AudioMisc pages on early J. E. Sugden Class A amps
 

Hi,

Just to let people know that I've now put up some webpages on Jim Sugden's
original Class A solid state power amps. You can find these via a new link
on the AudioMisc page (URL in my sig below). :-)

I will add more pages on JES as and when I get a chance. Next to be added
will be pages on the Hi Fi News 'home constructor' version of the
amplifiers, and pages on the A41/A51 and their control (pre) amps.

Hope people find the pages of interest.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

AudioMisc pages on early J. E. Sugden Class A amps
 

On Tue, 04 Sep 2007 18:47:10 +0100, Jim Lesurf
wrote:

Hi,

Just to let people know that I've now put up some webpages on Jim Sugden's
original Class A solid state power amps. You can find these via a new link
on the AudioMisc page (URL in my sig below). :-)

I will add more pages on JES as and when I get a chance. Next to be added
will be pages on the Hi Fi News 'home constructor' version of the
amplifiers, and pages on the A41/A51 and their control (pre) amps.

Hope people find the pages of interest.

Slainte,

Jim

Definitely, thanks for those. Have to say that the biasing methods
have a very fragile look to them; Sugden definitely had a bee in his
bonnet about how an amplifier should work. Unfortunately for him it
wasn't long after all this that people started to suss how to make a
class B amp without the huge distortion rise at low level.

I'm a little surprised he didn't get as far as a long-tail pair for
the input. The technique was well enough known by then. Perhaps a
component count issue? Transistors cost a fortune back then; I can
remember my 30/- OC71.

d

--
Pearce Consulting
http://www.pearce.uk.com

AudioMisc pages on early J. E. Sugden Class A amps
 

Jim Lesurf wrote:
Hi,

Just to let people know that I've now put up some webpages on Jim Sugden's
original Class A solid state power amps. You can find these via a new link
on the AudioMisc page (URL in my sig below). :-)

I will add more pages on JES as and when I get a chance. Next to be added
will be pages on the Hi Fi News 'home constructor' version of the
amplifiers, and pages on the A41/A51 and their control (pre) amps.

Hope people find the pages of interest.

Slainte,

Jim


Long sold now, but I posted these a while back:

http://patchoulian.googlepages.com/sugdenc51andp51

I've probably got some more photos, should you ever need them.

FWIW they were pretty good, and serviced/repaired by Sugden in 2004.

Rob

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Rob

wrote:


Long sold now, but I posted these a while back:

http://patchoulian.googlepages.com/sugdenc51andp51

I'll have a look later this morning. :-)

I've probably got some more photos, should you ever need them.

You sent me PDF copies of the documents IIRC. However I'd welcome any good
colour photos of the amps. I have a pile of documents the people at Sugden
Audio kindly sent to me. This includes things like Jim Sugden's original
notes, etc. But I lack good colour photos of the early units.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Don Pearce
wrote:
On Tue, 04 Sep 2007 18:47:10 +0100, Jim Lesurf
wrote:

Hi,

Just to let people know that I've now put up some webpages on Jim
Sugden's original Class A solid state power amps. You can find these
via a new link on the AudioMisc page (URL in my sig below). :-)

Definitely, thanks for those. Have to say that the biasing methods have
a very fragile look to them;

Well, it was the mid 1960s and the transistors available at the time were
poor (perhaps a better term would be 'rubbish' compared with nowdays), as
well as people not yet having really learned how to use bipolars in ways
we'd now regard as 'obvious' for giving best results. The bias
stabilisation diodes were a neat trick. These days we'd probable use
something more like a rubber zener, but I don't know when that first came
into use.

I've been told that the need to carefully match the diodes and resistors
into matched sets in boxes was a real PITA. Kept one 'girl' sic working
full time just on that.


Sugden definitely had a bee in his bonnet about how an amplifier should
work. Unfortunately for him it wasn't long after all this that people
started to suss how to make a class B amp without the huge distortion
rise at low level.

Indeed. By about the mid 1970s the early problems had essentially been
sussed. The available power transistors were also much better. As a result
topologies like the 'triples' and the linearised versions of class AB were
in use. JES themselves slowly moved away from Class A into what was either
AB or more like 'high bias' than Class A. In fairness, though, in the days
when a BD121 was the state of the art it would be dubious if these more
familiar arrangements would have worked OK. And although we nowdays take
them as if they appeared in the year dot, they actually had to be invented.
;-

I'm a little surprised he didn't get as far as a long-tail pair for the
input. The technique was well enough known by then. Perhaps a component
count issue? Transistors cost a fortune back then; I can remember my
30/- OC71.

