the PM202 (Mullard), P220A (Mazda) and P2 (Mazda), but the P2
has a higher ra. I have old Cossor and Mazda catalogues from the 30's
which I can dig out if anyone is interested.
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, 3 Jun 1999, Christian Rintelen wrote:
> Simon Busbridge wrote:
>
> > In the UK we are fortunate enough
> > to have "super power triodes" (if you can find them) which are similar in
> > many ways to the type 26 but have a lower anode impedance (2 K or so).
>
> What kind of triodes are you talking about -- WE 437 or the even harder to find
> EC8020 where transconductance S (mA/V) and mu have almost the same value?
>
> If I remember correctly: Ri = S / mu. EC8020 has S=60 mA/V and mu=55, Ri=1.09 kOhm.
> WE437: S=approx 42, mu=41, Ri=1.02 kOhm).
>
> Christian
>
>
=========================================================================
From: "=?ISO-8859-1?Q?Torbj=F8rn_Lien?=" <mdrivekl@online.no>
Subject: Re: [JN] 26 preamp, fil ccs boards, etc.
Date: Fri, 4 Jun 1999 12:12:31 +0200
Source: Sound Digest Archive v02.n168
Simon Busbridge wrote:
>
> No, they are much older than that, popular in the 1930's
> when sets were battery powered. The g tends to be quite
> low, maybe around 5, but they are DH and the anode resistance
> was deliberately made low so that they could act as output
> valves. They are also generally very linear. [snip]
Thats certainly true. I had for a while a line amp running
with the LP2. The only type I've listened too so far, but it
made me completely change my wievs of what a line amp should be.
I've measured and written out characteristics one some more
types,-in the search for an appropriate *vintage and origin*
(Uhm,-and musically!) matching input-driver stage for the PX25.
It seems that the generously sized inner structures, combined
with the fact that these tubes don't do that much, makes for
truly excellent linearity.
I believe these types were mainly develloped and manufactured
to be used in driving telephone lines.
Anyway, here's a little list over some beautifil early types.
Like any anxient/obsolete tube-types of European origin,
I guess the profit-greedy, vacuum-cleaning individuals are
already making a market for these in the far east,-
Soo,- better stock up before it's too late!
. TYPE fil.(V-A) Ug:-V Ia:mA Gm:mA/V µ Rp:Kohms
. HL2K 2/0,15 3,0 1,8 1,50 27 18,0
. KC3 2/0,22 2,8 3,0 2,50 25 10,0
. LP2 2/0,20 - 5,2 3,85 15 3,9
. 220P 2/0,20 7,5 11,0 2,25 9 4,0
. PM202 2/0,20 12,0 14,0 3,5 7 2,0
. LS8A 4/0,15 8,0 26,0 3,0 6 2,0
. 3A/109B 4/0,25 6 2,0
. 3A/109A 4/0,25 6 2,0
. LS7 4/0,15 4,0 21,0 2,4 12 5,0
. 3A/110A 4/0,25 12 5,5
. 3A/107A 4/0,25 7 5,5
. 3A/107B 4/0,25 7 5,5
;)Happy hunting,
Torbjoern ,Norway
>
>
>
>
=========================================================================
From: David Home <DHome@creo.com>
Subject: [JN] #26 preamp report
Date: Sun, 2 Jan 2000 00:11:21 -0800
Source: Sound Digest Archive v02.n381
Hello all. I hope that all the members of this list have had a good Holliday
season.
I am writing to pass on my experiences over the last two weeks getting my
#26 line level amp going and tweaked to the point of satisfaction.
Right off the bat, I want to thank Tom Ronan for his help in finalizing the
filament heating without which the tube would just have had an unbearable
level of hum. I ended up heating the #26s off of a common supply and used a
shared cathode resistor and bypass cap as well. My two nicer #26s biased to
within 0.2ma of each other with a common supply, so I think this works well
and allows the use of a single good BG bypass rather then two lesser types
for a cash challenged builder like me! The heater starts with a 6.3V/2.4A
winding feeding Schottky 35V/9A diodes into a full wave bridge. Then a
15KuF/25V cap, a filament choke of unknown value ( 60mH would be my guess)
then another 15KuF cap. This supplies 6.6V to a LT1083ADJ regulator
operating as a conventional voltage regulator. The regulator supplies 4.4V
to another LT1083ADJ operating as a CCS. This supplies the required 2.1A DC
to the parallel #26 filaments at a resultant voltage of 1.54V. This method
of regulation is very good and simpler then other regulation methods I was
considering. I can't find any ripple at the lowest level of my scope ( uV)
or my meter.
I am lucky to have two UTC A-25 line output transformers which I very much
wanted to use with the #26s. They are 15K:500/250/125/50 ohm type and
designed for a DC current up to 8ma on the primary. I had two possible ways
to use them though, conventional SE operation between the tube and the B+ or
parallel feed. I recently built VV32 amps using parallel feed, and am quite
taken with it right now so I built this way first. I used a CCS on the tube
set at 6ma, and parallel fed the A-25 through a 4uF oiler. I ended up with
180V on the tube plates which I found to be better sounding then lower
voltages. Now the sound was very very good having the famed detail of
parallel feed, a dead black hum free background and stunningly clear high
treble. But... it also had a certain lifeless sterile quality that I
sometimes have gotten for the use of CCS loading. Dynamics are rather flat
and while the bass goes very low it lacked any range of colour. An
interesting thing was that these shortcoming almost completely went away
when the pre-amp was cranked almost wide open. I wonder if using an air
gapped transformer without any DC might mean there is a certain threshold
that needs to be pushed through. The A-25 was never designed for what I was
using it for, but if this a possible area of concern I am just guessing. I
tried to transformer with and without loading of the secondary as well and
ended up using 1K on the 250 ohm taps along with the interconnect. A lot
less ringing and removed an edgy quality from violins but also dulled piano
attacks a bit.
So then I converted it to conventional SE operation with 175V/6ma/-13V being
the nice sounding operating point. Sound is very conventional SE with warmth
in spades and a smooth coherent sound. Less presence and detail though as
well. Bass a bit flabby but more alive. Tom Ronan advised me that the size
of the bypass cap on this tube has a BIG effect on bass weight and I can
second that whole heartedly. I have a 1K CC resistor and have bypassed it
first with a 100uF/25V Nichicon Muse which was too lean. Then a 470 Muse
when in and it is too blotted now. So I think 220uF will be just right for
my system.
In conclusion, this is the best sounding pre-amp tube I have used hands
down. An exact description escapes me, but the sound is the polar opposite
of the 417A/7119 type of sound and worth looking into if the complex heating
does not turn you off. Tom sells a board for a regulator by the way. Sound
is very organic and seductive, no surprise for a DHT I guess!
I still think parallel feed will work nicely with this tube but with proper
transformers designed for this purpose. I will explore this soon. I am
thinking of getting a pair of permalloy 15K:600 transformers from Magnaquest
and using the A-25s as a choke load. Anyone who might have traveled this
road, using the parellel feed line amp iron that is, I would appreciate
hearing of your experiences.
As usual, all comments and questions welcome. Regards, David
=========================================================================
From: MHuber@t-online.de (Manfred Huber)
Subject: Re: [JN] #26 preamp report
Date: Sun, 02 Jan 2000 11:09:55 +0100
Source: Sound Digest Archive v02.n381
David,
>Tom Ronan advised me that the size of the bypass cap on this tube has
>a BIG effect on bass weight and I can second that whole heartedly.
May I suggest you try fixed bias with a series battery in the grid circuit.
In >-+ |
| (+) (-) plate
pot -+- battery -+---- grid
| +--5M6------+ cathode
| +--220nF----+ |
| |
| |
GND--+-----------------------+-------------...
A single V23GA battery (used in Photo equipment, 10.3mm x 28.5mm) gets you -12V of bias voltage .
Or use a V74PX for -15V of bias voltage.
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: [JN] #26 preamp report
Date: Sat, 8 Jan 2000 15:29:58 -0800
Source: Sound Digest Archive v02.n392
Hi Manfred and Joes. Ok so I converted my #26 pre-amp to the type of battery
bias you suggested three days ago. The suggestion was to remove to cathode
RC biasing and put a cell in the grid circuit. My amp is IT coupled and CCS
heated, and previously used a shared 1K resistor and 470uF Nichison Muse
capacitor for bias. I opted for the 15V battery and this was a mistake. The
#26 is rated at 180V max on the plate and with that voltage and -15V bias I
only got 4ma of current. I am running now with 190V (yikes!) on the plates
to give a 5ma current which is as low in current as I wish to go. I may
replace the cells with the 12V type to get the current up to 6.5ma at ~160
or so. But read on.
OK so the good news first. Within three seconds of the first track my jaw
dropped and I sat there in disbelief. The detail and transparency is like
nothing I have heard from my system before! And the bass is absolutely right
on! Deep but still very tuneful. I could hear the bass violin player bending
the deep bass notes subtlety which I had not heard before on this record.
All this just by removing a f___ing bypass cap from the signal path???!!!
Now I know it is not a great cap these Muses but still...
And there is always bad news too right? So there is an edge now to leading
attack of notes, a harshness of sorts, that sounds almost like some kind of
distortion. It is quite irritating and worse with the CD player then with
the phono. I checked the pre-amp on the scope and have a very nice 1K square
wave with some ringing at 225KHz. It decays quickly with the 2.2K load I
have on the output of the 15K:600 transformer. No alarm bells from the look
of the scope display. Increasing the loading did not affect the sonic
character or the scope trace. And anyway the pre-amp did not have this sound
before I changed the biasing.
So Manfred, could it be something to do with the battery biasing method or
the type of battery itself? The Varne cells I got are alkaline.
Now the cells fresh out of the box are 15.4V. Maybe the cells are too new
and need to break in? Or I should hook the cells up to a power resistor and
burn the voltage down a volt?
I have not had this problem with battery biasing by NiCds in the cathode
circuit. As a last resort I could build a stack of 11 NiCds for a bias of
13.2V and stick it on the cathode. Considering what these friggin 15V cells
cost I would like to make them work. Any suggestions appreciated.
David Home
Plate Qualification Specialist
Creo Products Inc.,
4225 Kincaid Street,
Burnaby, British Columbia,
Canada, V5G 4P5
Tel. 604.451.2720 Ex. 2397
Fax. 604.437.9891
Email: dhome@creo.com
Website:www.creo.com
-----Original Message-----
From: MHuber@t-online.de [mailto:MHuber@t-online.de]
Sent: Sunday, January 02, 2000 2:10 AM
To: JoeNet
Subject: Re: [JN] #26 preamp report
David,
>Tom Ronan advised me that the size of the bypass cap on this tube has
>a BIG effect on bass weight and I can second that whole heartedly.
May I suggest you try fixed bias with a series battery in the grid circuit.
In >-+ |
| (+) (-) plate
pot -+- battery -+---- grid
| +--5M6------+ cathode
| +--220nF----+ |
| |
| |
GND--+-----------------------+-------------...
A single V23GA battery (used in Photo equipment, 10.3mm x 28.5mm) gets you
- -12V of bias voltage .
Or use a V74PX for -15V of bias voltage.
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: MHuber@t-online.de (Manfred Huber)
Subject: RE: [JN] #26 preamp report
Date: Sun, 09 Jan 2000 17:01:35 +0100
Source: Sound Digest Archive v02.n393
David,
>I may replace the cells with the 12V type to get the current up to 6.5ma at ~160
>or so.
This is the first thing I would try. IMHO, to be able to hear the effect of the
biasing method alone you need to maintain the same operating point.
>All this just by removing a f___ing bypass cap from the signal path???!!!
>Now I know it is not a great cap these Muses but still...
A single cap can have a great influence, especially if it's an electrolyte cap.
But, as I said above you changed more than this...
>So there is an edge now to leading attack of notes, a harshness of sorts,
>that sounds almost like some kind of distortion.
I did not experience this effect. There may be some reasons for this.
First, do you use a grid stopper resistor or ferrite bead? If not, you should try it.
One down side of the series battery that I have experienced is that the stage
tends to get more susceptible for HF pickup.
Try some different caps across the battery and see if it makes a difference.
You may also want to try no cap at all.
I also have to say that I have never tried the series battery biasing with
this kind of battery. The max biasing voltage I have used until today is 6V from
two Li cells.
>Or I should hook the cells up to a power resistor and burn the voltage down a volt?
You can do this but be aware that the cells will be almost empty after discharging
them to 12V. This also means that their impedance will rise.
How did you contact the battery? If you are good with the soldering iron you can
try to solder directly to the poles of the battery. Use a piece of sand paper on
the poles first and then apply some tin with a *hot* soldering iron.
Try to minimize the soldering time to the absolute minimum. Stick the heated pole
into cold water immediately after soldering. Sounds complicated, but I have done
this for several times without problems. All you have to loose is a battery...
A simpler method may be to use one of these modern electrically conducting
glues but I have never tried this.
>I have not had this problem with battery biasing by NiCds in the cathode
>circuit. As a last resort I could build a stack of 11 NiCds for a bias of
>13.2V and stick it on the cathode. Considering what these friggin 15V cells
>cost I would like to make them work. Any suggestions appreciated.
Remember that a stack of 11 cells has eleven times the impedance of a single cell.
This has kept me from trying cathode battery biasing when bias voltages of
more then 3V are needed.
Please keep us posted on your results.
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: [JN] #26 preamp report
Date: Sun, 9 Jan 2000 22:17:53 -0800
Source: Sound Digest Archive v02.n393
Hi Manfred and Joes. I didn't get to do much on the weekend but I did try
removing the 220N oil caps I had across the batteries. I would say that the
sound got slightly more relaxed but at the expense of transparency. The
affect was very subtle and I still sat listening with my teeth clenched. My
batteries are in nice 2/3AA battery holders that have good nickel plated
contacts under good pressure. My thinking is that I have put a part directly
in the signal path and it is not a good sounding part! As you have not tried
batteries of this voltage level as well, possibly the cell itself sounds
bad. It must have 10 tiny discrete cells internally all stacked up. I will
play around with a few other variables but am reluctant to buy the 12V cells
if they possess the family sound. 8^)
I am in complete agreement about the grid stopper suggestion. Thanks for
that and I will try this first.
Your comment about the impedance adding when stacking 10 NiCds made we think
that the impedance of the 15V alkaline is also the accumulation of 10
discrete cells. Is this a possible concern?
Regards,
David Home
Plate Qualification Specialist
Creo Products Inc.,
4225 Kincaid Street,
Burnaby, British Columbia,
Canada, V5G 4P5
Tel. 604.451.2720 Ex. 2397
Fax. 604.437.9891
Email: dhome@creo.com
Website:www.creo.com
-----Original Message-----
From: MHuber@t-online.de [mailto:MHuber@t-online.de]
Sent: Sunday, January 09, 2000 8:02 AM
To: JoeNet
Subject: RE: [JN] #26 preamp report
David,
>I may replace the cells with the 12V type to get the current up to 6.5ma at
~160
>or so.
This is the first thing I would try. IMHO, to be able to hear the effect of
the
biasing method alone you need to maintain the same operating point.
>All this just by removing a f___ing bypass cap from the signal path???!!!
>Now I know it is not a great cap these Muses but still...
