"Andre Jute" wrote in message
oups.com...
Trevor Wilson wrote:
Incorrect and innappropriate application
of NFB can damage an amplifier's performance.

Now you're getting it, sonny.

**Then say so. Stop telling half-truths. There is NOTHING wrong with NFB, as
long as it is appropriately applied.

Next, try not to describe as a liar
anyone who doesn't instantly subscribe to your fanatical faith in Blow
Jobs from Transvestites (BJTs) and soon the rest of us might take you
seriously.

**I only tell it like it is.

Here are a few of your lies (some of which you have backtracked on):

"Negative feedback, shorthanded as NFB, is the instant response of the audio
engineering fraternity to all ills, real, perceived, non-existent."

"How does negative feedback work?
Negative feedback is simply a negative voltage fed back from the output to
the input amplifying device to offset part of the harmonic distortion which
is present as a positive voltage. It costs nothing except a loss of gain and
a few side effects such as phase shift and possible instability which are
well known in the mathematical literature and more or less easily guarded
against depending on the level of NFB."

"Negative feedback is what gives all those 'blameless' transistor and big
PP tube amps their chillingly unnatural sound."

"(I know, because a sub-board I designed for a supplier to the trade turns
up in so many very expensive amps with so many different big names neatly
silkscreened on it..."

" Suppose, for the sake of simplicity, a superbly designed ultrafidelista
amp with some second harmonic and zero odd harmonics before NFB."

"Let me say that again: after NFB, third and higher harmonics will make up a
greater part of the distortion than before."

"Low volume levels perforce accounts for 99 per cent of audiophile listening
because we all have families or neighbours, and we would like to keep our
ears."

"And they still use Negative Feedback?"

"The case against NFB is that for 99 per cent of listening the NFB cure is
worse than the disease."

"It follows from the argument above that ultrafidelista should choose an
intrinsically linear topology and device which does not require added
negative feedback to 'linearize' the output."

"The intrinsically linear device is the thermionic tube in either its triode
form or as a pentode hogtied to work as a triode, which can be a most
pleasing alternative both economically and sonically."

"In comparative ABX tests conducted over a number of years, I found that
professional musicians, certified golden ears, choose the triode-linked
Class A1 PP ZNFB EL34 whenever it is present in the test over all other
contenders including SE 300B and 'blameless' high-NFB silicon."

"But transistor amps won't work at all without NFB!"

"Engineering hangers-on of transistor attempts at high fidelity, where the
measure of success is vanishing THD rather than sonic hedonism, pretend to
be enthusiasts for NFB."

"They sneer that low level listening, which 99 per cent of us prefer"

"According to them we should all be forced to listen at the high volume
level which suits NFB amps, which they call 'realistic'."

"This is a contemptible circular argument, only too characteristic of a
fascist mentality in a part of the audiophile spectrum which wants to
prescribe their arid vision without regard for our enjoyment."

"Almost everyone listens at low level most of the time."

"Negative feedback is a bodge."


Would you care to amend these lies and state PRECISELY what you mean?


--
Trevor Wilson
www.rageaudio.com.au

All I hear from Oinkerton is "Oink....oink oink oink......squeal, oink...."

I doubt he makes any thing.

Patrick Turner.







Stewart Pinkerton wrote:

On 24 Mar 2006 14:01:45 -0800, "Andre Jute" wrote:

Patrick Turner wrote:

I am now doing 845 amps, two per channel for 50 watts each.
I expect music to be real fine. Damping factor good, noise low,
bandwidth wide, distortions negligible and maybe I can add 6db of global NFB but
I doubt any difference due to some **added** NFB will be heard.

Depends on the speakers, the reduced output impedance may be useful.

You probably won't need the NFB. The biggest problem with 845 is not
deciding how much NFB to use but steeling yourself to let them out of
the door. 845 are God's own tube. I really hesitated when I needed the
space, wondering if I shouldn't keep the simple SET 845 rather than my
Millennium's End SV572-xx amps.

It's an excellent tube, as tubes go, but of course we've had seventy
years of progress since then.......

Trev has never done anything like this and simply doesn't understand.

It's not so difficult to open your mind to new experiences and new
ideas. But first one has to stop being a smartarse, and that I don't
think poor old Trevor can manage.

You of course would be the master of this art - except that your arse
is the smartest part of you.

With 845, just no need for the 106dB of added NFB used in SS amps.
I don't care a bit about what Trev says.

