On Oct 26, 2:27 am, "Phread" wrote:
"Multi-grid" wrote in oglegroups.com...
On Oct 26, 12:29 am, Andre Jute wrote:
IN RESPONSE TO THIS

You really have to wonder.

Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

The three "engineers" in question are Graham "Poopie" Stevenson, Don
"Bluster" Pearce and Arny "I spoke in error" Krueger. Apparently they
are perfectly unable to understand, after they have been told so a
handful of times already, that "any signal condition" includes
overdrive which turns even the correct part of the definition into
absurd nonsense.

Here's the sequence of their errors, with a small sample of their
abuse liberally spattered over the newsgroups:

First Andre Jute, he of the saintly patience, pointed out that Poopie
Stevenson made a silly error:

Poopie's absurd redefinition of Class A as
a Class in which "the output device(s)never cease conducting *under
any signal condition*," (emphasis added). It's ludicrous.

Then Poopie Stevenson confirmed:

It's actually the only accurate definition.

And Arny "I spoke in error" Krueger agreed without any qualification:

Agreed.

Then Andre Jute, he of the saintly patience even with fools, pointed
out that the two parts of redefinition are mutually exclusive:

Any amp can be driven out of class by excessive signal voltage.

Which Poopie tried to blow away with poor-quality smoke:

Overdriving to cut-off is merely gross abuse and a complete red herring /
irrelevance.

Fully supported of course by his yes-man, Arny "I spoke in error"
Krueger:

Agreed. Jute seems to be addicted to excluded-middle arguments. Kick out
those and the straw men, and he's hardly have anything to say. ;-)

Now Don Pearce tries to bluster the argument out with an obvious lie:

Can you overdrive a class A amp to cutoff? In my experience what
happens when you overdrive a class A amp is that one device saturates,
and the other sticks with its normal bias condition. There is no
circumstance in which I have ever managed to put a class A amplifier
output device into cutoff.

d

Of course, it is irrelevant (perhaps even commendable) that Don Pearce
lives such a dull and unadventurous life that he has never overdriven
a Class A amp; perhaps he doesn't own a Class A amp; on the evidence
in this thread he doesn't even know what a Class A amp is. What
matters is that Don Pearce, like Arny Krueger, supports Poopie
Stevenson's absurd definition of Class A operation as 360 degrees of
conduction "under any signal condition".

How can any properly educated engineer not know that the signal in an
amplifier class is by necessity limited?

It is difficult not to conclude that these three clowns, Stevenson,
Krueger and Pearce, are either not engineers, or were not properly
educated, or are too old and fat and slack to remember the basics they
were taught.

I have on previous occasions demonstrated what Poopie Stevenson's
claim of a University of London degree actually means: not very much,
as he got his degree from a jumped-up polytechnic (a British version
of the soldering schools Ludwig is addicted to) forced onto UL by a
socialist government trying to save a buck. Others have noted that
Krueger was "educated" at a community college I have never even heard
of. Who knows where Pearce was so misshapen as to believe that it
doesn't matter how much signal voltage you use in an amplifier?

Poopie Stevenson, Bluster Pearce and Erroneous Krueger are, in
engineering terms, ignorant and abusive clowns "under any signal
condition".

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain

IN RESPONSE TO THE ABOVE REASONE INDICTMENT, ERRONEOUS KRUEGER TELLS
US THIS:

On Oct 25, 10:31 am, "Arny Krueger" wrote:

"Andre Jute" wrote in message

roups.com...

Others have noted that
Krueger was "educated" at a community college I have never even heard of.

Just goes to show that Jute is so stupid and arrogant that he is willing to
go on record agreeing with the sockpuppet known as George Middius. AFAIK,
the lie that I ever attended a community college is a lie that was
originated on Usenet by the Middiot.

You're tight, Krueger, I merely reported what others said about you.

I graduated from Oakland University

Never heard of that one either. The rest of your post is poor-quality
smoke to avoid the main issue:

So, Arny "I spoke in error" Krueger, where is your excuse for claiming
that Class A must hold true "under any condition of signal"?

which has never been a community
college. It is the only degree-granting institution of higher education that
I've ever attended. True, there is an educational resource named Oakland
Community College, but it is a completely different institution.

