[Patrick Turner]

Who has the exact winding details for Quad ESL57 and ESL63 audio
transformers?

Patrick Turner.

[Alan Rutlidge]

"Patrick Turner" wrote in message
...
Who has the exact winding details for Quad ESL57 and ESL63 audio
transformers?

Patrick Turner.


You could telephone your "little mate" in Summer Hill or maybe he'll call
you. :P
Sorry Patrick - couldn't resist getting that one in. We all know how
sensitive the little boi is about his precious Quad ESLs. :P
AFAIK there is a John ???? in Melbourne who is a bit of a Quad ESL expert
apparently. Do a Google Groups search - should reveal some useful info on
his full name. Otherwise you might have to call YKW and ask for details.:-(

Cheers,
Alan

[Prune]

Have you considered driving them direct? TV horizontal sweep tubes and
transistors should handle the voltage.


Patrick Turner wrote in news:44BB487F.CA1A1437
@turneraudio.com.au:

Who has the exact winding details for Quad ESL57 and ESL63 audio
transformers?

Patrick Turner.

[Patrick Turner]

Prune wrote:

Have you considered driving them direct? TV horizontal sweep tubes and
transistors should handle the voltage.

Patrick Turner wrote in news:44BB487F.CA1A1437
@turneraudio.com.au:

Who has the exact winding details for Quad ESL57 and ESL63 audio
transformers?

Patrick Turner.


I made the original enquiry on behalf of a repairist who had a pair of these
speakers
which had had their transformers butchered by a DIY owner who was so dumb he
tried to rewind
the transformers without checking if the panels were faulty, which was found
to be the case when the repairist
examined them. The transformers have to be wound just right or else they
just won't give the correct response.

The owner and repairist are totally uninterested in direct drive,
and afaik, sweep tubes and HV transistors would not be so good and methinks
perhaps a 211/845
PP amp or such like would be needed with a 1,500V supply.

Patrick Turner.

[Prune]

Patrick Turner wrote in
:
PP amp or such like would be needed with a 1,500V supply.

More like 2 kV from what I've read DIYers tried (given a 5 kV membrane
bias). Perfect reason to junk an old ham radio for parts ^_^

Instead of push-pull, why not a fully balanced amp with each stator being
driven single endedly?

I guess I've a thing against output transformers (unless it's not working
at audio frequencies, such as the Berning switch-mode/ferrite output
transformer; I know one guy at diyaudio built a 4-phase version and said
it's the closest thing to OTL driving high-impedance speakers he's heard).

[Phil Allison]

"Prune"

Have you considered driving them direct?


** Pure idiocy.

For someone who uses the handle "prune" - he sure has not eaten too many.

Or he would not be so full of ****.





........ Phil

[Prune]

"Phil Allison" wrote in
:
** Pure idiocy.

Why? What's wrong with direct drive? Actually, let me rephrase that: why
do you insist on having a distorting device otherwise known as an output
transformer in your signal path? Last time I looked, transmitter tubes
easily handle the voltage and power required. Tubes are high voltage, and
ESLs are high voltage. Direct drive here is the perfect combination.

[Phil Allison]

"Prune"

" Have you considered driving them direct? TV horizontal sweep tubes and
transistors should handle the voltage."

** Pure idiocy.

Why?


** Cos only an IDIOT would suggests it.


What's wrong with direct drive?


** Its completely stupid.


Actually, let me rephrase that: why
do you insist on having a distorting device otherwise known as an output
transformer in your signal path?


** Massive fallacy.

The Quad ESL input transformers generate no perceptible distortion.


Last time I looked, transmitter tubes
easily handle the voltage and power required.


** Not nearly so well or cheaply or *completely maintenance free* as a good
transformer.

You are a clueless fool.


Tubes are high voltage, and ESLs are high voltage.

Direct drive here is the perfect combination.


** What ** Complete **********.





......... Phil

[Prune]

"Andre Jute" wrote in
ups.com:
I don't think so. We worked it out on the Joenet once and 2000V
*operating* plate voltage (probably 2300-2500V power trx required
after allowing for the various drops and bias etc) was generally
agreed to be a minimum.

