A Stupid Idea [Archive] - AudioBanter.com

Bret L

April 18th 10, 08:59 AM

The latest AudioXPress has on its cover a stereo amplifier using one
4D32 tetrode in Class AB2 per channel as an output device.

Why do people persist in acts that aren't just stupid but willfully
destructive?

The 4D32 was neither designed for nor is it really any good as an
audio amplifier. Its only use today is as an RF output tube for the
beautifully built Collins V-line transmitters and a few military field
transmitters. The supply of these tubes is limited and it is doubtful
any more will ever be made. No really good substitute exists, although
the set can be kluged to operate at reduced power and efficiency with
the VHF twin triodes paralleled together.

Yet we have self centered and ****ish audiophools who persist.

Can you see why I get mad? If the 4D32 were a fantastic audio tube,
I'd say go ahead and use them up. Make them make more. But it is in
fact terrible. It sucks as an audio tube.

Even an 811 is far better. Rein Narma made them work just fine.

Patrick Turner

April 18th 10, 12:33 PM

On Apr 18, 5:59*pm, Bret L > wrote:
> *The latest AudioXPress has on its cover a stereo amplifier using one
> 4D32 tetrode in Class AB2 per channel as an output device.
>
> *Why do people persist in acts that aren't just stupid but willfully
> destructive?
>
> *The 4D32 was neither designed for nor is it really any good as an
> audio amplifier. Its only use today is as an RF output tube for the
> beautifully built Collins V-line transmitters and a few military field
> transmitters. The supply of these tubes is limited and it is doubtful
> any more will ever be made. No really good substitute exists, although
> the set can be kluged to operate at reduced power and efficiency with
> the VHF twin triodes paralleled together.
>
> *Yet we have self centered and ****ish audiophools who persist.
>
> *Can you see why I get mad? If the 4D32 were a fantastic audio tube,
> I'd say go ahead and use them up. Make them make more. But it is in
> fact terrible. It sucks as an audio tube.
>
> *Even an 811 is far better. Rein Narma made them work just fine.

Calm down me boy or you'll explode.

One could say an 807 was only meant for RF because there is a top cap
connection for the anode which reduces stray C and makes an amp less
likely to arc from anode to something nearby at lower potential.
Ditto a 6CM5/EL36. Except that the 6CM5 can give SE triode performance
better than a 2A3.
In PP, the ""queer"" 6CM5 line output beam tetrode can make 44W in AB,
and have low Ea, and only 4ka-a.
But 20W in PP near class A is possible. The hi-fi cognescenti and
audio magazines have always hated such tubes like they hate the
6L6.

As time marches along, fewer and fewer DIYer ppl are building anything
with vacuum tubes.
The old wannabes are decaying into decrepitude and or dreamers who
build nothing and can learn nothing, and who can't hear anything
properly.

Given the number of declining ppl making anything with vacuum tubes
and considering the number of tubes being sent to landfill, maybe tube
stocks or rare tubes are actually increasing if you say stocks =
number of tubes divided by users.

The last 20 years has seen a dramatic decline in people wanting to
take up amateur HF radio.
When one does venture out onto a ham band one finds oneself listening
for hours to yet another ancient old giza telling his story about his
bowel cancer operation or prostate troubles, and frankly, after the
first hour you become monumentally bored stiff. So there are these
mountains of suplus amateur radio gear out there lurking in sheds/
barns and gathering dust, fabulous antennas that cost a bomb 20 years
ago but now oxidizing to bits. And to resurrect an antena and its nice
mast on a suburban plot is so difficult because ot neighbours abd
concil regs etc, that only a masochist would bother to make his own
ham radio outfit.

At my wesbite I have around 100 odd different types of OPTs for sale
at prices similar to the lowest common denominator prices charged by
Hammond Engineering. The OPT mainly have C-cores and plenty of
interleaving but the interest from DIYer is almost ZERO.

In fact the total weight of all the transformers I have for sale is
over 1 tonne, and after 18 months I have sold two pairs and used
another two pairs in amps I have made for customers. At this rate when
I die in 10 months or 10 years there will still be a huge pile of
unsold trannys here and they will all go to the re-cyclers for the
cppper and iron if nobody buys them, and I strongly doubt anyone ever
will, even if I reduced the price by -12dB.

So it is with many old vacuum tubes. I know a guy who must be about 82
and last time I spoke to him he had 25,000 tubes AFTER having sold off
all the audio tubes in his collection. He's Morris Obrien at SanRemo
Vic, Aust. When he dies, the tubes in his estate might be auctioned
for $100 and the next die hard will have to find a barn and get
transport for them and then sort them out and that can take weeks of
work. But perhaps they end up all being crushed and secretly dumped to
avoid the problems with expenses of toxic material disposal.

There are some idiots who are trying to make tiny tube amps putting
out huge power for their size and the only way is to go class AB2 plus
a shirt&trouser load of negative feedback. There is a good market for
the 25yo dudes who can think of nothing cooler than having a tube amp
beside their PC for the headphones or small speakers.

So don't worry, be happy,

We all end up expiring.

Patrick Turner.

Watt? Me worry?

April 18th 10, 07:50 PM

> On Apr 18, 5:59*pm, Bitchy Loser wrote:
>
> > *The latest AudioXPress has on its cover a stereo amplifier using one
> > 4D32 tetrode in Class AB2 per channel as an output device.
>
> > *Why do people persist in acts that aren't just stupid but willfully destructive?

Hi RATs!