The rest of Jute's post is about as truthful as this false claim.

Do you, Arny "I spoke in error" Krueger, deny that you agreed with
Poopie Stevenson that Class A must hold true "under any condition of
signal"?

Unsigned out of contempt for a liar and a fool

All hail the marketer cheap-Jute. When are you going to get back to
the definition of AB? back to claiming AB amps workin Class A for some
fraction of its rated power? good grief Chuck, go wait for the great
pumpkin.

So you run your amps with clipping inducing signal? Signal is only of
concern below the level required to deliver max power. What is the
value of discussing signal that overdrives the amp? Turn the volume
down fooool, or build a bigger amp.

Class A means the finals are at a minimum idling at half the current
they'll conduct at full power. It doesn't matter if the design can
deal with grid current or not. If it can, then of course power will be
higher than if it couldn't. Why would you worry about an AB amp's
behaviour under signal higher than required to deliver max
power( unless you're discussing the overload behaviour perhaps ). You
know what was meant, and at worst the idea was mis-spoken. Get a grip!
Cloud the issue, split

The part of the an AB amp's finals conducting together is not class A.
Your agreement isn't required, just like we don't need your approval
for the Sun to rise the next morning. It will rise regardless...
cheers,
Douglas

Doug, think for a minute about the description, "Class AB." What could
that possibly mean? That the amp operates part of the time in A and part
of the time in B? Why, Duh, that's exactly how a Class AB amp operates!
Must be why they call it Class AB!

There's a difference between a Class A amplifier and Class A operation.
A Class AB amplifier isn't a Class A amplifier but it is capable of Class A
Operation under certain conditions. That's *why* it's called Class AB.

Fred- Hide quoted text -

- Show quoted text -

Hey Fred,
An AB amp's behaviour is by definition AB. That it is like A and B
does not make it either. It is simply AB. Full 360 degree conduction
is A, and something around 180 is B. That AB has both an A and a B in
it does not mean it is a Class A part of the time and B for others.
Anything else is a marketing-induced misunderstanding.

But hey, I am not in charge here( thank God, not going to be held
responsible for the RAT mess! ), and you sure don't need my approval
to Believe, neh?
cheers,
Douglas

On Oct 25, 4:27 pm, "Phread" wrote:
"Multi-grid" wrote in oglegroups.com...
On Oct 26, 12:29 am, Andre Jute wrote:
You really have to wonder.

Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

The three "engineers" in question are Graham "Poopie" Stevenson, Don
"Bluster" Pearce and Arny "I spoke in error" Krueger. Apparently they
are perfectly unable to understand, after they have been told so a
handful of times already, that "any signal condition" includes
overdrive which turns even the correct part of the definition into
absurd nonsense.

Here's the sequence of their errors, with a small sample of their
abuse liberally spattered over the newsgroups:

First Andre Jute, he of the saintly patience, pointed out that Poopie
Stevenson made a silly error:

Poopie's absurd redefinition of Class A as
a Class in which "the output device(s)never cease conducting *under
any signal condition*," (emphasis added). It's ludicrous.

Then Poopie Stevenson confirmed:

It's actually the only accurate definition.

And Arny "I spoke in error" Krueger agreed without any qualification:

Agreed.

Then Andre Jute, he of the saintly patience even with fools, pointed
out that the two parts of redefinition are mutually exclusive:

Any amp can be driven out of class by excessive signal voltage.

Which Poopie tried to blow away with poor-quality smoke:

Overdriving to cut-off is merely gross abuse and a complete red herring /
irrelevance.