Wouldn't a 3-500Z per stator (so single-ended differential drive of the
whole speaker) do the job? The tubes certainly are usable for audio, as
there was a website where someone used them to drive dynamic speakers
through an output transformer.

For smaller speakers maybe even 4CX250B would be enough (2 kV max), or as
you mentioned, paralleled smaller tubes (I think some TV tubes have the
rating, though ones I've seen rarely go above 1.5 kV).

Frankly, I think direct drive of expensive and irreplacable panels is
daft. Even driving new panels directly seems to me a bit obsessive. I
like the isolation of various transformers.

No doubt it's safer. I guess transformers just never sound good to some
people (I'm sure I'm not the only one).

[Prune]

"Phil Allison" wrote in
:
The Quad ESL input transformers generate no perceptible distortion.

I'd love to see the blind test comparing with a direct drive amplifier that
demonstrated that conclusion (otherwise, you are pulling it out of you know
where).

[Phil Allison]

"Prune" = Another Absolute ****wit.


The Quad ESL input transformers generate no perceptible distortion.

I'd love to see the blind test comparing with a direct drive amplifier
that
demonstrated that conclusion (otherwise, you are pulling it out of you
know
where).


** How utterly asinine.

No such silly test is needed (or even possible) to establish a simple
fact.

A properly made transformer is an inherently *very linear* device.


OTOH , YOU are KNOW NOTHING ****ing half-wit.





........ Phil

[Patrick Turner]

Prune wrote:

Patrick Turner wrote in
:
PP amp or such like would be needed with a 1,500V supply.

More like 2 kV from what I've read DIYers tried (given a 5 kV membrane
bias). Perfect reason to junk an old ham radio for parts ^_^

Instead of push-pull, why not a fully balanced amp with each stator being
driven single endedly?

I guess I've a thing against output transformers (unless it's not working
at audio frequencies, such as the Berning switch-mode/ferrite output
transformer; I know one guy at diyaudio built a 4-phase version and said
it's the closest thing to OTL driving high-impedance speakers he's heard).

Tubes work best with OPT, and the ESL step up trannys don't degrade the sound.

Patrick Turner.

[Patrick Turner]

Prune wrote:

"Phil Allison" wrote in
:
** Pure idiocy.

Why? What's wrong with direct drive? Actually, let me rephrase that: why
do you insist on having a distorting device otherwise known as an output
transformer in your signal path? Last time I looked, transmitter tubes
easily handle the voltage and power required. Tubes are high voltage, and
ESLs are high voltage. Direct drive here is the perfect combination.

There are safety reasons for not using direct drive.
Cables carrying several thousand lethal volts from amp to speakers
isn't such a great idea. Kiddies crawling on the carpet place a cable in their
mouth.
There is a small crack in the insulation.......... yeow!
Lawyers will have a field day.

Purely from the technical perpective, direct drive looks OK, even using
a standard KT88 PP amp with a 1:5 OPT step up tranny off the plate circuit
would be better than stepping down 20 times, then back up 100 times in the
ESL.
But Peter Walker proved direct drive provided no special sonic benefits.....

Patrick Turner.

[Patrick Turner]

Prune wrote:

"Phil Allison" wrote in
:
The Quad ESL input transformers generate no perceptible distortion.

I'd love to see the blind test comparing with a direct drive amplifier that
demonstrated that conclusion (otherwise, you are pulling it out of you know
where).

The direct drive from a PP pair of 845 tubes would have much more distortion
than
the use of normal amp with NFB.

Its a tantalizing idea, direct drive to ESL, but one that isn't necessary for
excellent sound.
Transformer coupling generates an order of magnitude less distortion than the
tubes used
in any amp. And this is so even in a humble Quad II amp. An its NFB reduces the
tranny distortions....

Patrick Turner.

[Prune]

Patrick Turner wrote in
:
The direct drive from a PP pair of 845 tubes would have much more
distortion than
the use of normal amp with NFB.