When I get a chance to do the relevant pages, you should find the 'series
3' and later had arrangements that would be more familiar these days. TBH
the thing that makes my hair[1] stand on end with the early JES designs is
the a.c. coupling from one stage to another inside the feedback loop. Alas,
I don't have a circuit for the Si 402 so can only suspect it was similar to
the A21/A41 at present. I can't even determine yet if any were ever sold.
Hence my assumption at present that the Richard Allan amp was the first
Class A SS power amp to go on sale for domestic HiFi.

I found it quite interesting how the designs did evolve as he experimented
and learned. The change was quite rapid during the first couple of years.

I have been told that both Hacker radio and Uncle Clive argued about who
was first. But I've not found any contemporary documents on that as yet.
Found more well-known items by JLH, Williamson, etc, though.

Slainte,

Jim

[1] Not that I have much hair on my head these days to engage in such
reactions. :-)

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

AudioMisc pages on early J. E. Sugden Class A amps
 

"Jim Lesurf" wrote in message
...
Hi,

Just to let people know that I've now put up some webpages on Jim
Sugden's
original Class A solid state power amps. You can find these via a new
link
on the AudioMisc page (URL in my sig below). :-)

I will add more pages on JES as and when I get a chance. Next to be
added
will be pages on the Hi Fi News 'home constructor' version of the
amplifiers, and pages on the A41/A51 and their control (pre) amps.

Hope people find the pages of interest.


Sugden's current adverting slogan appears to be:

"Rescuing music from technology"

:-)

AudioMisc pages on early J. E. Sugden Class A amps
 

"Jim Lesurf"

Just to let people know that I've now put up some webpages on Jim Sugden's
original Class A solid state power amps. You can find these via a new link
on the AudioMisc page (URL in my sig below). :-)

I will add more pages on JES as and when I get a chance. Next to be added
will be pages on the Hi Fi News 'home constructor' version of the
amplifiers, and pages on the A41/A51 and their control (pre) amps.

Hope people find the pages of interest.


** Only if they actually ENJOY reading tedious, pseudo technical drivel.

Your page on the A21 is particularly loaded with fallacies and nonsense.

Gullible readers are being expected to believe that 1968 was some kind of
"dark ages" in SS amplifier history, that the available silicon transistors
were of highly inferior quality and designers were all still struggling with
the evil bogey of crossover distortion.

And that class A operation was the answer.


WHAT ******** !!



Eg:

Quad released their famous 303 model way back in 1967 !!

In 1969 it won a Design Council Award.

The 303 delivered 45 watts per channel into 8 ohms loads.

It was short circuit safe.

It used all silicon transistors and exhibited no sign of crossover
distortion.

The power devices used were rugged planar types, RCA 38494s and 40411s.

THD measured at the 1 watt level was circa 0.003% and less than 0.03 % at
rated power - ten times less at both levels than Sugden's woeful A21.

The 303 used regulated PSU and drove the "difficult" ESL57 with ease.

It ran cool with very low idle current in the output devices.

Compared to the Quad 303, Sugden's A21 was a pile of junk.

It is * NO * surprise that a credible magazine like Wireless World failed
to mention its appearance at some 1968 audio fair.

Since it was clearly an embarrassment !!
---------------------------------------------


BTW:

This French page has some good pics of the insides of a Quad 303.

http://cf.geocities.com/quadfranco/a...33/amp303.html

Here is a schematic of the 1970 version.

http://www.geocities.com/quad_esl63/...c/power303.jpg





......... Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

Quad released their famous 303 model way back in 1967 !!

In 1969 it won a Design Council Award.

The 303 delivered 45 watts per channel into 8 ohms loads.

It was short circuit safe.

It used all silicon transistors and exhibited no sign of crossover
distortion.

The power devices used were rugged planar types, RCA 38494s and 40411s.

THD measured at the 1 watt level was circa 0.003% and less than 0.03 % at
rated power - ten times less at both levels than Sugden's woeful A21.

The 303 used regulated PSU and drove the "difficult" ESL57 with ease.

It ran cool with very low idle current in the output devices.

Compared to the Quad 303, Sugden's A21 was a pile of junk.

It is * NO * surprise that a credible magazine like Wireless World failed
to mention its appearance at some 1968 audio fair.

Since it was clearly an embarrassment !!
---------------------------------------------


BTW:

This French page has some good pics of the insides of a Quad 303.

http://cf.geocities.com/quadfranco/a...33/amp303.html

Here is a schematic of the 1970 version.

http://www.geocities.com/quad_esl63/...c/power303.jpg


Yes thats the better one with the diode-less biasing arrangement. We
used to copy that diagram and made no end of them for mates and other
applications;)

I'm sure PW wouldn't have really minded after all it was spreading the
good word;)

I re-furbed a pair for my wife's study room a couple of years ago, new
uprated power, output, and PCB caps. New cermet pots, beefed up a bit
of the output wiring and its as good, possibly a bit better, than new
and will last many, many years yet:-)........