Fully supported of course by his yes-man, Arny "I spoke in error"
Krueger:

Agreed. Jute seems to be addicted to excluded-middle arguments. Kick out
those and the straw men, and he's hardly have anything to say. ;-)

Now Don Pearce tries to bluster the argument out with an obvious lie:

Can you overdrive a class A amp to cutoff? In my experience what
happens when you overdrive a class A amp is that one device saturates,
and the other sticks with its normal bias condition. There is no
circumstance in which I have ever managed to put a class A amplifier
output device into cutoff.

d

Of course, it is irrelevant (perhaps even commendable) that Don Pearce
lives such a dull and unadventurous life that he has never overdriven
a Class A amp; perhaps he doesn't own a Class A amp; on the evidence
in this thread he doesn't even know what a Class A amp is. What
matters is that Don Pearce, like Arny Krueger, supports Poopie
Stevenson's absurd definition of Class A operation as 360 degrees of
conduction "under any signal condition".

How can any properly educated engineer not know that the signal in an
amplifier class is by necessity limited?

It is difficult not to conclude that these three clowns, Stevenson,
Krueger and Pearce, are either not engineers, or were not properly
educated, or are too old and fat and slack to remember the basics they
were taught.

I have on previous occasions demonstrated what Poopie Stevenson's
claim of a University of London degree actually means: not very much,
as he got his degree from a jumped-up polytechnic (a British version
of the soldering schools Ludwig is addicted to) forced onto UL by a
socialist government trying to save a buck. Others have noted that
Krueger was "educated" at a community college I have never even heard
of. Who knows where Pearce was so misshapen as to believe that it
doesn't matter how much signal voltage you use in an amplifier?

Poopie Stevenson, Bluster Pearce and Erroneous Krueger are, in
engineering terms, ignorant and abusive clowns "under any signal
condition".

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain


The part of the an AB amp's finals conducting together is not class A.
Your agreement isn't required, just like we don't need your approval
for the Sun to rise the next morning. It will rise regardless...
cheers,
Douglas

Doug, think for a minute about the description, "Class AB." What could
that possibly mean? That the amp operates part of the time in A and part
of the time in B? Why, Duh, that's exactly how a Class AB amp operates!
Must be why they call it Class AB!

There's a difference between a Class A amplifier and Class A operation.
A Class AB amplifier isn't a Class A amplifier but it is capable of Class A
Operation under certain conditions. That's *why* it's called Class AB.

Fred

Precisely. "A Class AB amplifier ... is capable of Class A Operation
under certain conditions", one of those conditions being that the
signal should not be large enough to drive the amplifier beyond the
boundaries of Class A. That precludes "under any signal condition" as
Graham "Poopie" Stevenson has it, supported by Don "Bluster" Pearce
and Arny "I spoke in error" Krueger.

Thanks, Fred. I don't think you'll make a lot of impact on Multi-
grid's thick skull but you did your duty by trying.

Maybe you want next to try to educate the self-styled "engineers"
Graham "Poopie" Stevenson, Don "Bluster" Pearce and Arny "I spoke in
error" Krueger.

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain

Poopie Stevenson, aka Eeyore
wrote:
Andre Jute wrote:
Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

And of course they are correct. It is the very textbook DEFINITION of Class A.

Graham

Name one textbook that includes the words "under any signal condition"
in the definition of Class A.

You can't because the qualification entirely negates the definition of
Class A.

No real engineer would put such a travesty into a textbook. Graham
"Poopie" Stevenson, Don "Bluster" Pearce and Arny "I spoke in error"
Krueger are wrong.

If you don't know it, you don't belong here.

After this display of gross ignorance, Graham "Poopie" Stevenson, Don
"Bluster" Pearce and Arny "I spoke in error" Krueger shouldn't call
themselves "engineers".

Andre Jute
Visit Jute on Amps at http://members.lycos.co.uk/fiultra/
"wonderfully well written and reasoned information
for the tube audio constructor"
John Broskie TubeCAD & GlassWare
"an unbelievably comprehensive web site
containing vital gems of wisdom"
Stuart Perry Hi-Fi News & Record Review

HERE IS THE ORIGINAL POST IN THIS THREAD FOR THOSE WHO MISSED IT:

You really have to wonder.

Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

The three "engineers" in question are Graham "Poopie" Stevenson, Don
"Bluster" Pearce and Arny "I spoke in error" Krueger. Apparently they
are perfectly unable to understand, after they have been told so a
handful of times already, that "any signal condition" includes
overdrive which turns even the correct part of the definition into
absurd nonsense.