Some people are having a bit of fun, occasionally.

You could never imagine that, but, it happens, anyway.

Almost as if you are not the Supeme Being you assume...

Happy Ears!

Al

Bret L

April 18th 10, 09:04 PM

>
> At my wesbite I have around 100 odd different types of OPTs for sale
> at prices similar to the lowest common denominator *prices charged by
> Hammond Engineering. The OPT mainly have C-cores and plenty of
> interleaving but the interest from DIYer is almost ZERO.
>
> In fact the total weight of all the transformers I have for sale is
> over 1 tonne, and after 18 months I have sold two pairs and used
> another two pairs in amps I have made for customers. At this rate when
> I die in 10 months or 10 years there will still be a huge pile of
> unsold trannys here and they will all go to the re-cyclers for the
> cppper and iron if nobody buys them, and I strongly doubt anyone ever
> will, even if I reduced the price by -12dB.

Last I checked you were wanting considerably more than new Lars
Lundahl items. Those are a known quantity. I'd buy some if the price
were right, certainly at just over scrap price.

Bret L

April 18th 10, 09:08 PM

On Apr 18, 1:50*pm, "Watt? Me worry?" > wrote:
> > On Apr 18, 5:59*pm, Bitchy Loser wrote:
>
> > > *The latest AudioXPress has on its cover a stereo amplifier using one
> > > 4D32 tetrode in Class AB2 per channel as an output device.
>
> > > *Why do people persist in acts that aren't just stupid but willfully destructive?
>
> Hi RATs!
>
> Some people are having a bit of fun, occasionally.
>
> You could never imagine that, but, it happens, anyway.
>
> Almost as if you are not the Supeme Being you assume...

You are being willfully obtuse. These people are destroying other
people's fun for no reason, because the 4D32 is a poor audio tube. It
doesn't work well. If they persist I hope they shock themselves so
badly they have to quit building things for total motor control
failure. Then they will quit being ****ups.

Andre Jute[_2_]

April 18th 10, 11:29 PM

On Apr 18, 7:50*pm, "Watt? Me worry?" > wrote:
> > On Apr 18, 5:59*pm, Bitchy Loser wrote:
>
> > > *The latest AudioXPress has on its cover a stereo amplifier using one
> > > 4D32 tetrode in Class AB2 per channel as an output device.
>
> > > *Why do people persist in acts that aren't just stupid but willfully destructive?
>
> Hi RATs!
>
> Some people are having a bit of fun, occasionally.
>
> You could never imagine that, but, it happens, anyway.
>
> Almost as if you are not the Supeme Being you assume...
>
> Happy Ears!
>
> Al

While there's no accounting for taste, on the other hand: Anyone who
thinks Class AB2 bears any relationship to music deserves to have Bret
Ludwig as his only friend.

Andre Jute
Not everything in materials is dreamt of in Timoshenko

Fred[_12_]

April 19th 10, 03:35 AM

Bret L wrote:
> On Apr 18, 1:50 pm, "Watt? Me worry?" > wrote:
>>> On Apr 18, 5:59 pm, Bitchy Loser wrote:
>>
>>>> The latest AudioXPress has on its cover a stereo amplifier using
>>>> one 4D32 tetrode in Class AB2 per channel as an output device.
>>
>>>> Why do people persist in acts that aren't just stupid but
>>>> willfully destructive?
>>
>> Hi RATs!
>>
>> Some people are having a bit of fun, occasionally.
>>
>> You could never imagine that, but, it happens, anyway.
>>
>> Almost as if you are not the Supeme Being you assume...
>
> You are being willfully obtuse. These people are destroying other
> people's fun for no reason, because the 4D32 is a poor audio tube. It
> doesn't work well. If they persist I hope they shock themselves so
> badly they have to quit building things for total motor control
> failure. Then they will quit being ****ups.

Bret, the difference between you and the average 5 year old is
the 5 year old is way more grown up than you.

John Byrns

April 19th 10, 05:08 AM

In article
>,
Bret L > wrote:

> The latest AudioXPress has on its cover a stereo amplifier using one
> 4D32 tetrode in Class AB2 per channel as an output device.
>
> Why do people persist in acts that aren't just stupid but willfully
> destructive?
>
> The 4D32 was neither designed for nor is it really any good as an
> audio amplifier. Its only use today is as an RF output tube for the
> beautifully built Collins V-line transmitters and a few military field
> transmitters. The supply of these tubes is limited and it is doubtful
> any more will ever be made. No really good substitute exists, although
> the set can be kluged to operate at reduced power and efficiency with
> the VHF twin triodes paralleled together.
>
> Yet we have self centered and ****ish audiophools who persist.
>
> Can you see why I get mad? If the 4D32 were a fantastic audio tube,
> I'd say go ahead and use them up. Make them make more. But it is in
> fact terrible. It sucks as an audio tube.
>
> Even an 811 is far better. Rein Narma made them work just fine.

Hi Bret,

Do you have any idea how audioXpress was able to build an amplifier
using only a single tetrode per channel operating in class AB2? Class
A2 I can understand, but class AB2 only works for audio in push-pull
circuits. If these people have actually built a class AB2 SE amplifier
they certainly aren't audiophiles!

On the other hand it isn't obvious why you say that the 8D32 isn't
"really any good as an audio amplifier"? It looks OK to me, certainly
better than a 811, and it has some interesting characteristics, I may
have to try a design with it, although I would probably go for the 8D22
variation, so you can rest easy.