--
Tony Sayer

AudioMisc pages on early J. E. Sugden Class A amps
 

"tony sayer" wrote in message
...
Quad released their famous 303 model way back in 1967 !!

In 1969 it won a Design Council Award.

The 303 delivered 45 watts per channel into 8 ohms loads.

Performance into 4 ohm loads?

It was short circuit safe.

There are no classic SOA or current limiters. How was the output stage
protected?

It used all silicon transistors and exhibited no sign of crossover
distortion.

Par for the course.

The power devices used were rugged planar types, RCA 38494s and 40411s.

40411s were rugged, indeed.

THD measured at the 1 watt level was circa 0.003% and less than 0.03 % at
rated power - ten times less at both levels than Sugden's woeful A21.

OK, that's at 1 KHz. How about 20 KHz?

The 303 used regulated PSU and drove the "difficult" ESL57 with ease.

It ran cool with very low idle current in the output devices.

Compared to the Quad 303, Sugden's A21 was a pile of junk.

The interest in the Sugden amps mystifies me because they seem to be so
backward.


This French page has some good pics of the insides of a Quad 303.

http://cf.geocities.com/quadfranco/a...33/amp303.html

Here is a schematic of the 1970 version.

http://www.geocities.com/quad_esl63/...c/power303.jpg

It looks to me like there is no loop feedback from the output back to
anyplace near the input. Am I missing something?

Yes thats the better one with the diode-less biasing arrangement. We
used to copy that diagram and made no end of them for mates and other
applications;)

I'm sure PW wouldn't have really minded after all it was spreading the
good word;)

I re-furbed a pair for my wife's study room a couple of years ago, new
uprated power, output, and PCB caps. New cermet pots, beefed up a bit
of the output wiring and its as good, possibly a bit better, than new
and will last many, many years yet:-)........

The contemporaneous similar US amp might have been the Dyna ST-120 which had
a far more checkered reputation.

AudioMisc pages on early J. E. Sugden Class A amps
 

"Arny Krueger"
Phil Allison


** Try answering the right person's post - Arny.

Sayer snipped the original context out of sight and now YOU are asking him
about MY post.

Then you sneakily introduce a NEW context of your own making.

What a posturing ASS you are.



The 303 delivered 45 watts per channel into 8 ohms loads.

Performance into 4 ohm loads?


** Not relevant - ask the same Q about the A21.

( The 303 spec was for 42 watts at 6 ohms. )



It was short circuit safe.

There are no classic SOA or current limiters. How was the output stage
protected?


** The output triples inherently limit at 4.5 amps.


It used all silicon transistors and exhibited no sign of crossover
distortion.

Par for the course.


** Absolutely not the case for domestic SS amps in 1967.

The 303 was non bias critical & output device temp did not affect the
setting.

Go look at the original context for MY post.

Stop being such a PITA smartarse Septic ASSHOLE !!!.



THD measured at the 1 watt level was circa 0.003% and less than 0.03 % at
rated power - ten times less at both levels than Sugden's woeful A21.

OK, that's at 1 KHz. How about 20 KHz?


** The 303 spec was for 0.1 % at any level up to 45 watts at 10kHz.



Compared to the Quad 303, Sugden's A21 was a pile of junk.

The interest in the Sugden amps mystifies me because they seem to be so
backward.


** A quirky, pommy amp only a quirky pommy could love.



Here is a schematic of the 1970 version.

http://www.geocities.com/quad_esl63/...c/power303.jpg


It looks to me like there is no loop feedback from the output back to any
place near the input. Am I missing something?


** You sure have missed it:

R113 (82k) and R 111 (2.2k) divide the output by 38.3 times, then R108 & R
101 ( both 22k) cause the whole amp to act as a unity gain inverter to that
divided down level.

So overall gain is - 38.3 and the input sensitivity = 500mV.


Hey Arny - still not corrected all those STUPID errors on your page about
the Crown amp ?

****ing compewter geek ******.




........ Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

"Phil Allison"

http://www.geocities.com/quad_esl63/...c/power303.jpg

** The output triples inherently limit at 4.5 amps.


** Silicon diodes MR105 & MR106 (along with TR7, the 1.4 volt Vbe
multiplier used for bias setting ) are responsible for this - in
combination, they limit the drive voltage at the input to each triple to
about +/- 2.1 volts, relative to the output line.

MR106 affects the upper triple while MR 105 the lower triple.

The Vbes of TR103 and TR104 plus voltage drops across R120 and R121 &
R124 and R125 add to +/- 2.1 volts when the current flowing into a load is
+/- 4.5 amps, respectively. Current limiting is not sensitive to the phase
angle of the load impedance.

Under shorted or very low impedance load conditions, the power dissipation
in each output device limited to 70 watts, worst case.



........ Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Phil Allison
scribeth thus

"Phil Allison"

http://www.geocities.com/quad_esl63/...c/power303.jpg

** The output triples inherently limit at 4.5 amps.


** Silicon diodes MR105 & MR106 (along with TR7, the 1.4 volt Vbe
multiplier used for bias setting ) are responsible for this - in
combination, they limit the drive voltage at the input to each triple to
about +/- 2.1 volts, relative to the output line.

MR106 affects the upper triple while MR 105 the lower triple.

The Vbes of TR103 and TR104 plus voltage drops across R120 and R121 &
R124 and R125 add to +/- 2.1 volts when the current flowing into a load is
+/- 4.5 amps, respectively. Current limiting is not sensitive to the phase
angle of the load impedance.

Under shorted or very low impedance load conditions, the power dissipation
in each output device limited to 70 watts, worst case.



....... Phil



Correct me if I'm wrong, and I'm sure you will;!, but the voltage
regulator is involved in the protection?....
--
Tony Sayer

AudioMisc pages on early J. E. Sugden Class A amps
 

In article ,
Phil Allison wrote:
The interest in the Sugden amps mystifies me because they seem to be
so backward.


** A quirky, pommy amp only a quirky pommy could love.

I'd suggest you actually listen to one - especially into a pair of ELS 57s.
It sounds a deal cleaner than a 303 - although obviously slightly down on
power.

--
*Never put off until tomorrow what you can avoid altogether *

Dave Plowman London SW
To e-mail, change noise into sound.

AudioMisc pages on early J. E. Sugden Class A amps
 

"Dave Plowman (News)"


** A quirky, pommy amp only a quirky pommy could love.

I'd suggest you actually listen to one ....


** Yaaawnnnnnnn - more audiophool DRIVEL !!

I suggest you go drop dead.




........ Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

"tony sayer"


Correct me if I'm wrong, and I'm sure you will;!, but the voltage
regulator is involved in the protection?....



** See what I mean about " insufferable pommies " ??





....... Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Phil Allison
scribeth thus

"tony sayer"


Correct me if I'm wrong, and I'm sure you will;!, but the voltage
regulator is involved in the protection?....



** See what I mean about " insufferable pommies " ??




** No mate! I'm not quite as insufferable as some Aussie's !!!!


****** the old reg offers some current limiting dontcher tink ore
is that or **** ????? whoops ......................

thats the one;).......


...... Phil





--
Tony Sayer

AudioMisc pages on early J. E. Sugden Class A amps
 

In article ,
Phil Allison wrote:
** A quirky, pommy amp only a quirky pommy could love.

I'd suggest you actually listen to one ....


** Yaaawnnnnnnn - more audiophool DRIVEL !!

I suggest you go drop dead.

So that's your response to a reasonable point?

As it happens I've done just this test which is why I brought it up. And
thought it might be of interest even to you - thinking you may have
changed your attitude to attempts at sensible discussion. So back in the
killfile you go.

--
*Experience is something you don't get until just after you need it *

Dave Plowman London SW
To e-mail, change noise into sound.

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Dave Plowman (News)
wrote:
In article , Phil Allison
wrote:
** A quirky, pommy amp only a quirky pommy could love.

I'd suggest you actually listen to one ....


** Yaaawnnnnnnn - more audiophool DRIVEL !!

I suggest you go drop dead.

So that's your response to a reasonable point?

As it happens I've done just this test which is why I brought it up. And
thought it might be of interest even to you - thinking you may have
changed your attitude to attempts at sensible discussion. So back in the
killfile you go.

Which amp did you try?

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

AudioMisc pages on early J. E. Sugden Class A amps
 

"Dave Plowman (News)"

** A quirky, pommy amp only a quirky pommy could love.

I'd suggest you actually listen to one ....


** Yaaawnnnnnnn - more audiophool DRIVEL !!

I suggest you go drop dead.

So that's your response to a reasonable point?



** Audiophool drivel is inherently * ANTI * reason.

It is the exact, bloody OPPOSITE of reason .



I do most sincerely suggest YOU go and **** yourself.






........ Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

In article ,
Jim Lesurf wrote:
As it happens I've done just this test which is why I brought it up.
And thought it might be of interest even to you - thinking you may
have changed your attitude to attempts at sensible discussion. So back
in the killfile you go.

Which amp did you try?

All from a failing ;-) memory as it was a long time ago.

A pal was a great ELS fan - but wasn't happy with the 303 as a replacement
for his Quad II amps. And experimented with what I think was a borrowed
A21. And liked the sound. Actually bought the later 25 watt one (A42?)
which he stuck with for a long long time - despite trying the 405 etc.
And demonstrated the various combinations with which I agreed with on his
conclusions.

--
*Windows will never cease *

Dave Plowman London SW
To e-mail, change noise into sound.