With SS, no need for the massive cost of the output transformer for 50
watts of single-ended tube amplification, plus of course you get much
better linearity than even the mighty 845 can manage. A really good
60-watt SS amp is very easy to implement these days - and you can buy
one for the cost of a pair of those OPTs...............

--

Stewart Pinkerton | Music is Art - Audio is Engineering

Posted Via Usenet.com Premium Usenet Newsgroup Services
----------------------------------------------------------
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On Sat, 25 Mar 2006 15:05:58 GMT, "Ian Iveson"
wrote:

Chris Hornbeck wrote


For example, the
gain of both tubes and transistors can be very sensitive to temperature.
With negative feedback, the important parameters of the amplifier are set
by a pair of resistors, whose properties can be made to be very stable and
independent of temperature.

Perhaps not the best example, because vacuum tubes operate
in their own very high temperature environment and were made
to tolerances impossible for semiconductors, buy yeah, a
feedback loop of a pair of resistors is a pretty durned
good reference.

Wot, no compensation? Is that possible?

More to the point, Chris's comment is bunk. Semiconductors are made to
tolerances of a couple of microns (less in the case of ICs), while
tubes are lucky if they're made to a tenth of a millimetre.
--

Stewart Pinkerton | Music is Art - Audio is Engineering

Posted Via Usenet.com Premium Usenet Newsgroup Services
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"Patrick Turner" wrote in message
...


Andre Jute wrote:

I must say, Wilson, I don't understand why you're getting your knickers
in a knot. You're like those bolshies I used to know who claimed that
anyone who wasn't willing to kill for "socialism" was only play-acting.
Are you really claiming that someone who merely uses the NFB he finds
lurking in DHTs can't belong to the club until he repents and uses
excessive amounts of loop NFB? Are you really claiming that the use of
lots and lots of NFB is a prerequisite for good audio design? Are you
really claiming that because a little NFB is a good thing, an unlimited
amount must therefore be better, and an infinite amount best of all?
Seems a bit immoderate to me, old chap.

You will find yourself arguing at a man who has a head full of solid
concrete.

**Really? Then, I take it, you approve of Jute's lies? That makes you an
idiot.

Trev will never see the whole picture, and has never designed or built any
amp in
the last 30 years.

**Wrong and irrelevant. I am discussing Jute's lies. That you approve of
Jute's lies says a great deal about you.

I try not to bother arguing the same old tired BS time after time.
He just likes hanging out in news groups and Bull****ting.
He has NEVER once contributed a single article of constructive advice on
tubecraft
at r.a.t.

**And why should I? Tube technology matured in 1966. There was nothing much
to be added beyond that time.




Your hysterical belief that I am "against" NFB is the product of your
unsophisticated literal-mindedness. There is no reason for NFB to be an
act of faith, like an on-off switch. For the record, quite contrary to
your silly claims about what I said, I believe the little NFB that
occurs naturally in triodes and in certain conservatively sanctioned
traditional topologies are A Good Thing. To avoid giving you another
apoplectic fit, I shan't repeat what I think of the excessive amounts
of NFB required to make transistors work at all.

If you think you can write a more compelling argument than I can about
the evils of excessive NFB, have at it. But every time I see you, like
the other techies you merely kibbitz what better men have written.

I am now doing 845 amps, two per channel for 50 watts each.
I expect music to be real fine. Damping factor good, noise low,
bandwidth wide, distortions negligible and maybe I can add 6db of global
NFB but
I doubt any difference due to some **added** NFB will be heard.

Trev has never done anything like this and simply doesn't understand.

**Anything like what? Be precise and relate it to my comments on Jute's
lies.


With 845, just no need for the 106dB of added NFB used in SS amps.
I don't care a bit about what Trev says.

**What do I say (WRT Jute's lies)? Be precise and relate his lies to your
own culpability in those lies.


--
Trevor Wilson
www.rageaudio.com.au

"Patrick Turner" wrote in message

All I hear from Oinkerton is "Oink....oink oink
oink......squeal, oink...."

I doubt he makes any thing.

Patrick Turner.


Yet another prerequisite subjectivist personal attack.

Patrick Turner wrote:



A colleague in Sydney is doing an SE amp with 6 x GM70 for 120 watts.
But it will be switchable to PP......its doable, 5 very good switches are needed, and I
did the OPT design.

Whether the GM70 is better than 845 is unknown.


IMHO, we found that the graphite GM70 is not as good as the copper GM70,
the copper GM70 was nicer than cheap Chinese 845's, but I don't know how
the newer metal plate 845 or NOS 845 would sit in that list.