Regards,

John Byrns

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

Watt? Me worry?

April 19th 10, 05:48 AM

Hi RATs!

The reason a tube sounds good is the circuit it is in, if it ever
sounds good. Not because it was "designed" for low (audio) frequency.

Low frequency is not a huge technological leap, unlike GHz, for
instance.

I am using old TV horizontal amplifiers, 6BQ6, My music is not as
demanding as kicking the electron beam across a CRT.

But, having a ten watt continuous plate rating is a bit less limiting
when the tube is also speced for >500 watts for short periods.

It doesn't matter what the tube was designed to do. If you put it in
an audio circuit and like what you hear, it is an "audio" tube.

No rules for us fools.

If it doesn't work, blame mgmt ;)

Happy Ears!

Al

Bret L

April 19th 10, 06:47 AM

On Apr 18, 11:08*pm, John Byrns > wrote:
> In article
> >,
> *Bret L > wrote:
>
>
>
> > *The latest AudioXPress has on its cover a stereo amplifier using one
> > 4D32 tetrode in Class AB2 per channel as an output device.
>
> > *Why do people persist in acts that aren't just stupid but willfully
> > destructive?
>
> > *The 4D32 was neither designed for nor is it really any good as an
> > audio amplifier. Its only use today is as an RF output tube for the
> > beautifully built Collins V-line transmitters and a few military field
> > transmitters. The supply of these tubes is limited and it is doubtful
> > any more will ever be made. No really good substitute exists, although
> > the set can be kluged to operate at reduced power and efficiency with
> > the VHF twin triodes paralleled together.
>
> > *Yet we have self centered and ****ish audiophools who persist.
>
> > *Can you see why I get mad? If the 4D32 were a fantastic audio tube,
> > I'd say go ahead and use them up. Make them make more. But it is in
> > fact terrible. It sucks as an audio tube.
>
> > *Even an 811 is far better. Rein Narma made them work just fine.
>
> Hi Bret,
>
> Do you have any idea how audioXpress was able to build an amplifier
> using only a single tetrode per channel operating in class AB2? *Class
> A2 I can understand, but class AB2 only works for audio in push-pull
> circuits. *If these people have actually built a class AB2 SE amplifier
> they certainly aren't audiophiles!
>

Busted. I meant to say Class A2.

> On the other hand it isn't obvious why you say that the 8D32 isn't
> "really any good as an audio amplifier"? *It looks OK to me, certainly
> better than a 811, and it has some interesting characteristics, I may
> have to try a design with it, although I would probably go for the 8D22
> variation, so you can rest easy.

Its plate curves are humpty as hell: it isn't linear. It is just
pretty inconveniently configured for its plate rating in terms of
screen requirements, and there is good reason why Collins eschewed it
even for audio (the modulators used 810s for this power range
typically.)

It isn't common or cheap either.

Bret L

April 19th 10, 06:57 AM

On Apr 18, 11:48*pm, "Watt? Me worry?" > wrote:
> Hi RATs!
>
> The reason a tube sounds good is the circuit it is in, if it ever
> sounds good. Not because it was "designed" for low (audio) frequency.
>
> Low frequency is not a huge technological leap, unlike GHz, for
> instance.
>
> I am using old TV horizontal amplifiers, 6BQ6, My music is not as
> demanding as kicking the electron beam across a CRT.
>
> But, having a ten watt continuous plate rating is a bit less limiting
> when the tube is also speced for >500 watts for short periods.
>
> It doesn't matter what the tube was designed to do. If you put it in
> an audio circuit and like what you hear, it is an "audio" tube.
>
> No rules for us fools.
>
They built specific audio, HF RF, VHF/UHF RF, and sweep tubes for
good reason.

Audio types were designed for linearity and to operate their screen
grids at close to the plate supply voltage to make ultralinear
operation feasible.

Some smaller transmitting types are perfectly okay for audio use,
with others it's bad practice when any others are available. The 4D32
is an especially bad choice, plus being rare. The 807 is a decent
choice, as is the 6146 if a separate screen supply is available.
Ultralinear operation of them requires an output transformer with
screen windings.

Sweep tubes are in the same predicament. They are expensive because
the CB keyclowns still run a lot of 11 meter amplifiers with them.

Ian Iveson

April 19th 10, 11:13 AM

*** Al wrote:

Almost as if you are not the Supeme Being you assume...

*** What? But I've just ordered 5000 luminous statues of the
baby Bret...

Watt? Me worry?

April 19th 10, 08:08 PM

Hi RATs!

I did not say tubes were not purposely designed. I said using tubes
for audio that were not designed for audio is neither sinful nor
foolish.

Whatever works, works. It is not as if audio is the highest destiny of
electronics...

nor that it is somehow more noble to send them to the landfill than to
have a listen out of simple curiosity.

Not quite the same thing.

To some of us ;)

Happy Ears!
Al

Patrick Turner

April 20th 10, 06:16 AM

On Apr 19, 6:04*am, Bret L > wrote:
> > At my wesbite I have around 100 odd different types of OPTs for sale
> > at prices similar to the lowest common denominator *prices charged by
> > Hammond Engineering. The OPT mainly have C-cores and plenty of
> > interleaving but the interest from DIYer is almost ZERO.
>
> > In fact the total weight of all the transformers I have for sale is
> > over 1 tonne, and after 18 months I have sold two pairs and used
> > another two pairs in amps I have made for customers. At this rate when
> > I die in 10 months or 10 years there will still be a huge pile of
> > unsold trannys here and they will all go to the re-cyclers for the
> > cppper and iron if nobody buys them, and I strongly doubt anyone ever
> > will, even if I reduced the price by -12dB.
>
> *Last I checked you were wanting considerably more than new Lars
> Lundahl items. Those are a known quantity. I'd buy some if the price
> were right, certainly at just over scrap price.