AudioMisc pages on early J. E. Sugden Class A amps
 

"Dave Plowman (News)" wrote in message
...
In article ,
Phil Allison wrote:
The interest in the Sugden amps mystifies me because they seem to be
so backward.


** A quirky, pommy amp only a quirky pommy could love.

I'd suggest you actually listen to one - especially into a pair of ELS
57s.
It sounds a deal cleaner than a 303 - although obviously slightly down on
power.

Agreed. They are still highly sought after.

AudioMisc pages on early J. E. Sugden Class A amps
 

"Iain Cherchus Utter ****ing IDIOT "


Agreed.


** Kiss of death whenever this genetic retard agrees.






........ Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

"Dave Plowman (News)" wrote in message
...
In article ,
Jim Lesurf wrote:
As it happens I've done just this test which is why I brought it up.
And thought it might be of interest even to you - thinking you may
have changed your attitude to attempts at sensible discussion. So back
in the killfile you go.

Which amp did you try?

All from a failing ;-) memory as it was a long time ago.

A pal was a great ELS fan - but wasn't happy with the 303 as a replacement
for his Quad II amps. And experimented with what I think was a borrowed
A21. And liked the sound. Actually bought the later 25 watt one (A42?)
which he stuck with for a long long time - despite trying the 405 etc.
And demonstrated the various combinations with which I agreed with on his
conclusions.


Interesting observations. Thanks Dave. But how can that be reconciled with
the all amplifiers sound the same argument? :-)

Iain

LYING PITA SCUMBAG
 

"Iain Cherchus ****ing IDIOT "


Interesting observations. Thanks Dave. But how can that be reconciled with
the all amplifiers sound the same argument? :-)



** The Cherchus LYING PITA SCUMBAG

never gets sick of posting this ridiculous fabrication.

There are LIES, DAMN LIES and then there is the ****ING ****

that Iain Churches vomits out all over the place.


Killfile the vile cretin NOW !!!!!!!!!




....... Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Iain
Churches wrote:

"Dave Plowman (News)" wrote in message
...
In article , Jim Lesurf
wrote:
As it happens I've done just this test which is why I brought it
up. And thought it might be of interest even to you - thinking you
may have changed your attitude to attempts at sensible discussion.
So back in the killfile you go.

Which amp did you try?

All from a failing ;-) memory as it was a long time ago.

A pal was a great ELS fan - but wasn't happy with the 303 as a
replacement for his Quad II amps. And experimented with what I think
was a borrowed A21. And liked the sound. Actually bought the later 25
watt one (A42?) which he stuck with for a long long time - despite
trying the 405 etc. And demonstrated the various combinations with
which I agreed with on his conclusions.


Interesting observations. Thanks Dave. But how can that be reconciled
with the all amplifiers sound the same argument? :-)

I've not tried the A21 in any version, nor can I recall anyone claiming
that, "All amplifiers sound the same". Just that some/many may be
indistiguishable in appropriate use. :-) But in this case the differences
in the output impedances of the two amps might perhaps produce different
frequency responses with a load like the 57.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

AudioMisc pages on early J. E. Sugden Class A amps
 

"Jim Lesurf" wrote in message
...
In article , Iain
Churches wrote:


Interesting observations. Thanks Dave. But how can that be reconciled
with the all amplifiers sound the same argument? :-)

I've not tried the A21 in any version, nor can I recall anyone
claiming
that, "All amplifiers sound the same".


You either have a poor or a very selective memory, Jimbo - or you
perhaps were wise enough not to read all the posts from a former
subscriber here (the Roseate One) who frequently made the claim (as he
slid further into what appeared to be an AV/can't be arsed with 'audio'
vegetative state) that all amplifiers did more or less sound the same
with the preconditions that they were 'good', solid state and cost 300
UKP or more.


Just that some/many may be
indistiguishable in appropriate use. :-)


That's a different thing entirely - my view was always that the 'all
good amps sound the same' claim always depended on the other kit with
which they were/are being used. Interesting though, that the maggies
seem to lack no evidence to support their views that 'this amp' sounds
like this and 'that amp' sounds different on different material &c. ??


But in this case the differences
in the output impedances of the two amps might perhaps produce
different
frequency responses with a load like the 57.


There ya go for starters...

AudioMisc pages on early J. E. Sugden Class A amps
 

In article ,
Iain Churches wrote:
A pal was a great ELS fan - but wasn't happy with the 303 as a
replacement for his Quad II amps. And experimented with what I think
was a borrowed A21. And liked the sound. Actually bought the later 25
watt one (A42?) which he stuck with for a long long time - despite
trying the 405 etc. And demonstrated the various combinations with
which I agreed with on his conclusions.


Interesting observations. Thanks Dave. But how can that be reconciled
with the all amplifiers sound the same argument? :-)

No point in asking me that one, Iain. I can think of plenty amps that
don't sound 'the same'. Especially SET ones - hence their attraction to
those who aren't interested in an accurate sound but want something
'better'.