You can easily have NFB in a direct drive amp. This electrostatic
headphone amplifier has plenty of NFB, and 1500 V differential output with
0.004% THD:

http://www.headwize.com/projects/sho...lmore4_prj.htm

The nonlinearity of the P-channel followers driving the cathodes are
approximately inverse to that of the tubes, so even before feedback there's
not that much distortion. With NFB you get some reduction, the symmetry
gives you more with matched devices, and you get another type of distortion
reduction since some of the feedback goes to the other side in phase
(through the LTP sources coupling) to end up as common mode error on the
output (even if I change voltages so that one side clips, then the other
side of the output makes up for this so that the differential output is
still what it should be). Sure, it's just headphones, but I see it as
proof of concept that direct drive is practical and can achieve arbitrarily
low distortion.

[Phil Allison]

"Prune"

Sure, it's just headphones, but I see it as
proof of concept that direct drive is practical and can achieve
arbitrarily
low distortion.


** What a load of old ********.

Reality check:

The Quad ESL57 input transformer has an overall turns ratio of 292:1.

The bias voltage on the bass panels is 6.2kV and they require 18 kV volts
p-p of audio to reach full output.

The bias voltage on the mid/high panel is 1.5 kV and requires 6 kV p-p of
audio to reach full output.

The Quad ESL63 has a bias voltage of 5.2 kV on the panels and requires 16 kV
p-p of audio to reach full output.


To achieve this feat:

The ESL57 uses a single, modest size, C-core transformer to provide the two
levels of audio drive.

The ESL63 uses a pair of modest size, C- core transformers to provide the
audio drive.






........ Phil

[Prune]

"Phil Allison" wrote in
:
The bias voltage on the bass panels is 6.2kV and they require 18 kV
volts p-p of audio to reach full output.

A 715B is dirt cheap and easily handles 15 kV. Don't even need forced air
cooling as it's a standard glass tube. As for X-rays, a 15 kV accelerating
potential generates very soft X-rays and a few cm of air is shielding
enough.

[Phil Allison]

"Prune"

** Idiot.






........ Phil

[Prune]

"Phil Allison" wrote in news:4idse8F3b3nuU1
@individual.net:


"Prune"

** Idiot.

You misspelled your name.

[Patrick Turner]

Prune wrote:

"Phil Allison" wrote in news:4idse8F3b3nuU1
@individual.net:


"Prune"

** Idiot.

You misspelled your name.

But Phil is pointing out the actual voltages involved with direct drive
of
ESL. Divide 18kV pk-pk by 2.82 and you get the Vrms a-a needed from a PP
tube amp.
About 6,000 Vrms capability is required.
The transformer option remains the cheapest and most easily effective.
Even with tubes like 845/211, you's still need a step up tranny.

But don't let us stop you from demonstrating how much better direct
drive sounds
by assembling something yourself.

We leave you to find out your own truth.

Meanwhile, I still have no winding details for the ESL 63 transformers,
which
was what I wanted when i began this subject thread.

Patrick Turner.

[Prune]

Patrick, I mentionied a standard glass tube that handles 15 kV easily in
this very same thread: 715B

I don't know why you insist on push-pull. You can drive each stator
single-ended by the opposing sides of a differential amplifier. One
stator is pushing when the other is pulling, then reverse (or maybe
that's what you meant, instead of the output stage to one stator being
push-pull).

As for testing my theory, my listening experience is limited to
electrostatic headphones. I've listened to various of the Stax
offerings from the $50 ancient ones on eBay to the $2000 Omega 2s, with
many different amps, and I can tell you that there's a reason all amps
now Stax makes for its headphones are direct drive, as they most
certainly sound better than any of the transformer-coupled amps they
used to build in the decades past. Unless transformer technology has
improved enormously in the past decade or so, the choice for me is
clear. Sure, the headphones are at full blast with a mere 800 V peak to
peak, but there are reasonably easy tubes to drive at low-double digits
kV, such as the one example I already mentioned. And even the ceramic
transmitter tubes are not hard to deal with if you can find the sockets
cheaply, and quiet cooling option (such as the conductive cooling
solutions that exist for the smaller ones). Probably better than the
danger of a fragile glass tube at that voltage anyway.