I think your'e wrong about my pricing, and it depends whach OPT you
want and the wieight and so on. Damned If I could afford to give the
stuff away.
Hammond charge more than I do. I always though Lundahll were more
expensive than Hammond
By the time you add in freight and GST, the cost of what I have is
less than Hammond which has already been shipped here by sea.

I did the research and found Hammond had a certain approximate cost
per Kg, and I went under that. Usually buyers consult me about the
transformer use and the circuit so they get $300 worth of free advice
that both Lundahll and Hammond cannot offer. Most DIYers haven't a
clue what they want, or why.

But then the AUD has climbed a bit.

Patrick Turner.

Patrick Turner

April 20th 10, 06:25 AM

On Apr 19, 8:29*am, Andre Jute > wrote:
> On Apr 18, 7:50*pm, "Watt? Me worry?" > wrote:
>
>
>
>
>
> > > On Apr 18, 5:59*pm, Bitchy Loser wrote:
>
> > > > *The latest AudioXPress has on its cover a stereo amplifier using one
> > > > 4D32 tetrode in Class AB2 per channel as an output device.
>
> > > > *Why do people persist in acts that aren't just stupid but willfully destructive?
>
> > Hi RATs!
>
> > Some people are having a bit of fun, occasionally.
>
> > You could never imagine that, but, it happens, anyway.
>
> > Almost as if you are not the Supeme Being you assume...
>
> > Happy Ears!
>
> > Al
>
> While there's no accounting for taste, on the other hand: Anyone who
> thinks Class AB2 bears any relationship to music deserves to have Bret
> Ludwig as his only friend.

There was a time when anyone with a sense of style wouldn't set foot a
beach without a battery powered radio to acompany they posing. Because
the batteries didn't last too long with high draw, the best audio amps
in the portables has class AB1 or AB2 circuits biased almost for class
B. Nobody complained much and nothing got much better when the
Japanese invented portables for the beach with nearly class B
transistor circuits.

But the early car radios had class A tubes and then class A transistor
amps; just one TO3 transistor with 12V feed and 1 amp idle. Same Pda
as a 6BQ5
Sound was OK.

But I once repaired a Lennard amp with 8 x *L34, Ea = 900V, Eg2 =
450V, and PO = 450W class AB1, and with very little class A. Only
12dB global NFB. It sounded very well in a hall with 300 ppl - much
better than a huge bjt amp.

Patrick Turner.

>
> Andre Jute
> *Not everything in materials is dreamt of in Timoshenko- Hide quoted text -
>
> - Show quoted text -

sparky

April 20th 10, 02:29 PM

On Apr 18, 6:29*pm, Andre Jute > wrote:
> On Apr 18, 7:50*pm, "Watt? Me worry?" > wrote:
>
>
>
>
>
> > > On Apr 18, 5:59*pm, Bitchy Loser wrote:
>
> > > > *The latest AudioXPress has on its cover a stereo amplifier using one
> > > > 4D32 tetrode in Class AB2 per channel as an output device.
>
> > > > *Why do people persist in acts that aren't just stupid but willfully destructive?
>
> > Hi RATs!
>
> > Some people are having a bit of fun, occasionally.
>
> > You could never imagine that, but, it happens, anyway.
>
> > Almost as if you are not the Supeme Being you assume...
>
> > Happy Ears!
>
> > Al
>
> While there's no accounting for taste, on the other hand: Anyone who
> thinks Class AB2 bears any relationship to music deserves to have Bret
> Ludwig as his only friend.
>
> Andre Jute
> *Not everything in materials is dreamt of in Timoshenko- Hide quoted text -
>
> - Show quoted text -

Bret and Andre are conjioned twins with the same disposition.

John Byrns

April 20th 10, 03:36 PM

In article >,
flipper > wrote:

> On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"
> > wrote:
>
> >Hi RATs!
> >
> >I did not say tubes were not purposely designed. I said using tubes
> >for audio that were not designed for audio is neither sinful nor
> >foolish.
>
> Not quite. You said "The reason a tube sounds good is the circuit it
> is in, if it ever sounds good. Not because it was "designed" for low
> (audio) frequency...
> .
> .
> .
> It doesn't matter what the tube was designed to do..."
>
> It most certainly does "matter what the tube was designed to do." A
> remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
> because it was specifically "designed" for a different purpose and, as
> a result, isn't very linear.

Still anyone who has listened to an AM, FM, or even an FM stereo
broadcast in the early years has listened to audio processed through
remote cut off tubes, specifically chosen because of their particular
nonlinearity.

> Now, what's true is that some purposes share similar needs or may, at
> least, be non conflicting. One would, for example, probably like a non
> distorted TV picture and, so, use reasonably linear sweep tubes that
> might also be suitable for audio.

At least in the Horizontal Sweep I didn't think the linearity of the
tube entered into the linearity of the Sweep? My gut feel may be wrong
on this, it's an interesting question, I will have to study up on it.

Regards,

John Byrns

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

Watt? Me worry?

April 20th 10, 04:06 PM

Hi RATs!

Some tubes are fun to put into audio circuits.