I also didn't agree with Allison's comment about the 303 never needing
adjustment.

--
*TEAMWORK...means never having to take all the blame yourself *

Dave Plowman London SW
To e-mail, change noise into sound.

AudioMisc pages on early J. E. Sugden Class A amps
 

"Dave Plowman (News)" wrote in message
...
In article ,
Iain Churches wrote:
A pal was a great ELS fan - but wasn't happy with the 303 as a
replacement for his Quad II amps. And experimented with what I
think
was a borrowed A21. And liked the sound. Actually bought the later
25
watt one (A42?) which he stuck with for a long long time - despite
trying the 405 etc. And demonstrated the various combinations with
which I agreed with on his conclusions.


Interesting observations. Thanks Dave. But how can that be reconciled
with the all amplifiers sound the same argument? :-)

No point in asking me that one, Iain. I can think of plenty amps that
don't sound 'the same'. Especially SET ones - hence their attraction
to
those who aren't interested in an accurate sound but want something
'better'.


Make that 'those who want greater *realism* and *listenability* over
accurate but blando-boring' and I'll sign that chitty...

(I listen to music to be *moved* - not just bloody *informed*....)

AudioMisc pages on early J. E. Sugden Class A amps
 

"Dave Plowman (News)"


I also didn't agree with Allison's comment about the 303 never needing
adjustment.


** You just make up any stupid, damn LIE you like and post it as fact.

What a VILE audiophool cretin you are.




........ Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

"Jim Lesurf"


I've not tried the A21 in any version, nor can I recall anyone claiming
that, "All amplifiers sound the same". Just that some/many may be
indistiguishable in appropriate use. :-) But in this case the differences
in the output impedances of the two amps might perhaps produce different
frequency responses with a load like the 57.


** The schem on your pages for the A21 shows the negative feedback being
taken from the speaker output - ie after the DC blocking cap.

However, the A21 " series 2" schem shows the take off point as being
shifted to the other side of that cap.

Makes a big difference, particularly if the load is the input tranny of an
ESL 57.

What not try modelling it ?




........ Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...
In article , Iain
Churches wrote:


Interesting observations. Thanks Dave. But how can that be reconciled
with the all amplifiers sound the same argument? :-)

I've not tried the A21 in any version, nor can I recall anyone
claiming that, "All amplifiers sound the same".


You either have a poor or a very selective memory, Jimbo - or you
perhaps were wise enough not to read all the posts from a former
subscriber here (the Roseate One) who frequently made the claim (as he
slid further into what appeared to be an AV/can't be arsed with 'audio'
vegetative state) that all amplifiers did more or less sound the same
with the preconditions that they were 'good', solid state and cost 300
UKP or more.

Well, perhaps it was sometimes claimed by one poster in a message that
*someone else* had said "All amplifiers sound the same".

But I can't recall anyone making such a statement with no qualifiers. If
you can, perhaps you can post the details of who, when, etc. - i.e. give
the date, time, title, etc, of the posting, and the full wording.

My recollection is that a more common claim was something like "all
qualifiers amplifiers sound the same (or indistinguishable) under
specified conditions of use.". Many people have said, this, from PJW
onwards. Alas, it then seems to be routinely changed to remove all
the specifics/qualifiers by someone else who dislikes what was said
and who wants to argue.

I think this is the a version of the 'Straw Man' debate technique. :-)


But in this case the differences
in the output impedances of the two amps might perhaps produce
different frequency responses with a load like the 57.


There ya go for starters...

Indeed. A point that has been made countless times in the past. And so far
as I recall, not contested by anyone who made the qualified claim I give
above. Since I can't recall anyone making the unqualified claim, I can't
say if they'd have objected to what I wrote. But if you can give specifics
I can check. :-)

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

AudioMisc pages on early J. E. Sugden Class A amps
 

"Jim Lesurf" wrote in message
...
In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...
In article ,
Iain
Churches wrote:


Interesting observations. Thanks Dave. But how can that be
reconciled
with the all amplifiers sound the same argument? :-)

I've not tried the A21 in any version, nor can I recall anyone
claiming that, "All amplifiers sound the same".


You either have a poor or a very selective memory, Jimbo - or you
perhaps were wise enough not to read all the posts from a former
subscriber here (the Roseate One) who frequently made the claim (as
he
slid further into what appeared to be an AV/can't be arsed with
'audio'
vegetative state) that all amplifiers did more or less sound the same
with the preconditions that they were 'good', solid state and cost
300
UKP or more.

Well, perhaps it was sometimes claimed by one poster in a message that
*someone else* had said "All amplifiers sound the same".