Here's the sequence of their errors, with a small sample of their
abuse liberally spattered over the newsgroups:

First Andre Jute, he of the saintly patience, pointed out that Poopie
Stevenson made a silly error:

Poopie's absurd redefinition of Class A as
a Class in which "the output device(s)never cease conducting *under
any signal condition*," (emphasis added). It's ludicrous.

Then Poopie Stevenson confirmed:
It's actually the only accurate definition.

And Arny "I spoke in error" Krueger agreed without any qualification:
Agreed.

Then Andre Jute, he of the saintly patience even with fools, pointed
out that the two parts of redefinition are mutually exclusive:
Any amp can be driven out of class by excessive signal voltage.

Which Poopie tried to blow away with poor-quality smoke:
Overdriving to cut-off is merely gross abuse and a complete red herring /
irrelevance.

Fully supported of course by his yes-man, Arny "I spoke in error"
Krueger:
Agreed. Jute seems to be addicted to excluded-middle arguments. Kick out
those and the straw men, and he's hardly have anything to say. ;-)

Now Don Pearce tries to bluster the argument out with an obvious lie:
Can you overdrive a class A amp to cutoff? In my experience what
happens when you overdrive a class A amp is that one device saturates,
and the other sticks with its normal bias condition. There is no
circumstance in which I have ever managed to put a class A amplifier
output device into cutoff.
d


Of course, it is irrelevant (perhaps even commendable) that Don
Pearce
lives such a dull and unadventurous life that he has never overdriven
a Class A amp; perhaps he doesn't own a Class A amp; on the evidence
in this thread he doesn't even know what a Class A amp is. What
matters is that Don Pearce, like Arny Krueger, supports Poopie
Stevenson's absurd definition of Class A operation as 360 degrees of
conduction "under any signal condition".
How can any properly educated engineer not know that the signal in an
amplifier class is by necessity limited?

It is difficult not to conclude that these three clowns, Stevenson,
Krueger and Pearce, are either not engineers, or were not properly
educated, or are too old and fat and slack to remember the basics
they
were taught.

I have on previous occasions demonstrated what Poopie Stevenson's
claim of a University of London degree actually means: not very much,
as he got his degree from a jumped-up polytechnic (a British version
of the soldering schools Ludwig is addicted to) forced onto UL by a
socialist government trying to save a buck. Others have noted that
Krueger was "educated" at a community college I have never even heard
of. Who knows where Pearce was so misshapen as to believe that it
doesn't matter how much signal voltage you use in an amplifier?

Poopie Stevenson, Bluster Pearce and Erroneous Krueger are, in
engineering terms, ignorant and abusive clowns "under any signal
condition".

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain

If anyone wishes to see inside what passes for Andre's head, I suggest
that they read:

http://etext.lib.virginia.edu/toc/mo...c/CarSnar.html

Read it through. The Bellman is a gentle version of Andre, vapid and
not of this world, and with about as similar a perception of reality.
Add some pretense, add some Munchausen, more than a bit of ego, remove
any slight amount of good intent, and you would be left with Andre.

Proof by repetition.
Blank maps needing no explanation.
Denegrates those who actually know better.
Manages expeditions that result in no good ends.
Uses surrogates when challenged.

Peter Wieck
Wyncote, PA

Andre Jute wrote:

You really have to wonder.

Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

The three "engineers" in question are Graham "Poopie" Stevenson, Don
"Bluster" Pearce and Arny "I spoke in error" Krueger. Apparently they
are perfectly unable to understand, after they have been told so a
handful of times already, that "any signal condition" includes
overdrive which turns even the correct part of the definition into
absurd nonsense.

Here's the sequence of their errors, with a small sample of their
abuse liberally spattered over the newsgroups:

First Andre Jute, he of the saintly patience, pointed out that Poopie
Stevenson made a silly error:

Poopie's absurd redefinition of Class A as
a Class in which "the output device(s)never cease conducting *under
any signal condition*," (emphasis added). It's ludicrous.

Then Poopie Stevenson confirmed:
It's actually the only accurate definition.