Not all.

Some comments aid understanding.

"Most certainly" not "quite" all.

Happy Ears!

Al

Bret L

April 21st 10, 01:46 AM

On Apr 20, 12:16*am, Patrick Turner > wrote:
> On Apr 19, 6:04*am, Bret L > wrote:
>
>
>
> > > At my wesbite I have around 100 odd different types of OPTs for sale
> > > at prices similar to the lowest common denominator *prices charged by
> > > Hammond Engineering. The OPT mainly have C-cores and plenty of
> > > interleaving but the interest from DIYer is almost ZERO.
>
> > > In fact the total weight of all the transformers I have for sale is
> > > over 1 tonne, and after 18 months I have sold two pairs and used
> > > another two pairs in amps I have made for customers. At this rate when
> > > I die in 10 months or 10 years there will still be a huge pile of
> > > unsold trannys here and they will all go to the re-cyclers for the
> > > cppper and iron if nobody buys them, and I strongly doubt anyone ever
> > > will, even if I reduced the price by -12dB.
>
> > *Last I checked you were wanting considerably more than new Lars
> > Lundahl items. Those are a known quantity. I'd buy some if the price
> > were right, certainly at just over scrap price.
>
> I think your'e wrong about my pricing, and it depends whach OPT you
> want and the wieight and so on. Damned If I could afford to give the
> stuff away.
> Hammond charge more than I do. I always though Lundahll were more
> expensive than Hammond
> By the time you add in freight and GST, the cost of what I have is
> less than Hammond which has already been shipped here by sea.

But most of the potential market is abroad so it has to be shipped
the other way. If you included shipping it might be attractive for US
or European customers.

The other problem s you have a lot of different pairs of two each
instead of a big bunch of the same. usually MOST DIYers want a known
design that appeals to them and then buy the transformers that fit it.
Sad to say there are US vendors selling a couple of hundred Dyna ST70
copies a year each because people actually use them in new builds even
though they stink. Of course are replacement for existing ST70s too.
If you had a lot of one you could build one unit around it, advertise
it for a huge sum, then people would build clones of it and feel their
sense of larceny satisfied.

If you advertised "These will fit________" (insert establisnhed unit
like marantz 9, VTL, ARC, what have you) this would help provided this
was actually true.

Bret L

April 21st 10, 01:47 AM

On Apr 20, 10:06*am, "Watt? Me worry?" > wrote:
> Hi RATs!
>
> Some tubes are fun to put into audio circuits.
>
> Not all.
>

The 4D32, to any normal and sane person falls into the second
category pretty clearly.

Bret L

April 21st 10, 01:48 AM

>> " Note: The author of this mesage requested that it not be arched. This message will be remed from Groups in 5 days (Apr 26, 6:53 pm).

On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"

> wrote:
>Hi RATs!

>I did not say tubes were not purposely designed. I said using tubes
>for audio that were not designed for audio is neither sinful nor
>foolish.

Not quite. You said "The reason a tube sounds good is the circuit it
is in, if it ever sounds good. Not because it was "designed" for low
(audio) frequency...
..
..
..
It doesn't matter what the tube was designed to do..."

It most certainly does "matter what the tube was designed to do." A
remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
because it was specifically "designed" for a different purpose and, as
a result, isn't very linear.

Now, what's true is that some purposes share similar needs or may, at
least, be non conflicting. One would, for example, probably like a non
distorted TV picture and, so, use reasonably linear sweep tubes that
might also be suitable for audio.

The previously mentioned 807 is simply the guts of a 6L6 repackaged to
make it even more suitable for RF but that does not negate the audio
characteristics (or vice versa); a case of 'non conflicting'. The guts
were also used for the 6BG6 sweep tube.

You create a straw man in saying "Not because it was "designed" for
low (audio) frequency." "Low frequency" isn't the 'design' criteria.
Linearity, noise, hum, etc. are some of them.

>Whatever works, works. It is not as if audio is the highest destiny of
>electronics...

It also isn't quite as trivial as you imply if your goal is more than
to simply make noise. "<<

Bret L

April 21st 10, 01:52 AM

On Apr 20, 9:36*am, John Byrns > wrote:
> In article >,
>
>
>
> *flipper > wrote:
> > On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"
> > > wrote:
>
> > >Hi RATs!
>
> > >I did not say tubes were not purposely designed. I said using tubes
> > >for audio that were not designed for audio is neither sinful nor
> > >foolish.
>
> > Not quite. You said "The reason a tube sounds good is the circuit it
> > is in, if it ever sounds good. Not because it was "designed" for low
> > (audio) frequency...
> > .
> > .
> > .
> > It doesn't matter what the tube was designed to do..."
>
> > It most certainly does "matter what the tube was designed to do." A
> > remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
> > because it was specifically "designed" for a different purpose and, as
> > a result, isn't very linear.
>
> Still anyone who has listened to an AM, FM, or even an FM stereo
> broadcast in the early years has listened to audio processed through
> remote cut off tubes, specifically chosen because of their particular
> nonlinearity.

You presumably are talking about the use of these tubes in the
receivers, they were used in the RF sections ahead of the
discriminator and did not affect linearity of the demod signal.

They were also used in certain broadcast limiters in the audio chain
as gain controllers. This is a most interesting application and the
surviving such units are worth insane sums to working record cutting
facilities, e.g. the Fairchild 670.