No, it was clearly stated on more than one occasion that 'all ss
amplifiers sound the same' by the poster (obliquely) referred to above.
When I queried this, I was told 'all *good* ss amplifiers sound the
same'. When I further queried what constituted a 'good' amplifier, I was
told 'anything 300 quid or over' - or words very much to that effect.

(Actually, FWIW, I have no problem with that argument - AFAIAC they do.
:-)



But I can't recall anyone making such a statement with no qualifiers.
If
you can, perhaps you can post the details of who, when, etc. - i.e.
give
the date, time, title, etc, of the posting, and the full wording.


Ain't gonna happen....



My recollection is that a more common claim was something like "all
qualifiers amplifiers sound the same (or indistinguishable) under
specified conditions of use.". Many people have said, this, from PJW
onwards. Alas, it then seems to be routinely changed to remove all
the specifics/qualifiers by someone else who dislikes what was said
and who wants to argue.

I think this is the a version of the 'Straw Man' debate technique. :-)


Possibly, but I have seen the phrase 'Straw Man' misapplied to so many
arguments that I no longer take any notice of it.

From the Whacky Wiki:

"A straw man argument is an informal fallacy based on misrepresentation
of an opponent's position. To "set up a straw man" or "set up a straw
man argument" is to create a position that is easy to refute , then
attribute that position to the opponent. A straw man argument can be a
successful rhetorical technique (that is, it may succeed in persuading
people) but it is in fact a misleading fallacy, because the opponent's
actual argument has not been refuted."

Does not apply here with the 'all ss amps sound the same' claim - that
was stated quite clearly by at least one poster who was very Rosy and
not at all Straw...





But in this case the differences
in the output impedances of the two amps might perhaps produce
different frequency responses with a load like the 57.


There ya go for starters...

Indeed. A point that has been made countless times in the past. And so
far
as I recall, not contested by anyone who made the qualified claim I
give
above. Since I can't recall anyone making the unqualified claim, I
can't
say if they'd have objected to what I wrote. But if you can give
specifics
I can check. :-)


Can't do it; wont do it - if nothing else, I'm busy 'grass-seeding' atm!

If it helps to quench this particular point of debate I'll happily
retract with a coppy 'OK, maybe I'm wrong then' as it isn't really worth
pursuing, in my book...

AudioMisc pages on early J. E. Sugden Class A amps
 

In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...



Can't do it; wont do it - if nothing else, I'm busy 'grass-seeding' atm!

I was grass cutting this morning. Finally got the right type of thread for
the strimmer.

Slainte,

Jim

--
Electronics http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc http://www.audiomisc.co.uk/index.html
Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html

AudioMisc pages on early J. E. Sugden Class A amps
 

"Keith G" wrote in message
...

"Jim Lesurf" wrote in message
...

Well, perhaps it was sometimes claimed by one poster in a message that
*someone else* had said "All amplifiers sound the same".

No, it was clearly stated on more than one occasion that 'all ss
amplifiers sound the same' by the poster (obliquely) referred to above.

If it happened so many times, then it should be easy to come up with a quote
from google.

I just did a search, and even after going back 10 years, I find no such
claims except as debating topics as opposed to actual claims.

When I queried this, I was told 'all *good* ss amplifiers sound the same'.
When I further queried what constituted a 'good' amplifier, I was told
'anything 300 quid or over' - or words very much to that effect.

Prove it.

But I can't recall anyone making such a statement with no qualifiers. If
you can, perhaps you can post the details of who, when, etc. - i.e. give
the date, time, title, etc, of the posting, and the full wording.


Ain't gonna happen....

Not unless someone gets careless.

AudioMisc pages on early J. E. Sugden Class A amps
 

"Arny Krueger" wrote in message
...

"Keith G" wrote in message
...

"Jim Lesurf" wrote in message
...

Well, perhaps it was sometimes claimed by one poster in a message
that
*someone else* had said "All amplifiers sound the same".

No, it was clearly stated on more than one occasion that 'all ss
amplifiers sound the same' by the poster (obliquely) referred to
above.

If it happened so many times, then it should be easy to come up with a
quote from google.

I just did a search, and even after going back 10 years, I find no
such claims except as debating topics as opposed to actual claims.

When I queried this, I was told 'all *good* ss amplifiers sound the
same'. When I further queried what constituted a 'good' amplifier, I
was told 'anything 300 quid or over' - or words very much to that
effect.

Prove it.


No, you prove it - start he

http://groups.google.co.uk/group/uk....10&sa=N&hl=en&


and work your way along...

AudioMisc pages on early J. E. Sugden Class A amps
 

"Keith G"


** YOU ARE A STINKING ****ING LIAR !!






....... Phil

AudioMisc pages on early J. E. Sugden Class A amps
 

"Keith G" wrote in message
...

"Arny Krueger" wrote in message
...

"Keith G" wrote in message
...