And Arny "I spoke in error" Krueger agreed without any qualification:
Agreed.

Then Andre Jute, he of the saintly patience even with fools, pointed
out that the two parts of redefinition are mutually exclusive:
Any amp can be driven out of class by excessive signal voltage.

Which Poopie tried to blow away with poor-quality smoke:
Overdriving to cut-off is merely gross abuse and a complete red herring /
irrelevance.

Fully supported of course by his yes-man, Arny "I spoke in error"
Krueger:
Agreed. Jute seems to be addicted to excluded-middle arguments. Kick out
those and the straw men, and he's hardly have anything to say. ;-)

Now Don Pearce tries to bluster the argument out with an obvious lie:
Can you overdrive a class A amp to cutoff? In my experience what
happens when you overdrive a class A amp is that one device saturates,
and the other sticks with its normal bias condition. There is no
circumstance in which I have ever managed to put a class A amplifier
output device into cutoff.

d

Of course, it is irrelevant (perhaps even commendable) that Don Pearce
lives such a dull and unadventurous life that he has never overdriven
a Class A amp; perhaps he doesn't own a Class A amp; on the evidence
in this thread he doesn't even know what a Class A amp is. What
matters is that Don Pearce, like Arny Krueger, supports Poopie
Stevenson's absurd definition of Class A operation as 360 degrees of
conduction "under any signal condition".

How can any properly educated engineer not know that the signal in an
amplifier class is by necessity limited?

It is difficult not to conclude that these three clowns, Stevenson,
Krueger and Pearce, are either not engineers, or were not properly
educated, or are too old and fat and slack to remember the basics they
were taught.

I have on previous occasions demonstrated what Poopie Stevenson's
claim of a University of London degree actually means: not very much,
as he got his degree from a jumped-up polytechnic (a British version
of the soldering schools Ludwig is addicted to) forced onto UL by a
socialist government trying to save a buck. Others have noted that
Krueger was "educated" at a community college I have never even heard
of. Who knows where Pearce was so misshapen as to believe that it
doesn't matter how much signal voltage you use in an amplifier?

Poopie Stevenson, Bluster Pearce and Erroneous Krueger are, in
engineering terms, ignorant and abusive clowns "under any signal
condition".

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain

About 25 years ago a guy figured out how to drive a complementary pair
of BJTs or mosfets in a follower config
so that neither devices ever actually cut right off, and he did it using
opamps with a
non linear loop of NFB which gave the driver pure square law character,
so sharp switch off simply never ever occurred.
Bias was higher than usual though, to allow the gradual reduction of
idle current.
I recall his name was a Mr Sandman, from an Electronics World article.

He called his amplifier a class S type, a version of class A.

I cannot think of any brandname amp with the technique.

Virtually class A. It gave astonishingly low high order distortions
compared to all those gizmos which switched off and on again
during each 1/2 wave cycle.
So the usual heavy loop of global NFB had a much simpler easier task of
cleaning up the signal.

People had been doing it for 50 years with triodes, but anyway,
wonders will never cease.

Patrick Turner.

On Oct 25, 8:07 pm, Andre Jute wrote:
You really have to wonder.

Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

The three "engineers" in question are Graham "Poopie" Stevenson, Don
"Bluster" Pearce and Arny "I spoke in error" Krueger. Apparently they
are perfectly unable to understand, after they have been told so a
handful of times already, that "any signal condition" includes
overdrive which turns even the correct part of the definition into
absurd nonsense.

Here's the sequence of their errors, with a small sample of their
abuse liberally spattered over the newsgroups:

First Andre Jute, he of the saintly patience, pointed out that Poopie
Stevenson made a silly error:

Poopie's absurd redefinition of Class A as
a Class in which "the output device(s)never cease conducting *under
any signal condition*," (emphasis added). It's ludicrous.

Then Poopie Stevenson confirmed:

It's actually the only accurate definition.

And Arny "I spoke in error" Krueger agreed without any qualification:

Agreed.

Then Andre Jute, he of the saintly patience even with fools, pointed
out that the two parts of redefinition are mutually exclusive:

Any amp can be driven out of class by excessive signal voltage.