Though, what do I know, I still prefer the 211 :-).

I would have thought that 4 graphite GM70's would be enough for 120w.

BTW, HF heating makes the GM70 a lot simpiler to use.

--
Nick

the copper GM70 was nicer than cheap Chinese 845's

Any experiences of how these work as low power PP amps, as 845 has done
for many users? I was thinking about 450v HT. Andy

Andy Evans wrote:
the copper GM70 was nicer than cheap Chinese 845's

Any experiences of how these work as low power PP amps, as 845 has done
for many users? I was thinking about 450v HT. Andy

At 450 V the 845 is a pretty crappy tube. At its rated B+ it's a
wonderful tube except it takes too much drive.

To get back to the subject of negative feedback, I firmly believe it's
very tough to make a worthwhile amp without modest amounts of NFB, but
that one should try to make the circuit as linear as possible before
applying NFB and use it in moderate amounts. Amplifiers with no NFB
(except for what is locally inherent in the devices, particularly
triode tubes) usually sound queefy and those with very high global NFB
usually sound hostile.

Trevor Wilson wrote:
Here are a few of your lies (some of which you have backtracked on):

And then this nutter Wilson lists:

-- a set of incontrovertible facts agreed by all parties, without
explaining how the facts straight out of the RDH can be a lie

-- a set of my opinions on matters of taste, without explaining how a
cultural taste can be a lie

-- and so on into astounding subdivisions of irrationality and
stupidity

Let's take just one example of what Wilson declares a lie. I wrote:

"Let me say that again: after NFB, third and higher harmonics will make up a
greater part of the distortion than before."

According to Wilson that is "a lie". Really? It is in fact a fact
(heh-heh) agreed between all informed parties that the NFB, while
reducing the *total* amount of distortion, by its very nature alters
the frequency distribution of the remaining distortion so that the odd
and higher harmonics make up a greater proportion of the recombinant
residual. That is several times spelt out in my original article which
causes Wilson to foam at the mouth. So tell us, Trevor-baby, how is my
statement lie?

I can't resist. Here's another statement (a rhetorical question,
actually) this blockhead Wilson singles out as "a lie":

"And they still use Negative Feedback?"

Uh, duh, Trevor-baby, are you now claiming that the entire audio world
has stopped using NFB? Amazing.

Below my signature I reprint Wilson's entire hysterical (and
hysterically funny) letter in full for connoisseurs of audio
fruitcakery.

What a blockhead.

Andre Jute

"Andre Jute" wrote in message
oups.com...
Trevor Wilson wrote:
Incorrect and innappropriate application
of NFB can damage an amplifier's performance.

Now you're getting it, sonny.

**Then say so. Stop telling half-truths. There is NOTHING wrong with NFB, as
long as it is appropriately applied.

Next, try not to describe as a liar
anyone who doesn't instantly subscribe to your fanatical faith in Blow
Jobs from Transvestites (BJTs) and soon the rest of us might take you
seriously.

**I only tell it like it is.

Here are a few of your lies (some of which you have backtracked on):

"Negative feedback, shorthanded as NFB, is the instant response of the audio
engineering fraternity to all ills, real, perceived, non-existent."

"How does negative feedback work?
Negative feedback is simply a negative voltage fed back from the output to
the input amplifying device to offset part of the harmonic distortion which
is present as a positive voltage. It costs nothing except a loss of gain and
a few side effects such as phase shift and possible instability which are
well known in the mathematical literature and more or less easily guarded
against depending on the level of NFB."

"Negative feedback is what gives all those 'blameless' transistor and big
PP tube amps their chillingly unnatural sound."

"(I know, because a sub-board I designed for a supplier to the trade turns
up in so many very expensive amps with so many different big names neatly
silkscreened on it..."

" Suppose, for the sake of simplicity, a superbly designed ultrafidelista
amp with some second harmonic and zero odd harmonics before NFB."

"Let me say that again: after NFB, third and higher harmonics will make up a
greater part of the distortion than before."

"Low volume levels perforce accounts for 99 per cent of audiophile listening
because we all have families or neighbours, and we would like to keep our
ears."

"And they still use Negative Feedback?"

"The case against NFB is that for 99 per cent of listening the NFB cure is
worse than the disease."

"It follows from the argument above that ultrafidelista should choose an
intrinsically linear topology and device which does not require added
negative feedback to 'linearize' the output."

"The intrinsically linear device is the thermionic tube in either its triode
form or as a pentode hogtied to work as a triode, which can be a most
pleasing alternative both economically and sonically."