A single cap can have a great influence, especially if it's an electrolyte
cap.
But, as I said above you changed more than this...
>So there is an edge now to leading attack of notes, a harshness of sorts,
>that sounds almost like some kind of distortion.
I did not experience this effect. There may be some reasons for this.
First, do you use a grid stopper resistor or ferrite bead? If not, you
should try it.
One down side of the series battery that I have experienced is that the
stage
tends to get more susceptible for HF pickup.
Try some different caps across the battery and see if it makes a difference.
You may also want to try no cap at all.
I also have to say that I have never tried the series battery biasing with
this kind of battery. The max biasing voltage I have used until today is 6V
from
two Li cells.
>Or I should hook the cells up to a power resistor and burn the voltage down
a volt?
You can do this but be aware that the cells will be almost empty after
discharging
them to 12V. This also means that their impedance will rise.
How did you contact the battery? If you are good with the soldering iron you
can
try to solder directly to the poles of the battery. Use a piece of sand
paper on
the poles first and then apply some tin with a *hot* soldering iron.
Try to minimize the soldering time to the absolute minimum. Stick the heated
pole
into cold water immediately after soldering. Sounds complicated, but I have
done
this for several times without problems. All you have to loose is a
battery...
A simpler method may be to use one of these modern electrically conducting
glues but I have never tried this.
>I have not had this problem with battery biasing by NiCds in the cathode
>circuit. As a last resort I could build a stack of 11 NiCds for a bias of
>13.2V and stick it on the cathode. Considering what these friggin 15V cells
>cost I would like to make them work. Any suggestions appreciated.
Remember that a stack of 11 cells has eleven times the impedance of a single
cell.
This has kept me from trying cathode battery biasing when bias voltages of
more then 3V are needed.
Please keep us posted on your results.
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: MHuber@t-online.de (Manfred Huber)
Subject: RE: [JN] #26 preamp report
Date: Mon, 10 Jan 2000 08:41:16 +0100
Source: Sound Digest Archive v02.n394
David,
>It must have 10 tiny discrete cells internally all stacked up. I will
>play around with a few other variables but am reluctant to buy the 12V cells
>if they possess the family sound. 8^)
You will not know before you have tried it. I think that it is very well possible
that you will not like the sound of the 12V cell. But remember that there are some
qualities to the sound of the series battery that you liked very much when first
listening to it. It may be worth the time to make a few more experiments and see if
you can not have it all.
>Your comment about the impedance adding when stacking 10 NiCds made we think
>that the impedance of the 15V alkaline is also the accumulation of 10
>discrete cells. Is this a possible concern?
I think it is of more concern than with the series battery. In both cases we have
a stack of cells but the series battery operates on a very high impedance node
(grid) while the cathode battery operates on a low impedance node.
To set thinks straight: I have no problem at all if you come to the conclusion that
you don't like the sound of the series battery. It was suggested by me as an
experiment that is easy to try. I think it is great that you have actually tried it
and share your findings with us!
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: [JN] #26 preamp report
Date: Mon, 10 Jan 2000 09:44:48 -0800
Source: Sound Digest Archive v02.n394
Hi Manfred and Joes. I understand your point about the battery sound which I
did find very admirable qualities in. I do not intend to give up and am
happy to try things out and discard them if they are not positive. We learn
as much if not more from the experiments that fail! 8^)
My reluctance to not get the 12V alkaline cells has more to do with the cell
type than the voltage. As you have had good results with Lithium up to 6V,
four cells would give me 12V for the same cost as the 12V alkaline. Maybe
Alkaline cells are just not HiFi. Am I over concerned about the nature of
the cell type in your opinion?
I will try the grid stopper resistors tonight and report back.
Regards, David Home
- -----Original Message-----
From: MHuber@t-online.de [mailto:MHuber@t-online.de]
Sent: Sunday, January 09, 2000 11:41 PM
To: JoeNet
Subject: RE: [JN] #26 preamp report
David,
>It must have 10 tiny discrete cells internally all stacked up. I will
>play around with a few other variables but am reluctant to buy the 12V
cells
>if they possess the family sound. 8^)
You will not know before you have tried it. I think that it is very well
possible
that you will not like the sound of the 12V cell. But remember that there
are some
qualities to the sound of the series battery that you liked very much when
first
listening to it. It may be worth the time to make a few more experiments and
see if
you can not have it all.
>Your comment about the impedance adding when stacking 10 NiCds made we
think
>that the impedance of the 15V alkaline is also the accumulation of 10
>discrete cells. Is this a possible concern?
I think it is of more concern than with the series battery. In both cases we
have
a stack of cells but the series battery operates on a very high impedance
node
(grid) while the cathode battery operates on a low impedance node.
To set thinks straight: I have no problem at all if you come to the
conclusion that
you don't like the sound of the series battery. It was suggested by me as an
experiment that is easy to try. I think it is great that you have actually
tried it
and share your findings with us!
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: [JN] #26 preamp report
Date: Mon, 10 Jan 2000 09:56:14 -0800
Source: Sound Digest Archive v02.n394
Hi Grover. I understand your point about the sound of battery biasing, but I
did not get the edgy effect when I converted the biasing in my phono section
417a and 7308 to single cell NiCd in the cathode. So I think the technique
has potential that is worth exploring. What I wish to know is weather the
problem is the type of battery biasing, the type of battery itself, the high
voltage needed or the specific use with the #26 and the IT coupling.
I remember the huge improvement in an earlier PP project using 6BX7s when I
went from fixed bias to cathode bias. I can always just buy some Black Gate
bypass caps and go back to RC cathode biasing for the #26. I know that will
sound smooth.
Regards, David
- -----Original Message-----
From: Grover Gardner [mailto:groverg@postoffice.att.net]
Sent: Monday, January 10, 2000 7:23 AM
To: David Home; 'Manfred Huber'; JoeNet
Subject: RE: [JN] #26 preamp report
At 10:17 PM -0800 1/9/00, David Home wrote:
>Hi Manfred and Joes. I didn't get to do much on the weekend but I did try
>removing the 220N oil caps I had across the batteries. I would say that the
>sound got slightly more relaxed but at the expense of transparency. The
>affect was very subtle and I still sat listening with my teeth clenched. My
>batteries are in nice 2/3AA battery holders that have good nickel plated
>contacts under good pressure. My thinking is that I have put a part
directly
>in the signal path and it is not a good sounding part! As you have not
tried
>batteries of this voltage level as well, possibly the cell itself sounds
>bad. It must have 10 tiny discrete cells internally all stacked up. I will
>play around with a few other variables but am reluctant to buy the 12V
cells
>if they possess the family sound. 8^)
>I am in complete agreement about the grid stopper suggestion. Thanks for
>that and I will try this first.
>Your comment about the impedance adding when stacking 10 NiCds made we
think
>that the impedance of the 15V alkaline is also the accumulation of 10
>discrete cells. Is this a possible concern?
At the risk of ruffling a lot of feathers, the "edge" you complain of
is always what I have heard with battery biasing. For this reason I
have avoided it, but it's entriely possible that it can be
ameliorated by tweaks and better implementation...
The use of a small carbon grid-stopper seemed like a good suggestion to me.
- -------
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: RE: [JN] #26 preamp report
Date: Mon, 10 Jan 2000 10:23:09 -0500
Source: Sound Digest Archive v02.n394
At 10:17 PM -0800 1/9/00, David Home wrote:
>Hi Manfred and Joes. I didn't get to do much on the weekend but I did try
>removing the 220N oil caps I had across the batteries. I would say that the
>sound got slightly more relaxed but at the expense of transparency. The
>affect was very subtle and I still sat listening with my teeth clenched. My
>batteries are in nice 2/3AA battery holders that have good nickel plated
>contacts under good pressure. My thinking is that I have put a part directly
>in the signal path and it is not a good sounding part! As you have not tried
>batteries of this voltage level as well, possibly the cell itself sounds
>bad. It must have 10 tiny discrete cells internally all stacked up. I will
>play around with a few other variables but am reluctant to buy the 12V cells
>if they possess the family sound. 8^)
>I am in complete agreement about the grid stopper suggestion. Thanks for
>that and I will try this first.
>Your comment about the impedance adding when stacking 10 NiCds made we think
>that the impedance of the 15V alkaline is also the accumulation of 10
>discrete cells. Is this a possible concern?
At the risk of ruffling a lot of feathers, the "edge" you complain of
is always what I have heard with battery biasing. For this reason I
have avoided it, but it's entriely possible that it can be
ameliorated by tweaks and better implementation...
The use of a small carbon grid-stopper seemed like a good suggestion to me.
- -------
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: "Fred Volz" <fcv@emotiveaudio.com>
Subject: Re: [JN] #26 preamp report
Date: Mon, 10 Jan 2000 17:03:46 -0500
Source: Sound Digest Archive v02.n395
Grover Gardner said:
>At the risk of ruffling a lot of feathers, the "edge" you complain of
>is always what I have heard with battery biasing. For this reason I
>have avoided it, but it's entriely possible that it can be
>ameliorated by tweaks and better implementation...
I would agree with this. The application for which we tried this was a bit
different (cathode of 5687 using NiCads), but we didn't like it as well as
LEDs. The battery was, however, better overall than a resistor, but with
some tradeoffs. Resistors sound very smooth, but a bit muddled or hazy. And,
the problem of a bypass cap is truly a nightmare: each option sounds
terrible in its own way. So, we ended up using LEDs as the compromise with
the least annoying qualities.
>
>The use of a small carbon grid-stopper seemed like a good suggestion to me.
I was at first suspicious of adding anything in the signal path. But, for
us, use of a small grid stopper doesn't hurt the sound--it actually improves
the sound quite a bit.
>
>
>-------
>Grover Gardner
>groverg@postoffice.att.net
Fred Volz
fcv@emotiveaudio.com
=========================================================================
From: David Home <DHome@creo.com>
Subject: RE: [JN] #26 preamp report
Date: Tue, 11 Jan 2000 10:21:34 -0800
Source: Sound Digest Archive v02.n396
Hello Manfred and Joes. OK so I had time to try a few things last night.
Firstly, with some use on them now, the voltage of the cells has fallen from
15.4V to 15.15V. I forget to listen to this first before installing the gris
stoppers.
Then I installed 33 ohm grid stoppers. BIG improvement. The edge was gone.
Surprise, surprise.
Put the battery bypass cap back in, this time using a 0.1uF/400V MIT instead
of the 0.22/400V oiler. Slightly smoother highs but the change was on the
order where the power of suggestion could be kicking in.
So I am going to leave it as it is for a while. I have some freindly audio
guys coming over this weekend so I will see what they think. Was the
improvement the result of the cells breaking in? This is what I wonder.
Regards, David
- -----Original Message-----
From: MHuber@t-online.de [mailto:MHuber@t-online.de]
Sent: Sunday, January 09, 2000 11:41 PM
To: JoeNet
Subject: RE: [JN] #26 preamp report
David,
>It must have 10 tiny discrete cells internally all stacked up. I will
>play around with a few other variables but am reluctant to buy the 12V
cells
>if they possess the family sound. 8^)
You will not know before you have tried it. I think that it is very well
possible
that you will not like the sound of the 12V cell. But remember that there
are some
qualities to the sound of the series battery that you liked very much when
first
listening to it. It may be worth the time to make a few more experiments and
see if
you can not have it all.
>Your comment about the impedance adding when stacking 10 NiCds made we
think
>that the impedance of the 15V alkaline is also the accumulation of 10
>discrete cells. Is this a possible concern?
I think it is of more concern than with the series battery. In both cases we
have
a stack of cells but the series battery operates on a very high impedance
node
(grid) while the cathode battery operates on a low impedance node.
To set thinks straight: I have no problem at all if you come to the
conclusion that
you don't like the sound of the series battery. It was suggested by me as an
experiment that is easy to try. I think it is great that you have actually
tried it
and share your findings with us!
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: MHuber@t-online.de (Manfred Huber)
Subject: RE: [JN] #26 preamp report
Date: Wed, 12 Jan 2000 08:45:20 +0100
Source: Sound Digest Archive v02.n397
Hello David,
>Then I installed 33 ohm grid stoppers. BIG improvement. The edge was gone.
>Surprise, surprise.
This is great news.
>Put the battery bypass cap back in, this time using a 0.1uF/400V MIT instead
>of the 0.22/400V oiler. Slightly smoother highs but the change was on the
>order where the power of suggestion could be kicking in.
I have to admit that I have never tried it without the bypass. Time for some
experimentation on my side I guess.
>So I am going to leave it as it is for a while. I have some freindly audio
>guys coming over this weekend so I will see what they think.
Please tell us about it.
>Was the improvement the result of the cells breaking in? This is what I wonder.
You will know after you have heated your iron and taken out the grid stopper <g>
Regards
Manfred
- ------------------
Manfred Huber
MHuber@t-online.de
- ------------------
=========================================================================
From: David Home <DHome@creo.com>
Subject: [JN] #26 preamp update
Date: Sat, 15 Jan 2000 00:28:46 -0800
Source: Sound Digest Archive v02.n404
Hello Manfred and joes.
OK so I gave the battery grid bias everything I had, but I've pulled it out.
After a couple of days, I decided the edge was still there and I wanted it
gone.
I removed the grid stoppers and there was really little if any change, and
then I removed the bypass cap and it did not really make any difference
either. I know that to compete the experiment I should have tried the 12V
cells, so forgive me. So now I am back to good old RC biasing and while I
miss the hyper detail, I REALLY like the smoothness. If I come into some
cheap lithium cells, I will try the 12V bias point ( which is the same as I
run with RC biasing ) and report my findings. Thanks to all who made
suggestions and expressed their opinions to a fellow builder.
Regards, David
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] 26 pre - Magic
Date: Tue, 25 Jan 2000 23:17:24 EST
Source: Sound Digest Archive v02.n418
In a message dated 1/25/00 7:42:12 PM US Mountain Standard Time,
carter@i1.net writes:
> magic is hard to give up.
Greets Jeets Neets,
Yup, but just a little every once in a while is enough to keep me trying for
more.
Each little spell adds just enough to make this Mystery Tour rewarding.
It is true. The good folks who are investing in NOS tubes may be missing
something in their spreadsheets.
It is so fine to hear something fresh and true in a piece of music I have
memorized. Only magic can account for it.
How much magic? Ha ha ha ha ha ha
Enough.
Happy Ears!
Al B^}
=========================================================================
From: "St. Cinnamon" <ram@ispnook.com>
Subject: Re: [JN] 26 pre (Steve)
Date: Sun, 23 Jan 2000 21:19:30 -0500
Source: Sound Digest Archive v02.n415
Steve,
Yes, it is Jim DeKort's design, I am using Tom Ronan's filament boards
and a separate power supply. With this combination I do not have any hum
problems. The pre also has Electra-print plate load chokes, which are
terrific.
This is a great sounding tube, very musical (not hi-fi), well worth giving
it a try especially if you already have the tubes.
You can first try the circuit with a plate load resistor to see if you like
it. Jim DeKort was very helpful with any questions I had, as was Tom Ronan.
Give it a go there are alot of unselfish people in this hobby who would
help you out if needed.