Which Poopie tried to blow away with poor-quality smoke:

Overdriving to cut-off is merely gross abuse and a complete red herring /
irrelevance.

Fully supported of course by his yes-man, Arny "I spoke in error"
Krueger:

Agreed. Jute seems to be addicted to excluded-middle arguments. Kick out
those and the straw men, and he's hardly have anything to say. ;-)

Now Don Pearce tries to bluster the argument out with an obvious lie:

Can you overdrive a class A amp to cutoff? In my experience what
happens when you overdrive a class A amp is that one device saturates,
and the other sticks with its normal bias condition. There is no
circumstance in which I have ever managed to put a class A amplifier
output device into cutoff.

d

Of course, it is irrelevant (perhaps even commendable) that Don Pearce
lives such a dull and unadventurous life that he has never overdriven
a Class A amp; perhaps he doesn't own a Class A amp; on the evidence
in this thread he doesn't even know what a Class A amp is. What
matters is that Don Pearce, like Arny Krueger, supports Poopie
Stevenson's absurd definition of Class A operation as 360 degrees of
conduction "under any signal condition".

How can any properly educated engineer not know that the signal in an
amplifier class is by necessity limited?

It is difficult not to conclude that these three clowns, Stevenson,
Krueger and Pearce, are either not engineers, or were not properly
educated, or are too old and fat and slack to remember the basics they
were taught.

I have on previous occasions demonstrated what Poopie Stevenson's
claim of a University of London degree actually means: not very much,
as he got his degree from a jumped-up polytechnic (a British version
of the soldering schools Ludwig is addicted to) forced onto UL by a
socialist government trying to save a buck. Others have noted that
Krueger was "educated" at a community college I have never even heard
of. Who knows where Pearce was so misshapen as to believe that it
doesn't matter how much signal voltage you use in an amplifier?

Poopie Stevenson, Bluster Pearce and Erroneous Krueger are, in
engineering terms, ignorant and abusive clowns "under any signal
condition".

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain

Andre,
Please list one instance where your personal attacks and general
nastiness has helped forward your goal.
cheers,
Douglas

On Oct 25, 4:32 pm, robert casey wrote:
Andre Jute wrote:
You really have to wonder.

Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

Let's see, I graduated Syracuse University in 1978 with a BSEE, so I'd
be an engineer.

You're observably an engineer, Robert, I'm writing about "engineers",
who are observably something else, most easily spotted by their
symptomatic tailoring of electronic truths to their personal
animosities.

For class A, I'd add the condition "if the input signal
level doesn't drive the amp into distortion or clipping" to "_all_ the
output device(s)never cease conducting under any signal condition.".

It is such an obvious condition that most texts leave it to the
reader's good sense to add to the definition. This thread is
particularly about Graham Stevenson, Don Pearce and Arny Krueger
explicitly claiming the opposite is true, trying for malicious
personal reasons to redefine Class A operation as one in which "the
output device(s) never cease conducting under any signal condition."

I
also added "all" to make it clear that each and every output device
never turns off. I've seen class A amps that had push-pull tubes, each
tube configured to never shut off, thru out the entire waveform cycle.
This would help reduce 2nd harmonic distortions (or have perfect
cancellation IF both tubes have identical characteristics and fed
identical except inverted signals).

Dream on. I've seen KT66 that after fifty years of use were more
closely matched than new-production EL34.

Okay, how about class AB? That's usually a push pull configuration
where, at or near zero crossing, both devices are conducting. But get
above, say 10% of maximum input signal level, one of the devices stops
conducting, and the other device is doing the work. Lets also say that
this is a 100W amplifier, if you run it with an input signal that makes
only 1 watt (the volume control is set low), then, sure you could call
it a 1 watt class A amp.

I wouldn't call it a Class A amp. I would say "it has 1W in Class A
and xWatts in Class B". It seems to me worth keeping the distinction
between an amplifier class and an operatiing class; it pleases me as a
wordsmith that the verbal distinction makes Class AB possible; if we
could not express it, we might not think of it. A Class A amplifier is
one in which up to the maximum specified signal no device ever ceases
conducting.