"In comparative ABX tests conducted over a number of years, I found that
professional musicians, certified golden ears, choose the triode-linked
Class A1 PP ZNFB EL34 whenever it is present in the test over all other
contenders including SE 300B and 'blameless' high-NFB silicon."

"But transistor amps won't work at all without NFB!"

"Engineering hangers-on of transistor attempts at high fidelity, where the
measure of success is vanishing THD rather than sonic hedonism, pretend to
be enthusiasts for NFB."

"They sneer that low level listening, which 99 per cent of us prefer"

"According to them we should all be forced to listen at the high volume
level which suits NFB amps, which they call 'realistic'."

"This is a contemptible circular argument, only too characteristic of a
fascist mentality in a part of the audiophile spectrum which wants to
prescribe their arid vision without regard for our enjoyment."

"Almost everyone listens at low level most of the time."

"Negative feedback is a bodge."


Would you care to amend these lies and state PRECISELY what you mean?


--
Trevor Wilson
www.rageaudio.com.au

Trevor Wilson wrote:

"Patrick Turner" wrote in message
...


Andre Jute wrote:

I must say, Wilson, I don't understand why you're getting your knickers
in a knot. You're like those bolshies I used to know who claimed that
anyone who wasn't willing to kill for "socialism" was only play-acting.
Are you really claiming that someone who merely uses the NFB he finds
lurking in DHTs can't belong to the club until he repents and uses
excessive amounts of loop NFB? Are you really claiming that the use of
lots and lots of NFB is a prerequisite for good audio design? Are you
really claiming that because a little NFB is a good thing, an unlimited
amount must therefore be better, and an infinite amount best of all?
Seems a bit immoderate to me, old chap.

You will find yourself arguing at a man who has a head full of solid
concrete.

**Really? Then, I take it, you approve of Jute's lies? That makes you an
idiot.

First of all, Jute's Lies as you call them are merely his opinion.

Its a free world and I tolerate opinions; I do not necessarily agree with them,
and
it is my opinion that your head is so chock full of concrete that you draw the
absurd conconclusion
that I am a fool because you have erroneously assumed I agree with all of Jute's
ideas without question.

I have heard Jute on all this several times before, and would be wasting time to
flame him about his opinions.

Jute uses and tolerates quite a number of different amplifiers which include SET
without added loops of NFB.
Jute is pro tube craft.

Now Trev, do us all a favour and just **** off out of rec.audio.tubes because
you come here with a hammer.
On your way out, leave your tube breaking hammer in the re-cycle bin.

Come back when you have something constructive to say about tube craft,
and can share our craft in a practical way ( build a tube amp, ok ) and share
the experience in a tolerant spirit.

Patrick Turner.



Trev will never see the whole picture, and has never designed or built any
amp in
the last 30 years.

**Wrong and irrelevant. I am discussing Jute's lies. That you approve of
Jute's lies says a great deal about you.

I try not to bother arguing the same old tired BS time after time.
He just likes hanging out in news groups and Bull****ting.
He has NEVER once contributed a single article of constructive advice on
tubecraft
at r.a.t.

**And why should I? Tube technology matured in 1966. There was nothing much
to be added beyond that time.




Your hysterical belief that I am "against" NFB is the product of your
unsophisticated literal-mindedness. There is no reason for NFB to be an
act of faith, like an on-off switch. For the record, quite contrary to
your silly claims about what I said, I believe the little NFB that
occurs naturally in triodes and in certain conservatively sanctioned
traditional topologies are A Good Thing. To avoid giving you another
apoplectic fit, I shan't repeat what I think of the excessive amounts
of NFB required to make transistors work at all.

If you think you can write a more compelling argument than I can about
the evils of excessive NFB, have at it. But every time I see you, like
the other techies you merely kibbitz what better men have written.

I am now doing 845 amps, two per channel for 50 watts each.
I expect music to be real fine. Damping factor good, noise low,
bandwidth wide, distortions negligible and maybe I can add 6db of global
NFB but
I doubt any difference due to some **added** NFB will be heard.

Trev has never done anything like this and simply doesn't understand.

**Anything like what? Be precise and relate it to my comments on Jute's
lies.


With 845, just no need for the 106dB of added NFB used in SS amps.
I don't care a bit about what Trev says.

**What do I say (WRT Jute's lies)? Be precise and relate his lies to your
own culpability in those lies.

--
Trevor Wilson
www.rageaudio.com.au