Thanks,
Ritchie
- ----- Original Message -----
From: Brooks, Steve <Steve.Brooks@turner.com>
To: 'St. Cinnamon' <ram@ispnook.com>
Sent: Friday, January 21, 2000 9:44 AM
Subject: RE: [JN] dact stepped attenuator
> Ritchie,
> Is that Jim DeKort's design that you built? I have some 26's and
have been eyeing that
> preamp, but I'm a novice at building and am a little concerned
about trying a preamp..
> especially with a tube known for hum.
> Steve
>
> -----Original Message-----
> From: St. Cinnamon [mailto:ram@ispnook.com]
> Sent: Thursday, January 20, 2000 10:40 PM
> To: sound@deliverator.io.com
> Subject: [JN] dact stepped attenuator
>
>
> I am looking for some feedback on the Danish audio connect (dact) stepped
attenuators. I'm presently using a noble pot in a choke loaded 26 pre. If
anyone is presently using or has had experience with the dact, could you
please pass on your findings.
> thanks,
> Ritchie
>
>
>
=========================================================================
From: TubeGarden@aol.com
Subject: Re: [JN] 26 pre (Steve)
Date: Mon, 24 Jan 2000 00:02:38 EST
Source: Sound Digest Archive v02.n415
In a message dated 1/23/00 7:18:50 PM US Mountain Standard Time,
ram@ispnook.com writes:
> a tube known for hum
Greets Jeets Neets,
I think there is too much nasty gossip in this rather insecure hobby of ours.
Too many slights and cheap shots and not enough really heart felt insults.
Let us not spread rumors without having built and tuned and rebuilt circuits
involving the unit under attack.
Some people are known to use their facile nasty tongue to try and avoid doing
any worthwhile work. Just smile and nod and try it for yourself if you are
interested.
Remember, there are very few technical problems which cannot be overcome with
talent, imagination, hard work and lots of money :)
If all of the above fail, please share your frustration so we do not waste
time replicating your failures.
But, make your comments meaningfully malicious and wound the garbage mortally.
"Known for hum" is pretty weak stuff.
Happy Ears!
Al B^}
=========================================================================
From: Chris Beck <n9zes@execpc.com>
Subject: Re: [JN] 26 pre (Steve)
Date: Mon, 24 Jan 2000 07:07:44 -0600
Source: Sound Digest Archive v02.n415
Well put, Al. I've been guilty of that myself. Gotta try it before you bash it.
However, there are definite rules in audio that there is consensus about - tubes
rule!
Chris
TubeGarden@aol.com wrote:
> In a message dated 1/23/00 7:18:50 PM US Mountain Standard Time,
> ram@ispnook.com writes:
>
> > a tube known for hum
>
> Greets Jeets Neets,
>
> I think there is too much nasty gossip in this rather insecure hobby of ours.
> Too many slights and cheap shots and not enough really heart felt insults.
>
> Let us not spread rumors without having built and tuned and rebuilt circuits
> involving the unit under attack.
>
> Some people are known to use their facile nasty tongue to try and avoid doing
> any worthwhile work. Just smile and nod and try it for yourself if you are
> interested.
>
> Remember, there are very few technical problems which cannot be overcome with
> talent, imagination, hard work and lots of money :)
>
> If all of the above fail, please share your frustration so we do not waste
> time replicating your failures.
>
> But, make your comments meaningfully malicious and wound the garbage mortally.
>
> "Known for hum" is pretty weak stuff.
>
> Happy Ears!
> Al B^}
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: Re: [JN] 26 pre (Steve)
Date: Mon, 24 Jan 2000 22:51:11 -0600
Source: Sound Digest Archive v02.n416
- -----Original Message-----
From: St. Cinnamon <ram@ispnook.com>
To: TubeGarden@aol.com <TubeGarden@aol.com>
Cc: sound@deliverator.io.com <sound@deliverator.io.com>
Date: 24 January, 2000 10:26 PM
Subject: Re: [JN] 26 pre (Steve)
someone wrote:
>> Let us not spread rumors...
and you replied:
>The 26 being a direct heated triode can be
>difficult to get silent in a pre-amp application,
The 26 isn't just known for hums. It
actually does hum.
The 26 sounds better humming on AC than
quiet on batteries. I just listened through the
hum for a while. The tube was so magical that,
well, what hum. Ronan's work producing a
board for cascaded voltage regulators, feeding
a current regulator, was necessary because
this tube requires such a careful, detailed
filament supply.
--Carter
=========================================================================
From: "St. Cinnamon" <ram@ispnook.com>
Subject: Re: [JN] 26 pre (Steve)
Date: Mon, 24 Jan 2000 23:12:14 -0500
Source: Sound Digest Archive v02.n416
Al,
I did not write "a tube known for hum", if you are going to make
comments, especially negative ones you could at least read the posted
emails well enough to decipher who said what.
In fairness to the individual that did make this comment, he is not far off.
The 26 being a direct heated triode can be difficult to get silent in a
pre-amp application, and yes Al I have built and tuned and rebuilt circuits
involving this tube.
Ritchie
Original Message -----
From: <TubeGarden@aol.com>
To: <sound@io.com>
Sent: Monday, January 24, 2000 12:02 AM
Subject: Re: [JN] 26 pre (Steve)
> In a message dated 1/23/00 7:18:50 PM US Mountain Standard Time,
> ram@ispnook.com writes:
>
> > a tube known for hum
>
> Greets Jeets Neets,
>
> I think there is too much nasty gossip in this rather insecure hobby of
ours.
> Too many slights and cheap shots and not enough really heart felt insults.
>
> Let us not spread rumors without having built and tuned and rebuilt
circuits
> involving the unit under attack.
>
> Some people are known to use their facile nasty tongue to try and avoid
doing
> any worthwhile work. Just smile and nod and try it for yourself if you are
> interested.
>
> Remember, there are very few technical problems which cannot be overcome
with
> talent, imagination, hard work and lots of money :)
>
> If all of the above fail, please share your frustration so we do not waste
> time replicating your failures.
>
> But, make your comments meaningfully malicious and wound the garbage
mortally.
>
> "Known for hum" is pretty weak stuff.
>
> Happy Ears!
> Al B^}
>
>
>
>
>
=========================================================================
From: "Dave Slagle" <dslagle@earthlink.net>
Subject: Re: [JN] 26 pre (Steve)
Date: Mon, 24 Jan 2000 23:30:39 -0500
Source: Sound Digest Archive v02.n416
fwiw... the 26 was designed for battery use, and if operated any other way,
it is the fault of the user for the hum... al's comments were wise and in my
eyes quite positive and to me strike quite close to what this fourum is all
about.... now if somebody believes the hype that the 26 is wonderful, and
fails... they are the ones to blame not the tube... again the tube only does
only what we tell it to... if we tell it to hum... it is our fault...
thats like blaming a 417A for oscillating... its what it was designed to do.
220V power sucks... i plugged my amp into it and it blew up... don't ever
use that 220V power.
dave
=========================================================================
From: StepHydro@aol.com
Subject: Re: [JN] 26 pre (Steve)
Date: Tue, 25 Jan 2000 06:34:46 EST
Source: Sound Digest Archive v02.n416
In a message dated 01/25/2000 12:<BR26:<BR25 AM
Eastern Standard, Tim_Bailey@medibank.com.au writes:> I'm on 240volt's @
50hz down here. It hasn't killed my gear and it does
> resist
> RFI better.
>
> Empirically, this is supported by the slower growth here of the market for
> AC
> gear for audio.
>
> and where did that thread come from anyway?
Tim,
Son't be a galah ;-)
That was a bit of irony from Slagle. Easier to decode if you were folloowing
the "type 26 hum" thread.
Cheers/Don
=========================================================================
From: connlyra@gol.com
Subject: [JN] Re: 26 pre (Steve)
Date: Tue, 25 Jan 2000 16:13:37 +0900
Source: Sound Digest Archive v02.n416
Chris Beck <n9zes@execpc.com> wrote:
>However, there are definite rules in audio that there is consensus
>about - tubes rule!<
Sorry, but I must disagree. My experience is that the designer and
his or her level of comprehension and capability makes a bigger
difference than the technology.
Possibly thanks to the long history of tubes, there are many
topologies, circuit fragments and general know-how in the public and
semi-public domain (including mailing lists like the Joe-List),
making it fairly difficult to go wrong.
In semiconductors, there is still an ocean of topologies and circuits
that have yet to be tried out, so you could validly say that many
semiconductor designers are still in the process of "groping."
But in my experience, it is definitely possible to sonically outdo
many tube circuits with a clever semiconductor one.
Conversely, I suppose that a real wizard of a tube designer could
outperform my existing best efforts, too.
Dave Slagle has said, "Don't blame the tube, it doesn't know any
better." Well, the same is true for solid-state.
It is fine that you like and appreciate tubes. I do, too. But could
you please stop this uninformed straw-man bashing? Apart from making
some people feel good for a short time, I don't see that it
contributes anything useful.
regards
jonathan carr
PS. We have a chap in our company who is a fairly well-regarded tube
designer in Japan, so I have a reasonable idea of where my
semiconductor designs stand in relation to tubes.
=========================================================================
From: Tim_Bailey@medibank.com.au
Subject: Re: [JN] 26 pre (Steve)
Date: Tue, 25 Jan 2000 16:24:37 +1100
Source: Sound Digest Archive v02.n416
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hey dave slagle
I'm on 240volt's @ 50hz down here. It hasn't killed my gear and it does resist
RFI better.
Empirically, this is supported by the slower growth here of the market for AC
gear for audio.
and where did that thread come from anyway?
Tim B
=========================================================================
From: connlyra@gol.com
Subject: [JN] Re: 26 pre (Steve)
Date: Tue, 25 Jan 2000 19:49:31 +0900
Source: Sound Digest Archive v02.n416
Dave Slagle <dslagle@earthlink.net> wrote:
>220V power sucks. I plugged my amp into it and it blew up. Don't
>ever use that 220V power.<
In your personal experience, you mean.
Myself, I find 220/240V to be quite good. In fact, in many ways, I
prefer it over 100/117V. In my personal experience, of course.
Depending on the designer, the mileage may vary.
jc
=========================================================================
From: connlyra@gol.com
Subject: [JN] Re: 26 pre (Steve)
Date: Wed, 26 Jan 2000 00:41:47 +0900
Source: Sound Digest Archive v02.n417
Hi Chris
I have no disagreement with what you say. I reckon that the vast
library of circuits that have been both published and pre-scrutinized
by sonically discerning ears counts as a huge advantage for the
beginning tube designer.
As to if an SS circuit will always be more complex or not, I think it
depends on whether you care to include opamps or not - whether you
are considering the total number of active devices, including the
individual transistors etched onto each die, or whether you are
simply looking at the total number of physically separate parts that
you yourself have to deal with.
But even opamps can be made to work reasonably well.
I have a fairly popular US tube phono stage, one that originally
retailed for US$1500, and recently it was updated to the newer and
improved, US$2500 spec. Listening to it in my own and a few other
systems, it wasn't exactly bad, but it didn't have sufficient
resolution for even our midrange cartridge model (Clavis DC), nor did
it stand up to an opamp-based prototype phono stage that we were
working on for the CES.
Likewise, Junji Kimura and Kohji Teramura at 47 Labs (Sakura Systems)
have shown that you can make a fairly good-sounding range of products
that features semiconductors, opamps, global feedback, electrolytic
caps, metal-film resistors, and a whole range of other things that
many people regard as sonic no-nos.
So yes, the designer does matter.
I would also like to add that, personally, I feel that construction
is also a very big issue. As has been mentioned on this list, some
devices or topologies have a marked tendency to hum, others like to
oscillate, and still others may be sensitive to temperature. I find
that it is very important to not just understand the schematic
topology, but also to understand what various physical constructions
will introduce into the schematic in the way of parasitic
capacitances and inductances, leakage currents, thermal gradients,
common impedances, radiated fields etc, and account for these, either
in the schematic or the construction.
Best of luck in whatever you design!
regards
jonathan carr
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: Re: [JN] 26 pre (Steve)
Date: Tue, 25 Jan 2000 20:37:06 -0600
Source: Sound Digest Archive v02.n418
- -----Original Message-----
From: Tim_Bailey@medibank.com.au <Tim_Bailey@medibank.com.au>
To: Carter Hendricks <carter@i1.net>
Date: 24 January, 2000 11:28 PM
Subject: Re: [JN] 26 pre (Steve)
Tim wrote:
>aren't there plenty of tubes that sound almost
>as good a job but are easier to get right?
>
I'm the guy who listened to a 26, ac filaments,
and just ignored the hum. The 26 is that good.
True, my current CD line stage uses a 42.
Easy, powerful. But [as anyone who has read
Harry Potter to their child would agree] magic
is hard to give up. The 26 is magic. Maybe
like a WE 205D for the rest of us.
--Carter
By the way: the Sylvania book says "...26 is
intended for use in radio or audio frequency
stages of a-c operated recievers which
employ the 27 as a detector."
=========================================================================
From: Jim de Kort <sp@vt52.com>
Subject: Re: [JN] 26 pre (Steve)
Date: Wed, 26 Jan 2000 20:14:38 +0100
Source: Sound Digest Archive v02.n419
Hi,
>>aren't there plenty of tubes that sound almost
>>as good a job but are easier to get right?
You mean like an ECC82? The 26 is the best tube I have heard for preamps,
you have to try it to believe it. I've been dealing with hum so much that I
almost threw this tube out of the window, but the sound it produced even
with the hum was soooo good...
>By the way: the Sylvania book says "...26 is
>intended for use in radio or audio frequency
>stages of a-c operated recievers which
>employ the 27 as a detector."
RCA says the same, except for the 27 bit...
Regards,
Jim de Kort
jim@vt52.com
=========================================================================
From: "St. Cinnamon" <ram@ispnook.com>
Subject: Re: [JN] 26 pre (Steve)
Date: Thu, 27 Jan 2000 21:50:06 -0500
Source: Sound Digest Archive v02.n420
Hello Steve,
Presently I am using an old industrial power tranny but I recently
ordered a custom tranny from Electra-print. I will keep you posted on the
results of the new xfmr.
Ritchie
- ----- Original Message -----
From: Brooks, Steve <Steve.Brooks@turner.com>
To: 'St. Cinnamon' <ram@ispnook.com>
Sent: Thursday, January 27, 2000 3:10 PM
Subject: RE: [JN] 26 pre (Steve)
> Ritchie,
> Thanks for the tip on Electra-Print...what did you use for a power
transformer?
> Steve
>
> -----Original Message-----
> From: St. Cinnamon [mailto:ram@ispnook.com]
> Sent: Sunday, January 23, 2000 9:20 PM
> To: sound@deliverator.io.com
> Subject: Re: [JN] 26 pre (Steve)
>
>
> Steve,
> Yes, it is Jim DeKort's design, I am using Tom Ronan's filament boards
> and a separate power supply. With this combination I do not have any hum
> problems. The pre also has Electra-print plate load chokes, which are
> terrific.
> This is a great sounding tube, very musical (not hi-fi), well worth giving
> it a try especially if you already have the tubes.
> You can first try the circuit with a plate load resistor to see if you
like
> it. Jim DeKort was very helpful with any questions I had, as was Tom
Ronan.
> Give it a go there are alot of unselfish people in this hobby who would
> help you out if needed.