John Byrns

April 21st 10, 03:41 PM

In article
>,
Bret L > wrote:

> On Apr 20, 9:36*am, John Byrns > wrote:
> > In article >,
> >
> >
> >
> > *flipper > wrote:
> > > On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"
> > > > wrote:
> >
> > > >Hi RATs!
> >
> > > >I did not say tubes were not purposely designed. I said using tubes
> > > >for audio that were not designed for audio is neither sinful nor
> > > >foolish.
> >
> > > Not quite. You said "The reason a tube sounds good is the circuit it
> > > is in, if it ever sounds good. Not because it was "designed" for low
> > > (audio) frequency...
> > > .
> > > .
> > > .
> > > It doesn't matter what the tube was designed to do..."
> >
> > > It most certainly does "matter what the tube was designed to do." A
> > > remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
> > > because it was specifically "designed" for a different purpose and, as
> > > a result, isn't very linear.
> >
> > Still anyone who has listened to an AM, FM, or even an FM stereo
> > broadcast in the early years has listened to audio processed through
> > remote cut off tubes, specifically chosen because of their particular
> > nonlinearity.
>
> You presumably are talking about the use of these tubes in the
> receivers, they were used in the RF sections ahead of the
> discriminator and did not affect linearity of the demod signal.

No, these are RF not the audio applications I was referring to.

> They were also used in certain broadcast limiters in the audio chain
> as gain controllers. This is a most interesting application and the
> surviving such units are worth insane sums to working record cutting
> facilities, e.g. the Fairchild 670.

Yes, this is what I was talking about, before solid state became the
norm virtually all broadcast limiters and compressors use remote cutoff
tubes as the gain control elements. Western Electric, RCA, Gates, and
others all built such products using remote cutoff tubes.

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

John Byrns

April 21st 10, 03:45 PM

In article
>,
Bret L > wrote:

> On Apr 20, 10:06*am, "Watt? Me worry?" > wrote:
> > Hi RATs!
> >
> > Some tubes are fun to put into audio circuits.
> >
> > Not all.
> >
>
> The 4D32, to any normal and sane person falls into the second
> category pretty clearly.

What exactly puts the 4D32 into the second category? It looks to me
like it would be fun to put into an audio circuit, and the writer of the
audioXpress article presumably felt the same.

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

Bret L

April 21st 10, 10:49 PM

On Apr 21, 9:41*am, John Byrns > wrote:
> In article
> >,
> *Bret L > wrote:
>
>
>
> > On Apr 20, 9:36*am, John Byrns > wrote:
> > > In article >,
>
> > > *flipper > wrote:
> > > > On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"
> > > > > wrote:
>
> > > > >Hi RATs!
>
> > > > >I did not say tubes were not purposely designed. I said using tubes
> > > > >for audio that were not designed for audio is neither sinful nor
> > > > >foolish.
>
> > > > Not quite. You said "The reason a tube sounds good is the circuit it
> > > > is in, if it ever sounds good. Not because it was "designed" for low
> > > > (audio) frequency...
> > > > .
> > > > .
> > > > .
> > > > It doesn't matter what the tube was designed to do..."
>
> > > > It most certainly does "matter what the tube was designed to do." A
> > > > remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
> > > > because it was specifically "designed" for a different purpose and, as
> > > > a result, isn't very linear.
>
> > > Still anyone who has listened to an AM, FM, or even an FM stereo
> > > broadcast in the early years has listened to audio processed through
> > > remote cut off tubes, specifically chosen because of their particular
> > > nonlinearity.
>
> > *You presumably are talking about the use of these tubes in the
> > receivers, they were used in the RF sections ahead of the
> > discriminator and did not affect linearity of the demod signal.
>
> No, these are RF not the audio applications I was referring to.
>
> > *They were also used in certain broadcast limiters in the audio chain
> > as gain controllers. This is a most interesting application and the
> > surviving such units are worth insane sums to working record cutting
> > facilities, e.g. the Fairchild 670.
>
> Yes, this is what I was talking about, before solid state became the
> norm virtually all broadcast limiters and compressors use remote cutoff
> tubes as the gain control elements. *Western Electric, RCA, Gates, and
> others all built such products using remote cutoff tubes.

The photocell type (Teletronix) was more common: although the 670
wasn't hugely rare it was in the minority. The Gates Level Devil used
these but isn't particularly good.

John Byrns

April 22nd 10, 03:38 AM

In article
>,
Bret L > wrote:

> On Apr 21, 9:41*am, John Byrns > wrote:
> > In article
> > >,
> > *Bret L > wrote:
> >
> >
> >
> > > On Apr 20, 9:36*am, John Byrns > wrote:
> > > > In article >,
> >
> > > > *flipper > wrote:
> > > > > On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"
> > > > > > wrote:
> >
> > > > > >Hi RATs!
> >
> > > > > >I did not say tubes were not purposely designed. I said using tubes
> > > > > >for audio that were not designed for audio is neither sinful nor
> > > > > >foolish.
> >
> > > > > Not quite. You said "The reason a tube sounds good is the circuit it
> > > > > is in, if it ever sounds good. Not because it was "designed" for low
> > > > > (audio) frequency...
> > > > > .
> > > > > .
> > > > > .
> > > > > It doesn't matter what the tube was designed to do..."
> >
> > > > > It most certainly does "matter what the tube was designed to do." A
> > > > > remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
> > > > > because it was specifically "designed" for a different purpose and, as
> > > > > a result, isn't very linear.
> >
> > > > Still anyone who has listened to an AM, FM, or even an FM stereo
> > > > broadcast in the early years has listened to audio processed through
> > > > remote cut off tubes, specifically chosen because of their particular
> > > > nonlinearity.
> >
> > > *You presumably are talking about the use of these tubes in the
> > > receivers, they were used in the RF sections ahead of the
> > > discriminator and did not affect linearity of the demod signal.
> >
> > No, these are RF not the audio applications I was referring to.
> >
> > > *They were also used in certain broadcast limiters in the audio chain
> > > as gain controllers. This is a most interesting application and the
> > > surviving such units are worth insane sums to working record cutting
> > > facilities, e.g. the Fairchild 670.
> >
> > Yes, this is what I was talking about, before solid state became the
> > norm virtually all broadcast limiters and compressors use remote cutoff
> > tubes as the gain control elements. *Western Electric, RCA, Gates, and
> > others all built such products using remote cutoff tubes.
>
> The photocell type (Teletronix) was more common: although the 670
> wasn't hugely rare it was in the minority. The Gates Level Devil used
> these but isn't particularly good.