Patrick Turner wrote in news:44C1E3AB.F341BFA7
@turneraudio.com.au:



Prune wrote:

"Phil Allison" wrote in news:4idse8F3b3nuU1
@individual.net:


"Prune"

** Idiot.

You misspelled your name.

But Phil is pointing out the actual voltages involved with direct
drive
of
ESL. Divide 18kV pk-pk by 2.82 and you get the Vrms a-a needed from a
PP
tube amp.
About 6,000 Vrms capability is required.
The transformer option remains the cheapest and most easily effective.
Even with tubes like 845/211, you's still need a step up tranny.

But don't let us stop you from demonstrating how much better direct
drive sounds
by assembling something yourself.

We leave you to find out your own truth.

Meanwhile, I still have no winding details for the ESL 63
transformers,
which
was what I wanted when i began this subject thread.

Patrick Turner.

[Tom A.]

Have you considered driving them direct? TV horizontal sweep tubes and
transistors should handle the voltage.

I believe that Acoustat once offered some electrostatic models that
incorporated a direct drive tube power amp. Do I remember correctly?
Anyway, the fact is that no direct drive ESLs are now on the market (as
far as I know), while it seems at first sight a good idea. Thus it is
probably not such a great idea.

regards, Tom

[Sander deWaal]

Tom A. said:


I believe that Acoustat once offered some electrostatic models that
incorporated a direct drive tube power amp. Do I remember correctly?


Yep, they did.
A bunch of silly TV sweep tubes (6LF6 or EL519 or something).
A glowing disaster, a PITA to repair and didn't sound too well to
boot.


Anyway, the fact is that no direct drive ESLs are now on the market (as
far as I know), while it seems at first sight a good idea. Thus it is
probably not such a great idea.


There are several DIY attempst (that I know of) to drive Martin Logan
panels directly with sweep tubes, but again, the problem lies in the
reliabillty.

Good transformers, correctly designed for their task, when used in the
audible range, are as good as transparent.
Anyone mumbling about "transformer distortion" when driving panels,
either used the wrong trannies for this application, or was using them
incorrectly and/or out of spec.

--
"All amps sound alike, but some sound more alike than others".

[Andre Jute]

Sander deWaal wrote:

There are several DIY attempst (that I know of) to drive Martin Logan
panels directly with sweep tubes, but again, the problem lies in the
reliabillty.

Also some solid state designs to drive panels. One that thought about
for a while seemed well-conceived. It was by a guy called Neil, IIRC.

Good transformers, correctly designed for their task, when used in the
audible range, are as good as transparent.
Anyone mumbling about "transformer distortion" when driving panels,
either used the wrong trannies for this application, or was using them
incorrectly and/or out of spec.

Hallelujah.

--
"All amps sound alike, but some sound more alike than others".

Hmm. A "fact" that PinkoStinko and Poopie and the Arniiii all agree on
is somehow suspicious...

Andre Jute
Our legislators managed to criminalize fox-hunting and smoking; when
they will get off their collective fat arse and criminalize negative
feedback? It is clearly consumed only by undesirables.

[Patrick Turner]

Prune wrote:

Patrick, I mentionied a standard glass tube that handles 15 kV easily in
this very same thread: 715B

Maybe a pair of 715B will work in PP tetrode. But trying to run such HV in
leads from amp to speaker
is not user friendly.



I don't know why you insist on push-pull. You can drive each stator
single-ended by the opposing sides of a differential amplifier. One
stator is pushing when the other is pulling, then reverse (or maybe
that's what you meant, instead of the output stage to one stator being
push-pull).

A differential pair isn't a single ended amp; the diff pair or LTP has two
balanced outputs
if loaded by a CT choke or individual resistaors and 2H current cancellation
occurs in the
shared cathode circuit.



As for testing my theory, my listening experience is limited to
electrostatic headphones. I've listened to various of the Stax
offerings from the $50 ancient ones on eBay to the $2000 Omega 2s, with
many different amps, and I can tell you that there's a reason all amps
now Stax makes for its headphones are direct drive, as they most
certainly sound better than any of the transformer-coupled amps they
used to build in the decades past.