> Thanks,
> Ritchie
> ----- Original Message -----
> From: Brooks, Steve <Steve.Brooks@turner.com>
> To: 'St. Cinnamon' <ram@ispnook.com>
> Sent: Friday, January 21, 2000 9:44 AM
> Subject: RE: [JN] dact stepped attenuator
>
>
> > Ritchie,
> > Is that Jim DeKort's design that you built? I have some 26's and
> have been eyeing that
> > preamp, but I'm a novice at building and am a little concerned
> about trying a preamp..
> > especially with a tube known for hum.
> > Steve
> >
> > -----Original Message-----
> > From: St. Cinnamon [mailto:ram@ispnook.com]
> > Sent: Thursday, January 20, 2000 10:40 PM
> > To: sound@deliverator.io.com
> > Subject: [JN] dact stepped attenuator
> >
> >
> > I am looking for some feedback on the Danish audio connect (dact)
stepped
> attenuators. I'm presently using a noble pot in a choke loaded 26 pre. If
> anyone is presently using or has had experience with the dact, could you
> please pass on your findings.
> > thanks,
> > Ritchie
> >
> >
> >
>
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: [JN] 288 Drivers etc.
Date: Thu, 27 Jan 2000 16:30:28 -0800
Source: Sound Digest Archive v02.n420
Hi All,
Someone inquired about a pair of 288 drivers I have, and wanted me to
notify him if I ever decided to sell them, but I lost track of that
email. Anyway, I listed them and the W-5Ms, plus the Accuphase P-300
power amp on ebay. They close Sat and Sun. The reserves are quite
reasonable. So, anyone who is interested, here is the address:
http://cgi6.ebay.com/aw-cgi/eBayISAPI.dll?ViewListedItems&userid=danmarshall@worldnet.att.net
Thanks.
Dan Marshall
=========================================================================
From: "Henry Platt" <hnplatt@massed.net>
Subject: [JN] 295 Peramaters
Date: Sat, 08 May 1999 18:01:44 -0500
Source: Sound Digest Archive v02.n138
Dear Joes,
Does anyone have any info on operating this tube? it is a direct coupled
double triode in a globe 50 style envelope. Made by Speedy>
I need operating voltages and pinouts.
Thanks,
Henry Platt
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: [JN] 2A3 = 6B4G?
Date: Wed, 19 May 1999 14:22:30 -0700
Source: Sound Digest Archive v02.n147
Hi Nicholas,
The single plate 2A3 is more rare and much sought after by audiophiles.
You should test it and see if it is good. If so it will fetch a pretty
good price if you want to sell it. The down side is that it will cost a
fair bit to match it, assuming it is good.
Most folks claim the 2A3, 6A3 & 6B4Gs are equivalent except for the base
and, of course, the filament voltage. I have Tungsol, RCA and National
Union 6A3s which have plate structures identical to dual-plate 2A3s. I
also have CBS-Hytron, RCA, KenRad, National Union and Arcturus 6B4Gs
with entirely different physical plate structures than the 2A3/6A3
types. Their plate structures are like twin type-45 plates instead of
the usual 2A3 plate structure. I have not seen a 6B4G with a 2A3 type
plate structure. They apparently all have the same specs, however, some
claim that tubes with the dual 45 plate structure sound better than
those with the usual 2A3 type of plate structure. I haven't compared
them myself soundwise, so don't have an opinion. BTW, this is technical
tube stuff, isn't that off topic here nowdays.
Dan Marshall
Nicholas McKinney wrote:
>
> Hello Joes,
>
> I picked up a stash of old tubes yesterday and one in particular caught my
> eye after I got home. It is a 2A3 RCA Cunningham with what appears to be
> only a single plate. The plate is about 1" wide and 1/4" thick total. Is
> this something that I will have problems finding a matching mate for?
>
> Also what are the opinions of the 6A3 and the 6B4G compared to the 2A3
> soundwise? In my book the 6A3 is a 6V filament version of the 2A3, and the
> 6B4G is an octal base version of the 6A3. There has to be more to it than
> that.
>
> Thanks
>
> Nick
=========================================================================
From: "Mike Hathaway" <triode@t-three.com>
Subject: Re: [JN] 2A3 = 6B4G?
Date: Wed, 19 May 1999 15:26:52 -0700
Source: Sound Digest Archive v02.n147
I have a decent collection of mon-plate 2A3's, 6B4G's, 6A3's, and VT52's,
and I can attest to the fact that just about anything you can imagine does
in fact exist. I have 2 RCA-Cunningham SP 2A3's which are in fact
different, SP 6A3's that are identical to WE VT52's, and even a couple of SP
National Union 6B4G's which are different still, and look for all the world
to derived from the VT25A non-ceramic support version. My contention has
always been that the various tube manufactures shipped whatever they had
laying around, or in many cases could be purchased from another supplier. I
think this was especially true during the big war. Far and away the biggest
usage for 2A3 tubes was as pass elements in military power supplies. That
being the case, the vendors would have been foolish to try and change the
government spec, but to win the business they were always pushing to beef up
their products to achieve a better service record. The original 15/18 watt
dissipation rating is highly suspect. It looks about right for the SP 2A3,
but the dual 45 version should have a 20 watt dissipation rating, since each
section is rated at 10 watts. The later dual-W plate (as I call it) looks
to have even higher dissipation, but they were constrained to supply tubes
to the government's specs. We've seen reports here of running Chinese 2A3's
way over the spec, but I suspect you could do the same with any late vintage
NOS version without problem. Sadly, after having said all that - the SP
2A3's IMHO are indeed superior to the other versions. They hum balance much
better, have much better low-level detail, and paint a much more stable
image, and the others are right - you'll pay through the nose to find a
mate. My wish for you is that it is in fact DOS (dead old stock), because
you'll have a lovely display piece, without having to sell your children to
pair it up, nor will you at some point off in the future pay even more to
replace them, or suffer with more common versions of the tube.
Mike
- -----Original Message-----
From: Grover Gardner <groverg@postoffice.att.net>
To: Nicholas McKinney <nick@lambdacoustics.com>
Cc: sound@lists.io.com <sound@lists.io.com>
Date: Wednesday, May 19, 1999 2:30 PM
Subject: Re: [JN] 2A3 = 6B4G?
>Oooh, lucky you, kind of! Those are had to find and a mate is going to be
>pretty expensive, if you can locate one. There was thread on RAT recently
>which discussed the differences between the mon- and bi-plate version of
the
>2A3. Someone felt that there was a difference in loading for the two two,
the
>mono-plate preferring a higher load than the bi-plate. Hmmmm... There are
of
>course the 6V versions of these tubes, but as far as I know they only come
in
>bi-plate versions. There is very little difference, I think, between the
6A3
>and 6B4G except for the basing. I've heard some people say that the 2A3
>sounds better because of the higher filament current. It's up to you,
really.
> If you're not into worrying about matching rare tubes, you might consider
>selling it and buying several bi-plates for what you get. Or ask around
and
>find a mate and build a very special amp. I think the consensus is that
the
>mono-plate is worth the trouble, but I don't have perosnal experience with
them.
>
>Nicholas McKinney wrote:
>>
>> Hello Joes,
>>
>> I picked up a stash of old tubes yesterday and one in particular caught
my
>> eye after I got home. It is a 2A3 RCA Cunningham with what appears to be
>> only a single plate. The plate is about 1" wide and 1/4" thick total.
Is
>> this something that I will have problems finding a matching mate for?
>>
>> Also what are the opinions of the 6A3 and the 6B4G compared to the 2A3
>> soundwise? In my book the 6A3 is a 6V filament version of the 2A3, and
the
>> 6B4G is an octal base version of the 6A3. There has to be more to it
than
>> that.
>>
>> Thanks
>>
>> Nick
>
>--
>Grover Gardner
>groverg@postoffice.att.net
>
=========================================================================
From: Nicholas McKinney <nick@lambdacoustics.com>
Subject: [JN] 2A3 = 6B4G?
Date: Wed, 19 May 1999 15:48:54 -0400
Source: Sound Digest Archive v02.n147
Hello Joes,
I picked up a stash of old tubes yesterday and one in particular caught my
eye after I got home. It is a 2A3 RCA Cunningham with what appears to be
only a single plate. The plate is about 1" wide and 1/4" thick total. Is
this something that I will have problems finding a matching mate for?
Also what are the opinions of the 6A3 and the 6B4G compared to the 2A3
soundwise? In my book the 6A3 is a 6V filament version of the 2A3, and the
6B4G is an octal base version of the 6A3. There has to be more to it than
that.
Thanks
Nick
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: [JN] 2A3 = 6B4G?
Date: Wed, 19 May 1999 16:32:54 -0700
Source: Sound Digest Archive v02.n147
I posted this earlier, but it was delivered to my mailbox as a blank
message, so here tis again.
Hi Nicholas,
The single plate 2A3 is more rare and much sought after by audiophiles.
You should test it and see if it is good. If so it will fetch a pretty
good price if you want to sell it. The down side is that it will cost a
fair bit to match it, assuming it is good.
Most folks claim the 2A3, 6A3 & 6B4Gs are equivalent except for the base
and, of course, the filament voltage. I have Tungsol, RCA and National
Union 6A3s which have plate structures identical to dual-plate 2A3s. I
also have CBS-Hytron, RCA, KenRad, National Union and Arcturus 6B4Gs
with entirely different physical plate structures than the 2A3/6A3
types. Their plate structures are like twin type-45 plates instead of
the usual 2A3 plate structure. I have not seen a 6B4G with a 2A3 type
plate structure. They apparently all have the same specs, however, some
claim that tubes with the dual 45 plate structure sound better than
those with the usual 2A3 type of plate structure. I haven't compared
them myself soundwise, so don't have an opinion. BTW, this is technical
tube stuff, isn't that off topic here nowdays.
Dan Marshall
Nicholas McKinney wrote:
>
> Hello Joes,
>
> I picked up a stash of old tubes yesterday and one in particular caught my
> eye after I got home. It is a 2A3 RCA Cunningham with what appears to be
> only a single plate. The plate is about 1" wide and 1/4" thick total. Is
> this something that I will have problems finding a matching mate for?
>
> Also what are the opinions of the 6A3 and the 6B4G compared to the 2A3
> soundwise? In my book the 6A3 is a 6V filament version of the 2A3, and the
> 6B4G is an octal base version of the 6A3. There has to be more to it than
> that.
>
> Thanks
>
> Nick
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 2A3 = 6B4G?
Date: Wed, 19 May 1999 16:51:16 -0400
Source: Sound Digest Archive v02.n147
Oooh, lucky you, kind of! Those are had to find and a mate is going to be
pretty expensive, if you can locate one. There was thread on RAT recently
which discussed the differences between the mon- and bi-plate version of the
2A3. Someone felt that there was a difference in loading for the two two, the
mono-plate preferring a higher load than the bi-plate. Hmmmm... There are of
course the 6V versions of these tubes, but as far as I know they only come in
bi-plate versions. There is very little difference, I think, between the 6A3
and 6B4G except for the basing. I've heard some people say that the 2A3
sounds better because of the higher filament current. It's up to you, really.
If you're not into worrying about matching rare tubes, you might consider
selling it and buying several bi-plates for what you get. Or ask around and
find a mate and build a very special amp. I think the consensus is that the
mono-plate is worth the trouble, but I don't have perosnal experience with them.
Nicholas McKinney wrote:
>
> Hello Joes,
>
> I picked up a stash of old tubes yesterday and one in particular caught my
> eye after I got home. It is a 2A3 RCA Cunningham with what appears to be
> only a single plate. The plate is about 1" wide and 1/4" thick total. Is
> this something that I will have problems finding a matching mate for?
>
> Also what are the opinions of the 6A3 and the 6B4G compared to the 2A3
> soundwise? In my book the 6A3 is a 6V filament version of the 2A3, and the
> 6B4G is an octal base version of the 6A3. There has to be more to it than
> that.
>
> Thanks
>
> Nick
- --
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: trs@carlsmith.com
Subject: Re: [JN] 2A3 = 6B4G? -Reply
Date: Wed, 19 May 1999 13:02:58 -1000
Source: Sound Digest Archive v02.n147
Mike-
Have you had a chance to compare either the KR or VV
single-plate 2A3 types to your original 2A3 monoplates?
Tom Sylvester trs@carlsmith.com
>>> "triode@t-three.com" 05/19/99 01:01pm >>>
I have a decent collection of mon-plate 2A3's, 6B4G's, 6A3's,
and VT52's,
and I can attest to the fact that just about anything you can
imagine does
in fact exist.
* * *
Sadly, after having said all that - the SP
2A3's IMHO are indeed superior to the other versions. They
hum balance much
better, have much better low-level detail, and paint a much
more stable
image, and the others are right - you'll pay through the nose
to find a
mate. My wish for you is that it is in fact DOS (dead old
stock), because
you'll have a lovely display piece, without having to sell your
children to
pair it up, nor will you at some point off in the future pay even
more to
replace them, or suffer with more common versions of the
tube.
Mike
=========================================================================
From: "Michael B. Hathaway" <triode@t-three.com>
Subject: Re: [JN] 2A3 = 6B4G? -Reply
Date: Wed, 19 May 1999 17:01:52 -0700
Source: Sound Digest Archive v02.n147
Tom:
Yeah, I have a decent collection of VV tubes (32/300/52), and for full range
I much prefer the VV's, but if I were doing a biamp, which I may some day,
I'd choose the SP 2A3's, because they are absolutely breath-taking in the
mids and highs. Since most of the music I listen to is fairly complex, I
like the extra headroom and slam, and I think you'd need to match SP 2A3's
with a strong LF amp to get there, but I suspect that if you could work out
all the matching problems you'd really have something. Sadly, I'm the lazy
type, and tend to listen more than tweak. I'm currently running VV300B's,
and they offer a very balanced presentation. Having said all that, I think
for the money the VV/KR tubes are an excellent tube when compared to the
other premium tubes out there, including SP 2A3's and WE300B's.
Mike
- ----- Original Message -----
From: <trs@carlsmith.com>
To: <triode@t-three.com>; <sound@lists.io.com>
Sent: Wednesday, May 19, 1999 4:02 PM
Subject: Re: [JN] 2A3 = 6B4G? -Reply
Mike-
Have you had a chance to compare either the KR or VV
single-plate 2A3 types to your original 2A3 monoplates?
Tom Sylvester trs@carlsmith.com
>>> "triode@t-three.com" 05/19/99 01:01pm >>>
I have a decent collection of mon-plate 2A3's, 6B4G's, 6A3's,
and VT52's,
and I can attest to the fact that just about anything you can
imagine does
in fact exist.
* * *
Sadly, after having said all that - the SP
2A3's IMHO are indeed superior to the other versions. They
hum balance much
better, have much better low-level detail, and paint a much
more stable
image, and the others are right - you'll pay through the nose
to find a
mate. My wish for you is that it is in fact DOS (dead old
stock), because
you'll have a lovely display piece, without having to sell your
children to
pair it up, nor will you at some point off in the future pay even
more to
replace them, or suffer with more common versions of the
tube.