"Jim Lesurf" wrote in message
...

Well, perhaps it was sometimes claimed by one poster in a message that
*someone else* had said "All amplifiers sound the same".

No, it was clearly stated on more than one occasion that 'all ss
amplifiers sound the same' by the poster (obliquely) referred to above.

If it happened so many times, then it should be easy to come up with a
quote from google.

I just did a search, and even after going back 10 years, I find no such
claims except as debating topics as opposed to actual claims.

When I queried this, I was told 'all *good* ss amplifiers sound the
same'. When I further queried what constituted a 'good' amplifier, I was
told 'anything 300 quid or over' - or words very much to that effect.

Prove it.

No, you prove it - start he

http://groups.google.co.uk/group/uk....10&sa=N&hl=en&

Been there, done that. Things are as I said, above.

You know Keith, you're one arrogant POS if you think that you're the only
person around here who can come up with relevant retrievals from Google.

AudioMisc pages on early J. E. Sugden Class A amps
 

Jim Lesurf wrote:
In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...
In article , Iain
Churches wrote:


Interesting observations. Thanks Dave. But how can that be reconciled
with the all amplifiers sound the same argument? :-)
I've not tried the A21 in any version, nor can I recall anyone
claiming that, "All amplifiers sound the same".


You either have a poor or a very selective memory, Jimbo - or you
perhaps were wise enough not to read all the posts from a former
subscriber here (the Roseate One) who frequently made the claim (as he
slid further into what appeared to be an AV/can't be arsed with 'audio'
vegetative state) that all amplifiers did more or less sound the same
with the preconditions that they were 'good', solid state and cost 300
UKP or more.

Well, perhaps it was sometimes claimed by one poster in a message that
*someone else* had said "All amplifiers sound the same".

But I can't recall anyone making such a statement with no qualifiers. If
you can, perhaps you can post the details of who, when, etc. - i.e. give
the date, time, title, etc, of the posting, and the full wording.


I'm afraid I must shoulder some of the blame. It's my contention that
they don't sound the same - far from it.

A couple of people had the patience to explain that most SS amplifiers
built nowadays simply do sound the same to all intents and purposes given:

* a reasonable set of operating parameters, principally relating to
speakers;
* a certain specification, which most off the shelf integrated
amplifiers meet.

Serge (and you) guided me through the whole thing, but I became lost at
a crucial point of measurement (you measure the electrical
specification, I wanted to measure the sound; you said they were the
same thing; I said they might not), and left it at that. I can't get to
grips with google's newsgroup search, but here's a bit of the thread,
from Serge's contribution:

"Price of the amplifier isn't important. It is well recognised, at least
amongst audio professionals, that the ear's ability to hear differences has
a lower threshold. If an amplifier's performance is below that threshold,
then all differences between such amplifiers is not audible."

http://groups.google.co.uk/group/uk....99490883d4a4f8

AudioMisc pages on early J. E. Sugden Class A amps
 

"Arny Krueger" wrote in message
. ..

"Keith G" wrote in message
...

"Arny Krueger" wrote in message
...

"Keith G" wrote in message
...

"Jim Lesurf" wrote in message
...

Well, perhaps it was sometimes claimed by one poster in a message
that
*someone else* had said "All amplifiers sound the same".

No, it was clearly stated on more than one occasion that 'all ss
amplifiers sound the same' by the poster (obliquely) referred to
above.

If it happened so many times, then it should be easy to come up with
a quote from google.

I just did a search, and even after going back 10 years, I find no
such claims except as debating topics as opposed to actual claims.

When I queried this, I was told 'all *good* ss amplifiers sound the
same'. When I further queried what constituted a 'good' amplifier,
I was told 'anything 300 quid or over' - or words very much to that
effect.

Prove it.

No, you prove it - start he

http://groups.google.co.uk/group/uk....10&sa=N&hl=en&

Been there, done that. Things are as I said, above.

You know Keith, you're one arrogant POS if you think that you're the
only person around here who can come up with relevant retrievals from
Google.



Not half as arrogant as you, if you think that just because I lead you
to something by the nose that I consider *anybody* else here needs
leading similarly....

AudioMisc pages on early J. E. Sugden Class A amps
 

"Jim Lesurf" wrote in message
...
In article , Keith G
wrote:

"Jim Lesurf" wrote in message
...



Can't do it; wont do it - if nothing else, I'm busy 'grass-seeding'
atm!

I was grass cutting this morning. Finally got the right type of thread
for
the strimmer.


Won't use 'em - not since I strimmed a poor little frog by accident
(didn't see it). We've got too many frogs kicking about here to risk it
again!

Consequently, I have a petrol-driven Kawasaki strimmer here that I won't
ever again use myself or let anyone else have in case it happens again,
even elsewhere!

Hideous, destructive things...