This is an odd blind spot for you Bret, I suggest you check your 40s and
50s era history again, by far the vast majority of broadcast limiters
from that period used remote cutoff tubes as the gain control elements.

Regards,

John Byrns

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

Bret L

April 22nd 10, 11:54 PM

> > > Yes, this is what I was talking about, before solid state became the
> > > norm virtually all broadcast limiters and compressors use remote cutoff
> > > tubes as the gain control elements. Western Electric, RCA, Gates, and
> > > others all built such products using remote cutoff tubes.
>
> > The photocell type (Teletronix) was more common: although the 670
> > wasn't hugely rare it was in the minority. The Gates Level Devil used
> > these but isn't particularly good.
>
> This is an odd blind spot for you Bret, I suggest you check your 40s and
> 50s era history again, by far the vast majority of broadcast limiters
> from that period used remote cutoff tubes as the gain control elements.

Oh, a lot of them were used, but most worked poorly and the FCC was
more understanding of occasional peak overmod in those days. Plus the
engineers were expected to ride gain. The Teletronix was the first
that worked WELL. The later vari-mu boxes did as well (eg the 670) but
the Level Devil was nt.wth.sht.

They came out when the combo operator became the norm. They were too
busy to ride gain like the union guys.

So technically you are correct but functionally must be qualified. I
should have been more specific.

Incidentally the old Level Devil is in some demand, as an effect more
than anything else. It sounds nice for acoustic guitar and Latin
percussion.

MarkS

April 24th 10, 02:49 AM

"John Byrns" > wrote in message
...
> In article
> >,
> Bret L > wrote:
>
>> On Apr 21, 9:41 am, John Byrns > wrote:
>> > In article
>> > >,
>> > Bret L > wrote:
>> >
>> >
>> >
>> > > On Apr 20, 9:36 am, John Byrns > wrote:
>> > > > In article >,
>> >
>> > > > flipper > wrote:
>> > > > > On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"
>> > > > > > wrote:
>> >
>> > > > > >Hi RATs!
>> >
>> > > > > >I did not say tubes were not purposely designed. I said using
>> > > > > >tubes
>> > > > > >for audio that were not designed for audio is neither sinful nor
>> > > > > >foolish.
>> >
>> > > > > Not quite. You said "The reason a tube sounds good is the circuit
>> > > > > it
>> > > > > is in, if it ever sounds good. Not because it was "designed" for
>> > > > > low
>> > > > > (audio) frequency...
>> > > > > .
>> > > > > .
>> > > > > .
>> > > > > It doesn't matter what the tube was designed to do..."
>> >
>> > > > > It most certainly does "matter what the tube was designed to do."
>> > > > > A
>> > > > > remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
>> > > > > because it was specifically "designed" for a different purpose
>> > > > > and, as
>> > > > > a result, isn't very linear.
>> >
>> > > > Still anyone who has listened to an AM, FM, or even an FM stereo
>> > > > broadcast in the early years has listened to audio processed
>> > > > through
>> > > > remote cut off tubes, specifically chosen because of their
>> > > > particular
>> > > > nonlinearity.
>> >
>> > > You presumably are talking about the use of these tubes in the
>> > > receivers, they were used in the RF sections ahead of the
>> > > discriminator and did not affect linearity of the demod signal.
>> >
>> > No, these are RF not the audio applications I was referring to.
>> >
>> > > They were also used in certain broadcast limiters in the audio chain
>> > > as gain controllers. This is a most interesting application and the
>> > > surviving such units are worth insane sums to working record cutting
>> > > facilities, e.g. the Fairchild 670.
>> >
>> > Yes, this is what I was talking about, before solid state became the
>> > norm virtually all broadcast limiters and compressors use remote cutoff
>> > tubes as the gain control elements. Western Electric, RCA, Gates, and
>> > others all built such products using remote cutoff tubes.
>>
>> The photocell type (Teletronix) was more common: although the 670
>> wasn't hugely rare it was in the minority. The Gates Level Devil used
>> these but isn't particularly good.
>
> This is an odd blind spot for you Bret, I suggest you check your 40s and
> 50s era history again, by far the vast majority of broadcast limiters
> from that period used remote cutoff tubes as the gain control elements.
>
> Regards,
>
> John Byrns
>
> --
> Regards,
>
> John Byrns
>
> Surf my web pages at, http://fmamradios.com/

My old college radio station was essentially a complete RCA AM station from
the mixer boards to the Tx that was donated by a local AM radio station. I
do believe its limiter used 6SK7's.