Mike
=========================================================================
From: "spaaaz" <spaaaz@ameritech.net>
Subject: [JN] 2a3
Date: Thu, 14 Oct 1999 21:36:04 -0700
Source: Sound Digest Archive v02.n302
well folks i just got back from about 2 hours of listening to
the soliloquy 2a3 speakers and all i can say is.wow
ordered a pair in curly maple with stands these are some of the nicest
stands ive seen.guess i better get the second laurel amp built asap.
ill keep ya posted on thier breaking in.anyone got a good deal on
some we300b's?
mike
=========================================================================
From: ROBERT PETERSON <robertpeterson56@yahoo.com>
Subject: [JN] 2A3 HUMdinger followup
Date: Mon, 1 Oct 2001 10:53:25 -0700 (PDT)
Source: Sound Digest Archive v02.n986
Much thanks for the numerous responses to my hum
difficulty. I did have the hum pots and can't imagine
building a DHT amp without them. I tried an improvised
2-point ground scheme and the hum level was no lower,
but interestingly it was no higher either. Increasing
the value of the capacitor following the choke from
47mf to 100mf got it quiet enough for me (at least for
awhile.) My speakers are about 100dB efficient and I
listen about 8 feet from them. I still may try
increasing the value of that capacitor a bit more but
I had nothing larger on hand. Were I to build it again
I believe that an extra L/C section would work out for
me but as it is set up now I can't quite find room for
another choke. Concerning grounding schemes though I
am interested in the reasons some prefer a 2-point
method. I was researching this on the web and I found
a custom guitar amp guy who swears by this method and
of course, Sakuma the Japanese builder of monster
transmiting tube amps, also seems to attribute a low
hum level to this grounding scheme. Anyway, I'm very
happy with the 2A3 SE sound. It's much more revealing
than my 6L6 SE/UL amp which really was very good too.
Thanks again.
__________________________________________________
Do You Yahoo!?
Listen to your Yahoo! Mail messages from any phone.
http://phone.yahoo.com
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] 2A3 HUMdinger followup
Date: Mon, 01 Oct 2001 20:28:43 +0200
Source: Sound Digest Archive v02.n986
dear Robert
The 2 point grounding ethod works fine for DC, ay frequencies above will
suffer from running in huge loops (draw the way currents run and you will
be surprised)
I am writing an article on layout and wiring, but time is still limiting me
to finish that (I have a house to renovate, a job at Philips (>50 hours a
week at present): Wish I could spend some more time on audio related
subjects ......
best regards
- -
Guido
At 10:53 1-10-01 -0700, ROBERT PETERSON wrote:
>Much thanks for the numerous responses to my hum
>difficulty. I did have the hum pots and can't imagine
>building a DHT amp without them. I tried an improvised
>2-point ground scheme and the hum level was no lower,
>but interestingly it was no higher either. Increasing
>the value of the capacitor following the choke from
>47mf to 100mf got it quiet enough for me (at least for
>awhile.) My speakers are about 100dB efficient and I
>listen about 8 feet from them. I still may try
>increasing the value of that capacitor a bit more but
>I had nothing larger on hand. Were I to build it again
>I believe that an extra L/C section would work out for
>me but as it is set up now I can't quite find room for
>another choke. Concerning grounding schemes though I
>am interested in the reasons some prefer a 2-point
>method. I was researching this on the web and I found
>a custom guitar amp guy who swears by this method and
>of course, Sakuma the Japanese builder of monster
>transmiting tube amps, also seems to attribute a low
>hum level to this grounding scheme. Anyway, I'm very
>happy with the 2A3 SE sound. It's much more revealing
>than my 6L6 SE/UL amp which really was very good too.
>Thanks again.
>
>__________________________________________________
>Do You Yahoo!?
>Listen to your Yahoo! Mail messages from any phone.
>http://phone.yahoo.com
=========================================================================
From: "Carter Hendricks" <carter@i1.net>
Subject: Re: [JN] 2a3 line stage
Date: Sun, 3 Sep 2000 12:44:52 -0500
Source: Sound Digest Archive v02.n652
- ----- Original Message -----
From: Joerg Buschmann <101.27598@germanynet.de>
To: <sound@lists.io.com>
Sent: 03 September, 2000 4:13 AM
> switching on the 2a3 line-stage...
> so: who has done it before?
Not the 2A3 but I have built a 42 and 46
line stage. The 42 is, of course, IDH.
Triode wired and choke loaded, it
brought a lot of power to the music.
The 46, also choke loaded, but with
a current regulated filament supply, has
the power and the directed heated magic.
I think power tubes make great line
stages.
--Carter
=========================================================================
From: Michael and Bonnie Thomas <thomas@cybertours.com>
Subject: [JN] 2a3 noises agian!
Date: Thu, 27 May 1999 21:51:14 -0400
Source: Sound Digest Archive v02.n154
Anyone have experience with an occasional thumping sound from an amp.
Once the amp warms up for 40 minutes or so. it will make a audible dull
thump - thump - thump sound. Seens to be coming from one monoblock and
not the other. Swapped tubes and issue still occurs, thought this might
be a curcuit problem that others have seen. Not sure what to look for
here.
Mike
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 2a3 noises agian!
Date: Mon, 31 May 1999 13:53:14 -0400
Source: Sound Digest Archive v02.n159
- --
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 2a3 noises agian!
Date: Mon, 31 May 1999 13:59:21 -0400
Source: Sound Digest Archive v02.n159
Sorry about the blank messages again. Mike, it sounds to me like you are
having some serious RF and motorboating problems. Since it's not specific to
the tubes, it could be a number of things.
Lack of decoupling in the power supply.
You've tapped into some resonance in the power supply--are your choke and
capacitor values staggered? If you line up two or more LC filter stages of
the same value this can occur.
Could be some interaction between the amp and preamp--an RF problem or an
excess of gain in the overall audio chain, something like that.
Could be something as simple as a loose solder joint on a tube socket.
Or a leaky coupling cap.
Can you send or describe, at least to me, the circuit you're using? Maybe
I/we will spy something amiss...
Michael and Bonnie Thomas wrote:
>
> Anyone have experience with an occasional thumping sound from an amp.
>
> Once the amp warms up for 40 minutes or so. it will make a audible dull
> thump - thump - thump sound. Seens to be coming from one monoblock and
> not the other. Swapped tubes and issue still occurs, thought this might
> be a curcuit problem that others have seen. Not sure what to look for
> here.
>
> Mike
- --
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: Bill Sadler <sadlerb@mweb.co.za>
Subject: re:[JN] 2A3 SE Diode Biased Amp
Date: Sun, 19 Aug 2001 11:07:47 +0200
Source: Sound Digest Archive v02.n949
Steve and Allen,
Thanks Steve for your response and links, where the hell do you get the time
to initiate a web site like this ?.
And thanks to Allen for your response, I wouldn't have in a million years
thought of biasing my driver tube to 2.5 volts with a 6AS7 power tube and as
for your 2A3 operating points, so much for Herb Reicherts comments about
running triodes with high voltages and high currents in deep class A1. Nice
one.
Regards
Bill Sadler
=========================================================================
From: "Gary E. Kaufman" <gkaufman@bu.edu>
Subject: [JN] RE: 2A3 substitution...
Date: Fri, 8 Oct 1999 06:34:51 -0400
Source: Sound Digest Archive v02.n296
It was the 27GB5/PL500 he suggested. There is also a 6GB5/EL500 as well as
a 13GB5/XL500 and 18GB5/LL500.
I briefly looked into this until I priced the plate cap and Magnoval sockets
I'd need. Any savings on the tube rapidly was depleted by the cost of the
sockets, cap and hassle of the plate cap.
I'd be curious as to what they actually sound like if any one has tried
this.
- Gary
EMAIL: gkaufman@the-planet.org
Web: http://www.the-planet.org
> Date: Fri, 8 Oct 1999 09:38:23 +1000
> From: "Hugh R. Dean" <aspen@alphalink.com.au>
> Subject: [JN] 845 circuit
>
> Have you seen Rikard Berglund's 1995 GA article on replacements
> for triodes?
> He touts the 27GK5 (I may have the designation wrong; article presently
> with a friend), an old TV tube, as the electrical equivalent of
> the 2A3 when
> wired as triode. He says they distort even less than the 2A3 and
> aside from
> a 27VAC 0.3A filament, they are plug in replacement. They cost $5.60.
> Hmmmmm...
=========================================================================
From: Michael and Bonnie Thomas <thomas@cybertours.com>
Subject: [JN] 2A3 thoughts
Date: Fri, 23 Apr 1999 18:14:48 -0400
Source: Sound Digest Archive v02.n130
Hi joes.
Was using chinese 2a3 - they say electron tube, made in china on them
to break in my moondogs. My second kit accomplishment.
Anyway, still somewhat a FNG - I slapped in a set of RCA 2a3 I picked up
from a dude who probably nows as much about tubes as I do.
Although they measured the same on his tester (68). One of the tubes has
more blue gas the "dances with the music" on the top of the tube. This
also produces a dull scrathy sound with my ear to the speaker. The other
tube is a little brighter at the bottom of the plate. Is this tube going
to cook? The both sound noticably better than the chinese tubes.
Any advice on the matter would be appreciated.
Mike
=========================================================================
From: Joseph Lowe <jlowe@cdc.net>
Subject: Re: [JN] 2A3 thoughts
Date: Fri, 23 Apr 1999 22:14:59 -0400 (EDT)
Source: Sound Digest Archive v02.n130
On Fri, 23 Apr 1999, Michael and Bonnie Thomas wrote:
> Although they measured the same on his tester (68). One of the tubes has
> more blue gas the "dances with the music" on the top of the tube.
That is actually good. It signifies a hard vacuum.
> This also produces a dull scrathy sound with my ear to the speaker.
Is the glow between the elements or just on the glass? if it's between the
elements, the tube is gassy. If it's on the glass, that is just stray
electrons striking the glass making it glow. A gassy tube can make noise,
but the noise can be from other causes as well.
> The other
> tube is a little brighter at the bottom of the plate. Is this tube going
> to cook?
What do yo mean by brighter? The filament, blue glow, or what?
>The both sound noticably better than the chinese tubes.
> Any advice on the matter would be appreciated.
Relax and enjoy the music.
=========================================================================
From: TubeGarden@aol.com
Subject: [JN] 2A3 to 45
Date: Wed, 29 Aug 2001 21:29:01 EDT
Source: Sound Digest Archive v02.n957
- --part1_153.20ed73.28bef0dd_boundary
Content-Type: text/plain; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
Greets!
I replaced the 2A3s with 45s.
Tube diode bias and a 1.6K OPT sound good. 2.56Vac fils, 238 V B+
GE Rcv Book says 4.6K, I will try it, but, this ain't bad, not bad at all.
Happy Ears!
Al B^}
- --part1_153.20ed73.28bef0dd_boundary
Content-Type: text/html; charset="US-ASCII"
Content-Transfer-Encoding: 7bit
<HTML><FONT FACE=arial,helvetica><BODY BGCOLOR="#ffffff"><FONT SIZE=2>Greets!
<BR>
<BR>I replaced the 2A3s with 45s.
<BR>
<BR>Tube diode bias and a 1.6K OPT sound good. 2.56Vac fils, 238 V B+
<BR>
<BR>GE Rcv Book says 4.6K, I will try it, but, this ain't bad, not bad at all.
<BR>
<BR>Happy Ears!
<BR>Al B^}
<BR>
<BR></FONT></HTML>
- --part1_153.20ed73.28bef0dd_boundary--
=========================================================================
From: ToobWiz@aol.com
Subject: Re: [JN] 2A3 to 45
Date: Wed, 29 Aug 2001 21:37:41 EDT
Source: Sound Digest Archive v02.n957
In a message dated 08/29/2001 9:<BR35:<BR13 PM
Eastern Daylight , TubeGarden@aol.com writes:
> GE Rcv Book says 4.6K, I will try it, but, this ain't bad, not bad at all.
Al,
What OPTs do you have at 4.7K?
Cheers/Don carron
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: [JN] 2A3 Update
Date: Thu, 16 Sep 1999 09:20:25 -0400
Source: Sound Digest Archive v02.n278
Another DHT Zombie joins the ranks of the undead. I got my latest creation
up and running this Sunday, and after a little tweaking I have it set up
well enough to enjoy (it sounded great already when first set up wrong, I
might add!)
This amp is similar to the DC Double Darling except that it uses 2A3 power
tubes and puts out a bit more power - quite a bit I'd say, not having scoped
it yet. In common with the DCDD it uses a single power supply tap for both
driver and output tube (~380V) and the driver is again an 8532. This is
loaded by a 34K resistor (2 x 68K in parallel,) and its plate sits at about
112 V. The cathode is self-biased with a 100 ohm resistor, unbypassed, and
at 1 V bias is passing 10mA. The grid resistor is 470K. (Anybody have some 100 ohm carbon comps for
a
Joe? Or better yet some 33K/5W non-inductive WW's?) The 2A3 is operating
with plate volts = 380, cathode volts = 150, and bias of (112-150) = 38V,
and drawing 54mA of current. The cathode R's are 2775 ohm, (2K5/25W in
series with 250/5W, with a 50 ohm humpot) bypassed by 100uF TSHA's. Nothing
fancy parts-wise, but all decent quality stuff.
I got some nice Audio Note T-144 outputs (secondhand, lightly used) and they
seem to be a cut above the Hammond or Champ transformers, or maybe it's
those 2A3's that are the cut above. Hum is inaudible through my little Radio
Shack Minimus 7's, 5.6mV left and 6.7mV right. (Steve, I may not bother with
the hum reduction mod, I'm sorry!)
Anyway I'll jump ahead to the key question :
How does it sound? Well, it's pretty lush, very, very involving (it's only
been off when the soldering iron's been on since I built it) and the extra
weight and power as compared to the DCDD is most welcome : I can rock out
quite a bit better than before. I guess one way to get to the point where
you are happy with 3 or 4 watts is to start with 1 or 2. There is a lot of
high end and low end, and all the instruments are well integrated. There are
a lot of intimate, low level details (Clifford Brown's lipwork, for example)
that really add excitement to the music. There is a definite, clearly
defined soundstage and it is pretty roomy.
All in all I'd say I find this to have been well worth the effort and a
significant upgrade.
I expect I will try clipleading these transformers into the DCDD and see
what portion of the improvement is simply due to the good iron. I also want
to try squeezing a little more current through the 2A3's and seeing whare
that gets me. Dave Slagle suggested 215V/70mA as a good low 'n' hot 2A3
operating point and I think I will be able to try that, by adjusting the
8532 loads and maybe the 2A3 cathode R's a little.
One thing I did find in getting this amp set up is it helps to have a half
dozen or more 8532's handy, to match up a pair : the whole thing is hard to
juggle if the 8532's don't bias up the same, and I found wide variation
between the tubes I had on hand.
- -j
- --
=====================================
Jeremy Epstein .... jepstein@shwd.com
=====================================
=========================================================================
From: dslagle@earthlink.net (dave slagle)
Subject: Re: [JN] 2A3 Update
Date: Thu, 16 Sep 1999 10:58:54 -0400
Source: Sound Digest Archive v02.n279
(Anybody have some 100 ohm carbon comps for a Joe? Or better yet some
33K/5W non-inductive WW's?)
Now Hear this... Manhattans last surplus shop is downsizing and moving to
brooklyn...Clark Reiss... 53 Leonard St. they will have your resistors....