I was given a pair of Stax phones and drive unit which I stripped down.
The signal is rectified to generate a lasting charge on the panel. Its a
very simple arrangement.

Unless transformer technology has

improved enormously in the past decade or so, the choice for me is
clear.

Having direct drive is more a gimicky claim rather than technological
progress.
Transfromer design for such applications probably has not progressed much.
It hasn't needed to have progressed because it *is* effective.
The measured difference between direct drive and transformer coupling
is negligible.
Just exactly what is your technical objection to transformer use in ESL?
Please don't tender statements about "it sounds better"; that discussion can
wait until after you
prove transformers suck technically. Be brief in your concise explanations
please.



Sure, the headphones are at full blast with a mere 800 V peak to

peak, but there are reasonably easy tubes to drive at low-double digits
kV, such as the one example I already mentioned.

The 800V p-p is easy enough to insulate well in wiring which is so close to
a users head.

But having perhaps up to 20kV p-p is a different matter.


And even the ceramic
transmitter tubes are not hard to deal with if you can find the sockets
cheaply, and quiet cooling option (such as the conductive cooling
solutions that exist for the smaller ones). Probably better than the
danger of a fragile glass tube at that voltage anyway.

I will pass on this challenge to demonstrate to the world that direct drive
of ESL63
is easy and simple and safe.

Be my guest to prove to us all that direct drive is the way to go.

Patrick Turner.



Patrick Turner wrote in news:44C1E3AB.F341BFA7
@turneraudio.com.au:



Prune wrote:

"Phil Allison" wrote in news:4idse8F3b3nuU1
@individual.net:


"Prune"

** Idiot.

You misspelled your name.

But Phil is pointing out the actual voltages involved with direct
drive
of
ESL. Divide 18kV pk-pk by 2.82 and you get the Vrms a-a needed from a
PP
tube amp.
About 6,000 Vrms capability is required.
The transformer option remains the cheapest and most easily effective.
Even with tubes like 845/211, you's still need a step up tranny.

But don't let us stop you from demonstrating how much better direct
drive sounds
by assembling something yourself.

We leave you to find out your own truth.

Meanwhile, I still have no winding details for the ESL 63
transformers,
which
was what I wanted when i began this subject thread.

Patrick Turner.

[Prune]

"Andre Jute" wrote in news:1153588837.080513.198180@
75g2000cwc.googlegroups.com:
Also some solid state designs to drive panels. One that thought about
for a while seemed well-conceived. It was by a guy called Neil, IIRC.

I'm curious about that. I've yet to find an SS devices that does much
above 1.5 kV, unless it's stacks of them like I've seen in some HV supplies
(and of course when one fries, the whole stack goes).

Andre Jute
Our legislators managed to criminalize fox-hunting and smoking; when
they will get off their collective fat arse and criminalize negative
feedback? It is clearly consumed only by undesirables.

LOL! Still, listening to stuff with limited amount of NFB in an amp that
has sufficient slew rate doesn't sound bad to my ears. But now there are
all sorts of alternatives like predistortion, using devices with inverse
nonlinearities, Hawksford error correction (feed back and/or forward the
error signal only instead of the whole signal), etc., so you can still get
low distortion without it.

[Prune]

Tom A. wrote in news:2006072218453316807-
camembert@eudoramailcom:
Anyway, the fact is that no direct drive ESLs are now on the market (as

The Hill Plasmatronics speakers are also no longer on the market. But as
in the ESL direct drive case, that doesn't say anything about sonics;
rather, it's more about practicality in terms of difficulty of repair,
safety, and corporate liability in case of accidents (the measurements I've
seen of the Plasmatronics had the cleanest waterfall plot I've ever seen of
any tweeter; too bad Philippbar's page with these and other measurements
has been down the last year; unfortunately a glow discharge emitting UV and
capable of vaporizing tungsten wire is out of the question in the current
litiguous times, not to mention the need to refill periodically the helium
tank).