Mark

John Byrns

April 24th 10, 07:17 PM

In article >,
"MarkS" > wrote:

> "John Byrns" > wrote in message
> ...
> > In article
> > >,
> > Bret L > wrote:
> >
> >> On Apr 21, 9:41 am, John Byrns > wrote:
> >> > In article
> >> > >,
> >> > Bret L > wrote:
> >> >
> >> >
> >> >
> >> > > On Apr 20, 9:36 am, John Byrns > wrote:
> >> > > > In article >,
> >> >
> >> > > > flipper > wrote:
> >> > > > > On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?"
> >> > > > > > wrote:
> >> >
> >> > > > > >Hi RATs!
> >> >
> >> > > > > >I did not say tubes were not purposely designed. I said using
> >> > > > > >tubes
> >> > > > > >for audio that were not designed for audio is neither sinful nor
> >> > > > > >foolish.
> >> >
> >> > > > > Not quite. You said "The reason a tube sounds good is the circuit
> >> > > > > it
> >> > > > > is in, if it ever sounds good. Not because it was "designed" for
> >> > > > > low
> >> > > > > (audio) frequency...
> >> > > > > .
> >> > > > > .
> >> > > > > .
> >> > > > > It doesn't matter what the tube was designed to do..."
> >> >
> >> > > > > It most certainly does "matter what the tube was designed to do."
> >> > > > > A
> >> > > > > remote cutoff pentode, for example, is a lousy choice for 'hi-fi'
> >> > > > > because it was specifically "designed" for a different purpose
> >> > > > > and, as
> >> > > > > a result, isn't very linear.
> >> >
> >> > > > Still anyone who has listened to an AM, FM, or even an FM stereo
> >> > > > broadcast in the early years has listened to audio processed
> >> > > > through
> >> > > > remote cut off tubes, specifically chosen because of their
> >> > > > particular
> >> > > > nonlinearity.
> >> >
> >> > > You presumably are talking about the use of these tubes in the
> >> > > receivers, they were used in the RF sections ahead of the
> >> > > discriminator and did not affect linearity of the demod signal.
> >> >
> >> > No, these are RF not the audio applications I was referring to.
> >> >
> >> > > They were also used in certain broadcast limiters in the audio chain
> >> > > as gain controllers. This is a most interesting application and the
> >> > > surviving such units are worth insane sums to working record cutting
> >> > > facilities, e.g. the Fairchild 670.
> >> >
> >> > Yes, this is what I was talking about, before solid state became the
> >> > norm virtually all broadcast limiters and compressors use remote cutoff
> >> > tubes as the gain control elements. Western Electric, RCA, Gates, and
> >> > others all built such products using remote cutoff tubes.
> >>
> >> The photocell type (Teletronix) was more common: although the 670
> >> wasn't hugely rare it was in the minority. The Gates Level Devil used
> >> these but isn't particularly good.
> >
> > This is an odd blind spot for you Bret, I suggest you check your 40s and
> > 50s era history again, by far the vast majority of broadcast limiters
> > from that period used remote cutoff tubes as the gain control elements.
>
> My old college radio station was essentially a complete RCA AM station from
> the mixer boards to the Tx that was donated by a local AM radio station. I
> do believe its limiter used 6SK7's.

Precisely.

--
Regards,

John Byrns

Surf my web pages at, http://fmamradios.com/

DrRick

May 6th 10, 09:19 PM

Class AB2? With a single output tube? How did the designer accomplish that? I will pick up a copy of the magazine if Barnes & Noble has it.

Class A2 I can understand, but I am unaware of any design methodology in which one could achieve class AB2 (or B) operation with a single output device.

Peace,
DrRick

The latest AudioXPress has on its cover a stereo amplifier using one
4D32 tetrode in Class AB2 per channel as an output device.

Why do people persist in acts that aren't just stupid but willfully
destructive?

The 4D32 was neither designed for nor is it really any good as an
audio amplifier. Its only use today is .........................

Patrick Turner

May 7th 10, 09:55 AM

On May 7, 6:19*am, DrRick > wrote:
> Class AB2? With a single output tube? How did the designer accomplish
> that? I will pick up a copy of the magazine if Barnes & Noble has it.
>
> Class A2 I can understand, but I am unaware of any design methodology
> in which one could achieve class AB2 (or B) operation with a single
> output device.
>
> Peace,
> DrRick
>
> Bret L;906635 Wrote:
>
> > The latest AudioXPress has on its cover a stereo amplifier using one
> > 4D32 tetrode in Class AB2 per channel as an output device.
>
> > Why do people persist in acts that aren't just stupid but willfully
> > destructive?
>
> > The 4D32 was neither designed for nor is it really any good as an
> > audio amplifier. Its only use today is .........................
>
> --
> DrRick

You need TWO tubes for class AB because the term class AB infers that
one tube of the pair cuts off during each wave cycle before the other
tube reaches a crest in the peak tube current when working at power
near clipping.

The data for 4D32 is at http://www.mif.pg.gda.pl/homepages/frank/sheets/138/4/4D22.pdf

Its a grunty tube with Pda rated at 47W, and with RLa-a = 3k, you get
112W in class AB1 using two in PP.

I recall AudioXpress had a class A2 SE amp desogn some years back
using one lone 6550.

Patrick Turner.

John L Stewart

May 22nd 11, 02:45 AM

The real GARY

March 13th 13, 04:53 PM