On the topic of non-inductive wirewounds.... am i off base when i question
if they are needed in a plate circuit?
when you talk about 10K.... whats a few mh of inductance going to do???
> Dave Slagle suggested 215V/70mA as a good low 'n' hot 2A3
I actually suggested this as a reasonable way for J to deal with the B+
voltage at hand... if it were me... and knowing J is using chinese 2å3's i
would suggest something more like 250V and 70-80ma.... but thats me being a
crazy kid...
dave
=========================================================================
From: bobcx@earthlink.net
Subject: Re: [JN] 2A3 Update
Date: Thu, 16 Sep 1999 12:37:37 -0400
Source: Sound Digest Archive v02.n279
- ----- Original Message -----
From: dave slagle <dslagle@earthlink.net>
To: <sound@deliverator.io.com>
Sent: Thursday, September 16, 1999 10:58 AM
Subject: Re: [JN] 2A3 Update
> (Anybody have some 100 ohm carbon comps for a Joe? Or better yet some
> 33K/5W non-inductive WW's?)
>
> Now Hear this... Manhattans last surplus shop is downsizing and moving to
> brooklyn...Clark Reiss... 53 Leonard St. they will have your
resistors....
>
When it comes to tubes and electronic surplus, one of the best is Leeds in
Brooklyn. The have almost anything you can think of.
http://www.leedselect.com Phone 718-963-1764
Bob
=========================================================================
From: dslagle@earthlink.net (dave slagle)
Subject: Re: [JN] 2A3 Update
Date: Wed, 29 Sep 1999 16:55:42 -0400
Source: Sound Digest Archive v02.n289
>At 10:58 16/09/99 -0400, dave slagle wrote:
>> (Anybody have some 100 ohm carbon comps for a Joe? Or better yet some
>>33K/5W non-inductive WW's?)
Ironically, i am looking for just the opposite.... i hate resistors, and
resistances... i wish i could do away with them.... i try to get as close
to non-resistive inductors as i can...
>Some induction is allowed untill you yoa reach 33 k at let me say 20 kHz.
>My calculator says 260 mH. So do not pay too much attention to "low"
>inductance
i agree... i would love to see someone wind an inductive resistor for tube
products... just imagine what a clever marketing guy could do with that!
i remember on several occasions people mentioning the use of both a
resistor and inductor in series to load a tube to get some of the best of
both worlds... you know a 10hy choke and a 10K resistor for a tube like a
5687... the resistor giving acceptable bass response, and the inductor
giving a more horizontal loadline....
does anyone have any real experiences with this???
I guess this in the end, is just a way to cheap out, and not spring for a
high quality plate choke...
dave
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] 2A3 Update
Date: Wed, 29 Sep 1999 21:24:51 +0200
Source: Sound Digest Archive v02.n289
At 10:58 16/09/99 -0400, dave slagle wrote:
> (Anybody have some 100 ohm carbon comps for a Joe? Or better yet some
>33K/5W non-inductive WW's?)
Some induction is allowed untill you yoa reach 33 k at let me say 20 kHz.
My calculator says 260 mH. So do not pay too much attention to "low"
inductance
Always consider the total loop impedance
Guido
>Now Hear this... Manhattans last surplus shop is downsizing and moving to
>brooklyn...Clark Reiss... 53 Leonard St. they will have your resistors....
>
>On the topic of non-inductive wirewounds.... am i off base when i question
>if they are needed in a plate circuit?
>
>when you talk about 10K.... whats a few mh of inductance going to do???
>
>> Dave Slagle suggested 215V/70mA as a good low 'n' hot 2A3
>
>I actually suggested this as a reasonable way for J to deal with the B+
>voltage at hand... if it were me... and knowing J is using chinese 2å3's i
>would suggest something more like 250V and 70-80ma.... but thats me being a
>crazy kid...
>
>dave
>
>
>
>
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: [JN] 2c51
Date: Wed, 24 Mar 1999 15:42:31 +0100
Source: Sound Digest Archive v02.n090
Joes,
has anybody of you used 2c51 or 396a as voltage gain stage in a power
amp? If so, how did you like the tube? And what would you suggest as
operating points?
tia
christian
=========================================================================
From: Dan Kerl <dlkerl@ro.com>
Subject: Re: [JN] 2c51
Date: Wed, 24 Mar 1999 10:36:12 -0600
Source: Sound Digest Archive v02.n091
Christian Rintelen wrote:
> has anybody of you used 2c51 or 396a as voltage gain stage in a power
> amp? If so, how did you like the tube? And what would you suggest as
> operating points?
I'm going to use one in my Brook clone (replacing first 6SN7). Note
that
these are based upon calculation (haven't had the time to put it
together
yet).
Numbers I worked out are at this point:
voltage amp:
supply voltage: 290 V
plate load: 68K
cathode resistor: 290 ohms, unbypassed, no NFB
resulting bias voltage: 1.0 V
resulting plate voltage: 80 V
resulting quiescent plate current: 3.1 mA
realized voltage gain: 30
phase splitter (uses same supply rail, direct coupled to previous
stage):
plate and cathode resistors: 33.1 K, 1%
resulting plate voltage: 207 V
resulting cathode voltage: 83 V
resulting plate current: 2.5 mA
realized voltage gain: 0.88
The output of the phase splitter will be capacitvely coupled to the
drivers, which are 5687 halves (I'm going to try finding one that has
matched halves in my stash).
- --
Dan Kerl
dlkerl@ro.com
=========================================================================
From: rbales@gte.net (Ron Bales)
Subject: Re: [JN] 2c51
Date: Tue, 23 Mar 1999 12:20:43 GMT
Source: Sound Digest Archive v02.n092
On Wed, 24 Mar 1999 15:42:31 +0100, you wrote:
>Joes,
>has anybody of you used 2c51 or 396a as voltage gain stage in a power
>amp? If so, how did you like the tube? And what would you suggest as
>operating points?
I'm using 407A (same thing with 20/40V heaters) in my PP 6A3 amp:
http://home1.gte.net/rbales/index.htm
I'm running them with -3.1Vdc on the grid from a pair of AA batteries
connected to the center tap of the input trannie; 180V on the plate
loaded with a CT AF choke, ala Brook, from MagneQuest.
Good tube.
ROn
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: Re: [JN] re: 2CV (off topic) Haflinger
Date: Fri, 06 Aug 1999 09:25:05 +0200
Source: Sound Digest Archive v02.n226
I've had my fair share of driving Haflingers and Pinzgauers in the Swiss
army which bought plenty of them in the 60s and 70s. The Haflingers were
both versatile and dangerous -- because they were so light and so
manoeuvrable, people did more and more risky things with them. Many of
them crashed into steep canyons etc. But you're right, these small and
light AWDs could pass almost everywhere. Even in the Swiss alps... ;-)
(BTW I've seen some equipped with machine guns and mortars. Looks
absolutely ridicoulous!
The Pinz is another story. It's fast and dangerous, expecially the 3
axle AWD, because of the high center of gravity. There is also a two
axle AWD Pinzgauer which is less prone to topple over because wheel base
is slightly different. The Pinz was one of the worst gasoline guzzlers
around, despite its smallish power plant. What I hated most about them
was their noise -- the aircooled engine and the gearbox made an
obnoxiuos high-pitched whining noise that forced one to wear earplugs if
more than 30 km were to be driven on open roads. The 6WD ate tires like
mad becuse the wheel base was too short for a 3axle car on normal roads.
One ride across the alps and you needed to replace some serious
rubber...
Swiss army sold its Haflingers a couple of years ago and (AFAIK)
replaced them with horses, mules and 'copters. The Pinz is still used,
30 or so years after first put to service. But they're being replaced by
a Swiss made 2- and 3axle AWD. Although Austria is our neighbour, we
seem to suffer from the NIH (not invented here) syndrom....
Christian
Ian McPhail wrote:
> All this talk of 2CV's reminds me of an amazing vehicle a friend
> once owned in the late 70's. It was powered by an air cooled four
> stroke 600cc flat twin.
> No, not the BMW Isetta (a micro car simliar to the Heinckel and
> Messerschmidt) but the Haflinger. Named after a small breed of
> mountain horse and built by the Austrian company
> Steyr-Daimler-Puch. (Puch also built motor scooters)
> Rear engined like a VW, some crazies used to hot rod their
> Haflinger by squeezing in a VW flat four.
> Forget your 90's RV's, the Haflinger was one serious off road
> vehicle with true FWD (you could engage diff locks on both axles)
> and could handle up to 50 degrees sideways before rolling (no
> problem, being small, three guys could tip them back!)
> Top speed on road was a blistering 65kph. Sold new in the late
> 70's in Oz for around $3500.
> Once you owned a Haflinger what you really lusted after was its big
> brother the Pinzgauer, inllne six powered six wheel drive with three
> diff locks. Very Serious! Check them out.
> Steyr Daimler Puch All Wheel Drives
> http://4wd.sofcom.com/Steyr/Steyr.html
> regards Ian
>
> Ian McPhail i.mcphail@rmit.edu.au
> RMIT Chem and Met Eng Dept 110
> GPO Box 2476V
> Melbourne 3001
> Australia
> tel +61 3 9925 2408
> tel +61 3 9925 3326
> fax +61 3 9925 3746
- --
Christian Rintelen Konzept und Text
Dufourstrasse 165 CH-8008 Zurich Switzerland
Phone +41 1 420 11 55 Fax +41 1 420 11 57
mailto:rintelen@datacomm.ch
=========================================================================
From: "Ian McPhail" <i.mcphail@rmit.EDU.AU>
Subject: [JN] re: 2CV (off topic) Haflinger
Date: Fri, 6 Aug 1999 10:43:47 +1000
Source: Sound Digest Archive v02.n226
All this talk of 2CV's reminds me of an amazing vehicle a friend
once owned in the late 70's. It was powered by an air cooled four
stroke 600cc flat twin.
No, not the BMW Isetta (a micro car simliar to the Heinckel and
Messerschmidt) but the Haflinger. Named after a small breed of
mountain horse and built by the Austrian company
Steyr-Daimler-Puch. (Puch also built motor scooters)
Rear engined like a VW, some crazies used to hot rod their
Haflinger by squeezing in a VW flat four.
Forget your 90's RV's, the Haflinger was one serious off road
vehicle with true FWD (you could engage diff locks on both axles)
and could handle up to 50 degrees sideways before rolling (no
problem, being small, three guys could tip them back!)
Top speed on road was a blistering 65kph. Sold new in the late
70's in Oz for around $3500.
Once you owned a Haflinger what you really lusted after was its big
brother the Pinzgauer, inllne six powered six wheel drive with three
diff locks. Very Serious! Check them out.
Steyr Daimler Puch All Wheel Drives
http://4wd.sofcom.com/Steyr/Steyr.html
regards Ian
Ian McPhail i.mcphail@rmit.edu.au
RMIT Chem and Met Eng Dept 110
GPO Box 2476V
Melbourne 3001
Australia
tel +61 3 9925 2408
tel +61 3 9925 3326
fax +61 3 9925 3746
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: [JN] re: 2CV (off topic) Haflinger
Date: Fri, 06 Aug 1999 18:56:08 GMT
Source: Sound Digest Archive v02.n227
On Fri, 06 Aug 1999 09:25:05 +0200, Christian Rintelen
<rintelen@datacomm.ch> wrote:
>I've had my fair share of driving Haflingers and Pinzgauers in the Swiss
>army which bought plenty of them in the 60s and 70s.
Ever see the Rotax 2WD motorcycle?
- --dnb
=========================================================================
From: Christian Rintelen <rintelen@datacomm.ch>
Subject: [JN] 2CV, was: And its CFs again...
Date: Wed, 04 Aug 1999 17:53:57 +0200
Source: Sound Digest Archive v02.n221
Torsten.Loesch@enhar-ha.nthames.nhs.uk wrote:
> CV-2 indeed. A true lemon, oops Citroen of a Car. Also known as the "Ugly
> Duckling"....
It's called 2 CV, "Deux Chevaux" for it's two fiscal horspowers. 600 cc two
cyl air cooled boxer engine and undeadable. Not very fast though.
Christian
=========================================================================
From: Douglas Purl <dcp@selway.umt.edu>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Wed, 4 Aug 1999 13:15:48 -0600 (MDT)
Source: Sound Digest Archive v02.n222
On Wed, 4 Aug 1999, David Barnett wrote:
> On Wed, 04 Aug 1999 17:53:57 +0200, Christian Rintelen
> <rintelen@datacomm.ch> wrote:
>
> >It's called 2 CV, "Deux Chevaux" for it's two fiscal horspowers. 600 cc two
> >cyl air cooled boxer engine and undeadable.
>
> Agreed. The 2CV is one of the few cars that can be driven all day at
> flat-out full-throttle without a second though. 'Course,
> full-throttle in a 2CV is still within most posted highway speed
> limits...
I recall the sales brochure for the douche vaux illustrating that its
seats could be removed and used for picnic furniture. Now there's a
luxury feature.
Cathode, the way down. BTW, this is what the list should be debating.
Doug Purl
=========================================================================
From: Ken Gilbert <ride5000@ride.ri.net>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Wed, 04 Aug 1999 15:46:05 -0400
Source: Sound Digest Archive v02.n222
>Return-Path: <owner-sound@lists.io.com>
>From: davidbarnett@aristotle.net (David Barnett)
>>It's called 2 CV, "Deux Chevaux" for it's two fiscal horspowers. 600 cc two
>>cyl air cooled boxer engine and undeadable.
>
>Agreed. The 2CV is one of the few cars that can be driven all day at
>flat-out full-throttle without a second though. 'Course,
>full-throttle in a 2CV is still within most posted highway speed
>limits...
There must be SOME simple mods one can do to that engine to squeeze a
little more Pout! I mean, that's a rather despicable power/displacement
ratio. Motorcycle engines are encroaching on the 100hp/600cc range, for
god's sake.
The compression must be 2:1.
Hell, hot-rod it and throw in a 5.5HP Tecumseh lawnmower engine ;-)
They really must last forever at that kind of minimal mechanical stress.
KG
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Wed, 04 Aug 1999 18:28:49 GMT
Source: Sound Digest Archive v02.n222
On Wed, 04 Aug 1999 17:53:57 +0200, Christian Rintelen
<rintelen@datacomm.ch> wrote:
>It's called 2 CV, "Deux Chevaux" for it's two fiscal horspowers. 600 cc two
>cyl air cooled boxer engine and undeadable.
Agreed. The 2CV is one of the few cars that can be driven all day at
flat-out full-throttle without a second though. 'Course,
full-throttle in a 2CV is still within most posted highway speed
limits...
- --dnb
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Wed, 04 Aug 1999 18:05:02
Source: Sound Digest Archive v02.n223
A 01:15 PM 8/4/99 -0600, Douglas Purl a écrit :
>On Wed, 4 Aug 1999, David Barnett wrote:
>
>> On Wed, 04 Aug 1999 17:53:57 +0200, Christian Rintelen
>> <rintelen@datacomm.ch> wrote:
>>
>> >It's called 2 CV, "Deux Chevaux" for it's two fiscal horspowers. 600 cc
two
>> >cyl air cooled boxer engine and undeadable.