[Patrick Turner]

Prune wrote:

"Andre Jute" wrote in news:1153588837.080513.198180@
75g2000cwc.googlegroups.com:
Also some solid state designs to drive panels. One that thought about
for a while seemed well-conceived. It was by a guy called Neil, IIRC.

I'm curious about that. I've yet to find an SS devices that does much
above 1.5 kV, unless it's stacks of them like I've seen in some HV supplies
(and of course when one fries, the whole stack goes).

Andre Jute
Our legislators managed to criminalize fox-hunting and smoking; when
they will get off their collective fat arse and criminalize negative
feedback? It is clearly consumed only by undesirables.

LOL! Still, listening to stuff with limited amount of NFB in an amp that
has sufficient slew rate doesn't sound bad to my ears. But now there are
all sorts of alternatives like predistortion, using devices with inverse
nonlinearities, Hawksford error correction (feed back and/or forward the
error signal only instead of the whole signal), etc., so you can still get
low distortion without it.

Andre has a joke in his signature.

Inverse non linearities have to be treated with caution although the 2H of a
driver triode voltage signal
usually cancels the 2H in an SET output tube to a useful amount.
But the odd numbered harmonics don't always cancel at all.

But the main reason for NFB is to reduce the output resistance and if the tube
or SS circuit
is working in class A then the maximum NFB needed is 20 dB.

Much more is used and typical NFB in most SS amps is say 40dB in the emitter
follower output stage and
then 50 dB of global making a total of 90 dB. Hence great measurements but no
more music necessarily.

Positive current feedback was also occasionally used in the 1950s to reduce
Rout.
Only about 3dB is needed lest the amp oscillate with a short ciruit or a low
load value, since it is easy to
make an amp with negative Rout, ie, the output voltage rises with falling load
value.
This isn't a good scenario, as theis FB causes an increase in THD and reduction
in bandwidth
like most positive FB.
neg voltage FB can be used in addition to the positive current FB to give both
low THD
wide BW, and extremely low Rout, easily tailored so Rout is nearly negative, ie
a fraction of an ohm
like a high NFB SS amp usually is.

Bogen had variable Rout using adjustable pos. current FB.

Only triodes make decent amps without external loops of NFB.
The lowest Rout in such a case is achieved with a high Z ratio in the OPT.

I don't know why more PP amps with a pair of 300B are not used more often with
say a 10k a-a load for about 20 watts AB1 which is very nice power without loop
NFB.

Patrick Turner.

[Sander deWaal]

Patrick Turner said:


Much more is used and typical NFB in most SS amps is say 40dB in the emitter
follower output stage and
then 50 dB of global making a total of 90 dB. Hence great measurements but no
more music necessarily.


Huh?
You can't add up *local* feedback to *global* feedback!

--
"All amps sound alike, but some sound more alike than others".

[Patrick Turner]

Sander deWaal wrote:

Patrick Turner said:

Much more is used and typical NFB in most SS amps is say 40dB in the emitter
follower output stage and
then 50 dB of global making a total of 90 dB. Hence great measurements but no
more music necessarily.

Huh?
You can't add up *local* feedback to *global* feedback!

I can, and i did.

The total of 90 dB of series voltage nfb exists at the output devices which
generate the dreaded
crossover distortions.
the 40 dB of the local reduces the Xover Dn to less than 0.01% and this is further
reduced by the
global NFB.
So in many SS amps, the crossover distortions are almost unmeasurably low; but the
macro
distortions of mainly 2H, 3H in the class A voltage swing of the VAS is only
reduced by the global.

Even in the input diffpair there is local current emitter follower FB.

Patrick Turner.



--
"All amps sound alike, but some sound more alike than others".

[Prune]

Patrick Turner wrote in
:

I will pass on this challenge to demonstrate to the world that direct
drive of ESL63
is easy and simple and safe.

I actually have a more interestind high voltage load: glow discharge
plasma. I intend to use the small ceramic power beam tetrodes 4X150A. I
figured out how to build speakers based on the technology of the Hill
Plasmatronic speakers without the need for helium.