>>
>> Agreed. The 2CV is one of the few cars that can be driven all day at
>> flat-out full-throttle without a second though. 'Course,
>> full-throttle in a 2CV is still within most posted highway speed
>> limits...
>
>I recall the sales brochure for the douche vaux illustrating that its
>seats could be removed and used for picnic furniture. Now there's a
>luxury feature.
>
>Cathode, the way down. BTW, this is what the list should be debating.
>
>Doug Purl
Painted in psychedelic livery, the "Deux Chevaux" made a cute alternative
to the VW Beetle ...
dbk
=========================================================================
From: "David B. Klein" <dklein@microtec.net>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Wed, 04 Aug 1999 18:17:49
Source: Sound Digest Archive v02.n223
A 09:36 AM 8/5/99 +1200, Owen Young a écrit :
>
>
>Ken Gilbert wrote:
>>> The compression must be 2:1.
>
>For the record:
>Compression ratio ranged from 7.75:1 to 9:1!
>Engine displacements 425cc to 602cc flat twin air cooled.
>
>Introduced 50yrs ago, durable like good tubes.
>
>Owen
>
>
Wonder how they would fare on an emission test ...
dbk
=========================================================================
From: Allen Wright <AllenVSE@compuserve.com>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Wed, 4 Aug 1999 19:56:21 -0400
Source: Sound Digest Archive v02.n223
Ken puzzled:
>>>There must be SOME simple mods one can do to that engine to squeeze a
little more Pout! I mean, that's a rather despicable power/displacement
ratio. Motorcycle engines are encroaching on the 100hp/600cc range, for
god's sake.
The compression must be 2:1.<<<
Nope - 2HP is not 2 BHP - the french have some way of calculating the tax
for a car from it's displacement - based on the efficiencies from 1911 or
so.
They actually make 30bhp or so - someone will know precisely.
Saw a motormag story on a turbo'd one - ran really great till it burned...
Allen (VSE)
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Thu, 05 Aug 1999 01:10:27 GMT
Source: Sound Digest Archive v02.n223
On Wed, 04 Aug 1999 15:46:05 -0400, Ken Gilbert <ride5000@ride.ri.net>
wrote:
>There must be SOME simple mods one can do to that engine to squeeze a
>little more Pout! I mean, that's a rather despicable power/displacement
>ratio. Motorcycle engines are encroaching on the 100hp/600cc range, for
>god's sake.
That's two fiscal, or taxable horsepower, not two actual brake
horsepower. I think a 2CV was good for at least 25-30BHP. Still
nowhere near what a motorcycle engine will do, but I bet it has more
torque than a motorcycle engine, too.
- --dnb
=========================================================================
From: davidbarnett@aristotle.net (David Barnett)
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Thu, 05 Aug 1999 01:25:40 GMT
Source: Sound Digest Archive v02.n223
On Wed, 04 Aug 1999 18:17:49, "David B. Klein" <dklein@microtec.net>
wrote:
>Wonder how they would fare on an emission test ..
It's for this reason that the 2CV was withdrawn from the US market
after the 1966 model year.
- --dnb
=========================================================================
From: Owen Young <oyoung@clear.net.nz>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Thu, 05 Aug 1999 09:36:05 +1200
Source: Sound Digest Archive v02.n223
Ken Gilbert wrote:
>> The compression must be 2:1.
For the record:
Compression ratio ranged from 7.75:1 to 9:1!
Engine displacements 425cc to 602cc flat twin air cooled.
Introduced 50yrs ago, durable like good tubes.
Owen
=========================================================================
From: Owen Young <oyoung@clear.net.nz>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Thu, 05 Aug 1999 09:46:24 +1200
Source: Sound Digest Archive v02.n223
Ken Gilbert wrote:
>> The compression must be 2:1.
For the record:
Compression ratio ranged from 7.75:1 to 9:1!
Engine displacements 425cc to 602cc flat twin air cooled.
Introduced 50yrs ago, durable like good tubes.
Owen
=========================================================================
From: Owen Young <oyoung@clear.net.nz>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Thu, 05 Aug 1999 14:11:04 +1200
Source: Sound Digest Archive v02.n223
Allen Wright wrote:
>
> They actually make 30bhp or so - someone will know precisely.
Allen's correct...
21 to 35BHP depending on displacement at 5000-6000rpm
Apologies, off topic digression.
Owen
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Thu, 05 Aug 1999 23:33:50 +0200
Source: Sound Digest Archive v02.n225
At 17:53 04/08/99 +0200, Christian Rintelen wrote:
>
>
>Torsten.Loesch@enhar-ha.nthames.nhs.uk wrote:
>
>> CV-2 indeed. A true lemon, oops Citroen of a Car. Also known as the "Ugly
>> Duckling"....
>
>It's called 2 CV, "Deux Chevaux" for it's two fiscal horspowers. 600 cc two
>cyl air cooled boxer engine and undeadable. Not very fast though.
I used to have a Dyane (luxe version) once I was a student. 602 CC, 2 stage
carburator and electronic ignition. Did 140 km an hour though
Not to forget the open roof, for sunny days in France and Spain and even
Holland
Guido
>Christian
>
>
>
>
>
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Thu, 05 Aug 1999 23:33:51 +0200
Source: Sound Digest Archive v02.n225
>Agreed. The 2CV is one of the few cars that can be driven all day at
>flat-out full-throttle without a second though. 'Course,
>full-throttle in a 2CV is still within most posted highway speed
>limits...
and it runs pretty well in hot desserts due to air cooling
Guido
>--dnb
>
>
>
=========================================================================
From: Grover Gardner <groverg@postoffice.att.net>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Sat, 07 Aug 1999 08:54:52 -0400
Source: Sound Digest Archive v02.n228
Plus, the damn things are like billy goats, better than most of these
so-called SUVs they make now--they'll go absolutely anywhere with that high
carriage, light body and front-wheel drive. But parts are just unobtainium in
the US anymore. And I wouldn't want to meet up with even a medium-sized SUV
in one...
Owen Young wrote:
>
> Ken Gilbert wrote:
> >> The compression must be 2:1.
>
> For the record:
> Compression ratio ranged from 7.75:1 to 9:1!
> Engine displacements 425cc to 602cc flat twin air cooled.
>
> Introduced 50yrs ago, durable like good tubes.
>
> Owen
- --
Grover Gardner
groverg@postoffice.att.net
=========================================================================
From: evaguido <EvaGuido@iaehv.nl>
Subject: Re: [JN] 2CV, was: And its CFs again...
Date: Sat, 07 Aug 1999 12:48:07 +0200
Source: Sound Digest Archive v02.n228
>There must be SOME simple mods one can do to that engine to squeeze a
>little more Pout! I mean, that's a rather despicable power/displacement
>ratio. Motorcycle engines are encroaching on the 100hp/600cc range, for
>god's sake.
I knew a German fellow tuning 2CVs
>The compression must be 2:1.
>
>Hell, hot-rod it and throw in a 5.5HP Tecumseh lawnmower engine ;-)
>
>They really must last forever at that kind of minimal mechanical stress.
The motors don't. 150.000 km is normal and 250.000 km exceptional
Guido
>KG
>
>
=========================================================================
From: "Daniel J. Marshall" <danmarshall@worldnet.att.net>
Subject: Re: [JN] 2E22 curves
Date: Fri, 27 Aug 1999 15:55:56 -0700
Source: Sound Digest Archive v02.n264
Kurt Th. Steffensen wrote:
>
> Hawk !
>
> I am about to play with one of my recent favorite tubes 2E22.
> I used to have the curves on the HD.
> I can´t from where I got these down loaded , and the HD has
> been taken away from our world by the ghost of Bxxx Gxxxx !
> (Don´t say his name out loud , as this might kill the hard disc !! )
>
> Has anyone the curves ?
> (Or do I have to do without them ? )
Nooooo Kurt. You don't have to do without them, you have to plot them,
then send a copy to me, both triode and pentode, unless some kind soul
comes up with them. I have been collecting them for while now too.
Dan Marshall
>
> Sincerely
> - Kurt Steffensen
=========================================================================
From: "Kurt Th. Steffensen" <kurt-steffensen@teliamail.dk>
Subject: [JN] 2E22 curves
Date: Sat, 28 Aug 1999 00:33:05 +0300
Source: Sound Digest Archive v02.n264
Hawk !
I am about to play with one of my recent favorite tubes 2E22.
I used to have the curves on the HD.
I can´t from where I got these down loaded , and the HD has
been taken away from our world by the ghost of Bxxx Gxxxx !
(Don´t say his name out loud , as this might kill the hard disc !! )
Has anyone the curves ?
(Or do I have to do without them ? )
Sincerely
- - Kurt Steffensen
=========================================================================
From: connlyra@gol.com
Subject: [JN] 2 interesting digital audio links
Date: Sat, 24 Jun 2000 17:51:35 +0900
Source: Sound Digest Archive v02.n590
http://www.kenwoodcorp.com/i/topframes/press_sdrive_20000620.html
This one is mainly designed for MP3 enhancement, and the information
is quite sparse, but it is mentioned that "This technology can also be
used to improve the fidelity of FM playback."
Now for something which personally I find quite interesting.
http://www.etl.go.jp/etl/divisions/%7Eacoustic/research/nxtgen-e.html
or
http://www.etl.go.jp/etl/divisions/%7Eacoustic/research/nxtgen-j.html
It reiterates what much research has already stated, that the
extended frequency range or SuperAudio has no directly audible impact
by itself. It would seem that other mechanisms are the source of the
sonic differences:
a) Distortion in the following devices
b) Relaxation of the following analog filter structre
c) Relaxation in the digital domain
Interesting that Mr. Ashihara found bullshit data on the disc. Does
someone want to fool the audio community, or is this simply another
example of lax(ative) quality standards?
regards
jonathan carr
=========================================================================
From: blackie <tubesville@yahoo.com>
Subject: [JN] 2phat2B4gotten
Date: Sat, 6 May 2000 03:10:03 -0700 (PDT)
Source: Sound Digest Archive v02.n541
son, son!
jc smokin' dat chronic again...shit.
L8R
=====
blackie
blackie@tubesville.com
www.tubesville.com
__________________________________________________
Do You Yahoo!?
Send instant messages & get email alerts with Yahoo! Messenger.
http://im.yahoo.com/
=========================================================================
From: jc@izone.com
Subject: Re: [JN] 2phat2B4gotten
Date: Sat, 06 May 2000 08:08:58 -0400
Source: Sound Digest Archive v02.n541
well, there's also "phat hed", and "phat phace", either one works well for
me. oh, and watta bout "2phat n phresh outta dumb shit 2say"... man, i
drink too much coffee.
jc
=========================================================================
From: "Murray Leshner" <multi-volti@softhouse.com>
Subject: [JN] 2 questions
Date: Thu, 13 Jul 2000 03:07:46 -0400
Source: Sound Digest Archive v02.n602
Hello
1) can someone tell me what the odd tube is being discussed in phono front
end with 2SK mosfet? 417A? 5842?
2) Long shot...looking for unwanted Personal Network Analyzer (appeared in
QST 1/98-2/98)
Thanks
Murray
=========================================================================
From: "Multi-Volti Devices" <multi-volti@softhouse.com>
Subject: [JN] 2 questions: DHT's and CD-R
Date: Wed, 26 May 1999 00:23:37 -0400
Source: Sound Digest Archive v02.n151
Hello:
Two questions for the group:
1) Anyone remember the procedure (and reference or source for the procedure)
for 'rejuvenating' low-emission filaments of DHT transmitting tubes
(tetrodes also)?
I'm looking for % increase in filament voltage and duration of this
condition. I have seen published info on filament temperature to do this,
but I cannot measure the filament temperature, while I can measure filament
voltage.
2) Regarding use of CD-R/RW drives with analog input signal:
It's easy to 'copy' audio CD's with the Adaptec Direct-CD software that
comes with CD-R/RW drives. What's not as clear to me is whether one can and
how one can record analog input audio to CD. According to the manual in my
drive (HP8110i), I can record inout audio as .wav. This can be played back
on a computer, but I don't think can be played by 'conventional' CD-ROM
players (home and automotive).
I'm wondering if the 'full version' of the Adaptec software or some other
software allows the saving of files as .cda (CD audio).
Also, how good a job can such a sound cards do with analog audio, say from a
turntable? I'm not looking for esoteric Joelist-quality, just something that
at least exceeds the quality of typical audio cassette.
Thank you
Murray
=========================================================================
From: Eric Weitzman <eweitzman@acm.org>
Subject: RE: [JN] 2 questions: DHT's and CD-R
Date: Thu, 27 May 1999 11:38:40 -0700
Source: Sound Digest Archive v02.n154
You wrote,
> From: Multi-Volti Devices [SMTP:multi-volti@softhouse.com]
> Subject: [JN] 2 questions: DHT's and CD-R
> 2) Regarding use of CD-R/RW drives with analog input signal:
> It's easy to 'copy' audio CD's with the Adaptec Direct-CD software that
> comes with CD-R/RW drives. What's not as clear to me is whether one can
and
> how one can record analog input audio to CD. According to the manual in
my
> drive (HP8110i), I can record inout audio as .wav. This can be played
back
> on a computer, but I don't think can be played by 'conventional' CD-ROM
> players (home and automotive).
For an incredible wealth of information, check out the usenet FAQ on
CD-R/RW at
http://www.fadden.com/cdrfaq
This FAQ covers everything you'd ever want to know about CD-R/RW, including
getting music files from WAV to audio CDs, inter-track timing, etc, etc...
For example:
Subject: [2-20] How do WAV/AIFF files translate into Red Book CD audio?
(1998/05/20)
There is absolutely nothing special about the audio data encoded on a CD.
The
only difference between a "raw" 44.1KHz 16-bit stereo WAV file and CD
audio is
the byte ordering.
It isn't necessary to convert a WAV or AIFF file to a special format to
write to a CD,
unless you're using some proprietary coding (like MP3 compression) that
doesn't
have a system-recognized codec. Similarly, you don't have to do anything
special
to audio extracted from a CD. It's already in a format that just about
anything can
understand.
Just put your audio into the correct format -- 44.1KHz, 16-bit, stereo,
uncompressed
(a/k/a PCM) -- and the software you use to write CDs will do the rest. All
of the
fancy error correction and track indexing stuff happens at a lower level.
or,
Subject: [2-15] What are "jitter" and "jitter correction"?
(1998/04/06)
The first thing to know is that there are two kinds
of jitter that relate to audio CDs. The usual meaning of
"jitter" refers to a time-base error when digital samples
are converted back to an analog signal; see
http://www.digido.com/jitteressay.html for a discussion. The
other form of "jitter" is used in the context of digital
audio extraction from CDs. This kind of "jitter" causes
extracted audio samples to be doubled-up or skipped
entirely. (Some people will correctly point out that the
latter usage is an abuse of the term "jitter", but we seem
to be stuck with it.)
<snip>
or,
Subject: [3-3] How do I get rid of hisses and clicks
on audio CDs? (1998/10/12)
If you're interested in removing noise from audio
captured from an analog source, such as a record player or
analog cassette tape, skip to section (3-12). This section
is about unexpected noise in audio from digital sources,
such as tracks extracted from a CD.
The single most important rule of noise removal is to figure
out where the noise came from. Play the .WAV files off of
your hard drive (if you're doing direct CD-to-CD copies,
extract a track and listen to it). If you hear noise in the
.WAV on your hard drive, the digital audio extraction isn't
working very well. You either need to extract more slowly,
extract from a different device, find a program that works
better, or maybe just clean the dust and grime off the
source CD. For more information, including a URL for the
CD-DA FAQ, see section (3-2).
If the problem sounds like repeated or skipped samples,
rather than clicks or hissing, the problem is probably
jitter during extraction. See section (2-15) for an
overview.
<huge snip>
or,
Subject: [3-12] How do I transfer my records or cassettes to
a CD? (1999/03/23)
The tricky part in doing this -- unless you have a
stand-alone audio CD recorder -- is getting the audio
transferred to your computer and modifying it to suit your
tastes. The act of writing a sound file onto a CD is fairly
trivial with most recorders and software. If you're
considering the purchase of a computer-connected recorder
for transferring tapes or LPs to CD, you should worry less
about the recorder and more about the quality of the
digitized audio. Few, if any, people will insist that
recorder A produces better quality audio CD-Rs than recorder
B, but everybody has an opinion about sound cards.
Start with http://homepages.nildram.co.uk/~abcomp/lp-cdr.htm
and http://www.octave.com/library/outsidesource.html, and
read through
http://www.octave.com/library/audiocd.html. These go into a
lot more detail than this section does.
If you have questions or need a recommendation on a
sound card, you might want to try:
news:rec.audio.tech
news:comp.sys.ibm.pc.soundcard.tech
Some highly technical benchmark evaluations of cards are
available at http://www.rockpark.com/soundcards/ and
http://www.pcavtech.com/.
<huge snip>
HTH,
- - Eric
- -----Original Message-----
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: [JN] 2SK146/7 Replacements
Date: Tue, 12 Oct 1999 11:37:55 -0600
Source: Sound Digest Archive v02.n300
Hi All:
For those who are looking for an equiv to the Toshiba 2SK147 and the
matched dual-147, the 2SK146; InterFET in the US make drop-in replacements
that are IFN147 and IFN146 respectively.
Their "site" can be found at:
http://www.techexpo.com/firms/interfet.html
but there's little more there than contact info - a small company but very
nice people
Bill Perkins,
PEARL, Inc.
Unit 200, 2137 33rd Ave. S.W.,
Calgary, Ab.,
Canada T2T 1Z7
Ph. 1 403 244 4434 Fx. 1 403 244 9026
=========================================================================
From: KevinC927@aol.com
Subject: Re: [JN] 2SK146/7 Replacements
Date: Tue, 12 Oct 1999 17:38:57 EDT
Source: Sound Digest Archive v02.n300
In a message dated 10/12/99 13:41:27, custserv@pearl-hifi.com writes:
<< For those who are looking for an equiv to the Toshiba 2SK147 and the
matched dual-147, the 2SK146; InterFET in the US make drop-in replacements
that are IFN147 and IFN146 respectively.
Their "site" can be found at:
http://www.techexpo.com/firms/interfet.html
but there's little more there than contact info - a small company but very
nice people >>
As of my last contact with them, there was a pretty large line item minimum.
Kevin Carter
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: Re: [JN] 2SK146/7 Replacements
Date: Tue, 12 Oct 1999 23:45:37 -0600
Source: Sound Digest Archive v02.n300
Kevin Carter wrote
SNIP
> As of my last contact with them, there was a pretty large line item minimum.
>
> Kevin Carter
=======================
Hi Kevin, All:
Yes, it seems to me that it is 250 pcs of so and I forget the price just
now . . . . I'll find out and post that info
Bill - PEARL, Inc.
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: Re: [JN] 2SK146/7 Replacements
Date: Fri, 15 Oct 1999 11:18:17 +0100 (BST)
Source: Sound Digest Archive v02.n302
Bill,
Many thanks for the into.
Would anyone be interested in placing a joint order? The minimum order
is 250 USD and I really don't want about 100 of these things.
Simon
On Tue, 12 Oct 1999, PEARL Cust Serv wrote:
> Hi All:
> For those who are looking for an equiv to the Toshiba 2SK147 and the
> matched dual-147, the 2SK146; InterFET in the US make drop-in replacements
> that are IFN147 and IFN146 respectively.
> Their "site" can be found at:
>
> http://www.techexpo.com/firms/interfet.html
>
> but there's little more there than contact info - a small company but very
> nice people
>
>
>
> Bill Perkins,
> PEARL, Inc.
> Unit 200, 2137 33rd Ave. S.W.,
> Calgary, Ab.,
> Canada T2T 1Z7
> Ph. 1 403 244 4434 Fx. 1 403 244 9026
>
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: Andrej Deticek <andrej.deticek@siol.net>
Subject: Re: [JN] 2SK146/7 Replacements
Date: Fri, 15 Oct 1999 13:11:56 +0100
Source: Sound Digest Archive v02.n302
If one needs only a few pcs. of 2SK147, it might be more practical to
order them from Erno Borbely, who charges DEM 10.00/each (about $ 5.50):
http://home.earthlink.net/~borbelyaudio/index5.htm
He can also supply matched sets at extra price.
Andrej Deticek
________________________________________________________________________________________
Simon Busbridge wrote:
>
> Bill,
>
> Many thanks for the into.
>
> Would anyone be interested in placing a joint order? The minimum order
> is 250 USD and I really don't want about 100 of these things.
>
> Simon
>
> On Tue, 12 Oct 1999, PEARL Cust Serv wrote:
>
> > Hi All:
> > For those who are looking for an equiv to the Toshiba 2SK147 and the
> > matched dual-147, the 2SK146; InterFET in the US make drop-in replacements
> > that are IFN147 and IFN146 respectively.
> > Their "site" can be found at:
> >
> > http://www.techexpo.com/firms/interfet.html
> >
> > but there's little more there than contact info - a small company but very
> > nice people
> >
> >
>
=========================================================================
From: Simon Busbridge <S.C.Busbridge@bton.ac.uk>
Subject: [JN] 2SK147
Date: Wed, 31 Mar 1999 10:09:01 +0100 (BST)
Source: Sound Digest Archive v02.n102
Hi
Does anyone have the specs for this fet?
TIA
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: flegal@allaban.fr (Francois Yves Le Gal)
Subject: Re: [JN] 2SK147
Date: Wed, 31 Mar 1999 12:14:07 +0200
Source: Sound Digest Archive v02.n102
At 10:09 31/03/99 +0100, you wrote:
>Does anyone have the specs for this fet?
Must have got them at home in one of Hiraga's books.
But, if I do remember correctly, it's long been out of production and
replaced by the 2SK170 (different packaging, slightly better specs).
A .pdf spec sheet for the '170 can be downloaded from Toshiba's website
http://doc.semicon.toshiba.co.jp/pdf_j/docweb123/j001374.pdf
François Yves Le Gal flegal@allaban.fr
Directeur Associé
Allaban WebSystems Tél : + 33(0)1 4106 9500
43, rue Raspail Fax : + 33 (0)1 4756 0305
F-92300 Levallois-Perret http://www.allaban.fr
=========================================================================
From: "PEARL Cust Serv" <custserv@pearl-hifi.com>
Subject: [JN] 2SK147 Data Sheet in PDF
Date: Sun, 11 Feb 2001 15:43:07 -0700
Source: Sound Digest Archive v02.n804
Hi All:
For any who want it, I now have in PDF the 4 pg. data sheet for the
Toshiba 2SK 147 low noise JFET. Additionally, I have the IFN146/7 data
sheets as well.
"Zipped," these are 750K and 128K respectively.
Best regards,
Bill - PEARL, Inc.
A new scientific truth does not triumph by convincing its opponents
and making them see the light. But rather because its opponents
eventually die. Neils Bohr
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: [JN] 2SK147, Loesch preamp, etc.
Date: Mon, 03 Jan 2000 09:15:32 -0500
Source: Sound Digest Archive v02.n382
Reading between the lines of Allen Wright's VSE website, maybe he can't
get any more 2SK147's and has shifted to other Toshiba JFET's, 2SK369
and 2SK170 (same JFETs but inside a lower-dissipation case.) At first
attempt these appear no easier to source than the '147, here in the US.
Is there a cheap, functionally equivalent and almost-as-good substitute
for us tinkerers who want to try a proof-of-concept (read : blow up a
few cheap ones while we learn) run at the cascode input RIAA circuits?
I'm hoping I can source these parts at the same time as my resistors &
caps from someplace like Digi-Key or Mouser. I know about the matching
etc., this is just an alpha-test to see if I can build the thing, after
which I will most likely pop for a pair (or quad for burnout insurance!)
of the ones available from Joe and Allen.
Thorsten, you have swayed me with your endorsement of the Loesch preamp
with cascode input, I have some 417A's on the way so I'm going to try
and build that one before the end of the next K-year. I have a couple of
questions :
You use the Loesch circuit as drawn except the input tube looks like
this:
>
>
>
|
___
- - ------->ground
--,
|
|
drain
- -----|---gate
> source----VVVV-->ground
>
|
V
and the 2K7 is made 8K2 (dropper for B+ above the 10K plate load.)
Correct? What value of cathode R do you use, the schematic allows for a
range of values. Also one more question on the Loesch schematic :
Is the resistor just ahead of the RIAA out switch 4.7 ohm (Mills) or
4.7Megohm, I am confused. I think this is to "pull down" the output to 0
to prevent switch noise - is it necessary (assuming one's speaker's can
withstand the pops?)
Allen typically uses a 100R/330pf anti-AM-radio network at the input,
also uses a blocking cap at the input. Comments? Do you use either of
these, Thorsten?
Allen, I hope you aren't disappointed by my choice of circuit : one
factor is that I am considering the 417A's as a 2A3 driver tube too so I
will have a few in my house to get started with. Seems like a useful
tube from the specs.
- -j
=========================================================================
From: "T. Loesch" <ezee_e@hotmail.com>
Subject: [JN] Re: 2SK147, Loesch preamp, etc.
Date: Tue, 04 Jan 2000 10:40:59 GMT
Source: Sound Digest Archive v02.n384
Hi there,
>Is there a cheap, functionally equivalent and almost-as-good substitute for
>us tinkerers who want to try a proof-of-concept (read : blow up a few cheap
>ones while we learn) run at the cascode input RIAA circuits?
2SK170
You will not find them with palces like Mouser or Digi-Key (I might be wrong
though). What you need is someone who stocks spares (Semiconductors) for Far
Eastern Equipment.... Look for places who sell all the obsolete STK Poweramp
Modules.... I found my 2SK147, 2SK170 and veritable treasure drove of other
stange and interesting stuff at such a place.
>You use the Loesch circuit as drawn except the input tube looks like
>this:
<snip>
>Correct?
Yes.
>What value of cathode R do you use, the schematic allows for a
>range of values.
50 Ohm.
>Is the resistor just ahead of the RIAA out switch 4.7 ohm (Mills) or
>4.7Megohm, I am confused.
4M7....
>I think this is to "pull down" the output to 0
Nope. It is part of the Biasing Network for the Final Stage (use the 5687
instead of the 6DJ8, it really does sound better, even against 1950's
vinatge Mullard Goldpin E88CC).
>to prevent switch noise - is it necessary (assuming one's speaker's can
>withstand the pops?)
It does pop quite loudely. I use use a 3-Position Toggle to give me both
Mono (down position) and Mute (Upward Position) after the Volume Control.
This is pretty non-invasive (if wired well) and gives me the ability to
spare speakers.
>Allen typically uses a 100R/330pf anti-AM-radio network at the input,
>also uses a blocking cap at the input. Comments? Do you use either of
>these, Thorsten?
Nope. I also do not use Grid Stoppers or Cathode Stoppers, all these have
been replaced by Ferrite Beads directly on the (cut down to size) Valve
Socket Pin's.
Later Thorsten
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
=========================================================================
From: Dan Kerl <dlkerl@ro.com>
Subject: Re: [JN] 2SK147, Loesch preamp, etc.
Date: Wed, 05 Jan 2000 08:52:51 -0600
Source: Sound Digest Archive v02.n387
Jeremy Epstein wrote:
>
> Reading between the lines of Allen Wright's VSE website, maybe he can't
> get any more 2SK147's and has shifted to other Toshiba JFET's, 2SK369
> and 2SK170 (same JFETs but inside a lower-dissipation case.) At first
> attempt these appear no easier to source than the '147, here in the US.
I recently (mid Nov) ordered 60 pieces 2SK369BL from MCM. I have so far
received 47 pieces (meaning that they're backordered), but they do list
them (Source Code : YM1099). MCM is the only domestic source for these
I've found to date.
- --
Dan Kerl
dlkerl@ro.com
=========================================================================
From: "Ellen Oler" <ellenoler@earthlink.net>
Subject: [JN] 2SK170
Date: Mon, 17 Jan 2000 09:05:14 -0500
Source: Sound Digest Archive v02.n406
David :
It was me who was bandying this about. I'm afraid you are late to the party,
because I have given away all the pairs I was able to match.
Buying 40 pieces, MCM charged $22.00, and they got them to me in about two
days, they are definitely NOT out of stock of 2SK170. 2SK147 is another
matter, only Erno Borbely seems to have them, at a *tough* price.
I built the matching jig illustrated in Allen Wright's book, I can send that
to you if you go that route and save you 10 bucks or so at Radio Shack
(where they DO have all the necessary parts if you choose to make your own.)
Out of 40 JFETs I got three pairs matched to three places on my DMM, about 4
or 5 pairs matched to .1mV, and only three pieces or so that I would
consider unmatched to any of the others. I made some loosely matched trios
(consisting of a well-matched pair and the nearest singleton) and no quads.
The whole process was a bit tedious but not the least bit difficult.
Hope this helps, sorry I can't send you a pair from this batch!
- -j (Jeremy Epstein, from home email a/c)
PS : BTW, what IS a "Plate Qualification Specialist"? - I've meant to ask
you.
=========================================================================
From: Jeremy Epstein <jepstein@shwd.com>
Subject: [JN] 2SK170 JFET OFFER CLOSED
Date: Wed, 12 Jan 2000 09:36:10 -0500
Source: Sound Digest Archive v02.n398
(I reserve the right to offer more of 'em after I get them in and match
them, but for now please hold off, or reply and be considered "wait
listed".)
- -j
- --
=========================================
Jeremy Epstein .........jepstein@shwd.com
=========================================
=========================================================================
From: "PEARL Cust. Service" <custserv@pearl-hifi.com>
Subject: [JN] 2uF/1500V Auricaps
Date: Mon, 01 Oct 2001 12:05:47 -0600
Source: Sound Digest Archive v02.n986
Hello All:
I have 4 pcs. of SiderealKap (now: AuriCap) 2.0uF @ 1500VDC brand new,
never used and Cyro-treated for sale for $US200.00 for the lot incl. airmail.
in the US, $US210.00 incl. int'l. air mail.
PayPal is my preferred method to receive payment although we can process
your credit card as well.
To have a look at the AuriCap page, click below:
http://www.audience-av.com/passive.htm
For pricing on these -- the current 1-10 price is $US54.30 ea -- click
below:
http://www.audience-av.com/auricap5.htm
Thanks . . .
Bill Perkins - PEARL, Calgary, Canada.
Tim Reese