(Had to get down a new keyboard. Sputtered my wine across the previous
one. First time in years I had poor Australian wine. Some ponce at the
studio recommended it as "earthy". In raal life it tastes like the
peapod peepee made by some vegetarian ladies I dined with once and
never again -- nut cutlets, yech! --, and then only because I owed the
brother of one, who I knew at HP, a favour -- he was one of the
designers of my 400W party amps for entertaining only 800 of my
closest friends. Back to the good stuff!)

Class B is where there is no class A overlap. Sure, you could have low
quiescent current, but you could easily have crossover distortion. And
it'd sound like a cheap op-amp...

And there's class C, but that's not usable in audio work. It's used in
FM RF transmitters, where the distortions are filtered out.

And there's class D, which IIRC is a pulse width modulation scheme with
a clock running at about 10X the highest audio frequency. And heavy low
pass filtering to remove the clock and its harmonics. Mainly used in
solid state amps, and even there it's not real common.

Thanks for the straighforward analysis. You realize of course that you
and Phil Allison by demystifying the facts so bluntly are spoling my
fun kicking the enemies of fidelity around.

Andre Jute
Impedance is futile, you will be simulated into the triode of the
Borg. -- Robert Casey

"Andre Jute" wrote in message
oups.com...
Poopie Stevenson, aka Eeyore
wrote:
Andre Jute wrote:
Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

And of course they are correct. It is the very textbook DEFINITION
of Class A.

No it's noy. In class A, the devices amplify the entire waveform, all the
positive parts and all the negative parts. The device never cuts off, but
that's not the definition.

Many years back, Pioneer came up with a class AB transistor amp in which the
bias was clamped in such a way that the devices never cut off. But that
didn't make the amp class A.

This is a classic example -- common among engineers, and very common in this
group -- of thinking you understand things you have no comprehension of.

"Andre Jute" wrote in message oups.com...
On Oct 25, 4:27 pm, "Phread" wrote:
"Multi-grid" wrote in oglegroups.com...
On Oct 26, 12:29 am, Andre Jute wrote:
You really have to wonder.

Here we have three self-proclaimed engineers claiming that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

The three "engineers" in question are Graham "Poopie" Stevenson, Don
"Bluster" Pearce and Arny "I spoke in error" Krueger. Apparently they
are perfectly unable to understand, after they have been told so a
handful of times already, that "any signal condition" includes
overdrive which turns even the correct part of the definition into
absurd nonsense.

Here's the sequence of their errors, with a small sample of their
abuse liberally spattered over the newsgroups:

First Andre Jute, he of the saintly patience, pointed out that Poopie
Stevenson made a silly error:

Poopie's absurd redefinition of Class A as
a Class in which "the output device(s)never cease conducting *under
any signal condition*," (emphasis added). It's ludicrous.

Then Poopie Stevenson confirmed:

It's actually the only accurate definition.

And Arny "I spoke in error" Krueger agreed without any qualification:

Agreed.

Then Andre Jute, he of the saintly patience even with fools, pointed
out that the two parts of redefinition are mutually exclusive:

Any amp can be driven out of class by excessive signal voltage.

Which Poopie tried to blow away with poor-quality smoke:

Overdriving to cut-off is merely gross abuse and a complete red herring /
irrelevance.

Fully supported of course by his yes-man, Arny "I spoke in error"
Krueger:

Agreed. Jute seems to be addicted to excluded-middle arguments. Kick out
those and the straw men, and he's hardly have anything to say. ;-)

Now Don Pearce tries to bluster the argument out with an obvious lie:

Can you overdrive a class A amp to cutoff? In my experience what
happens when you overdrive a class A amp is that one device saturates,
and the other sticks with its normal bias condition. There is no
circumstance in which I have ever managed to put a class A amplifier
output device into cutoff.

d

Of course, it is irrelevant (perhaps even commendable) that Don Pearce
lives such a dull and unadventurous life that he has never overdriven
a Class A amp; perhaps he doesn't own a Class A amp; on the evidence
in this thread he doesn't even know what a Class A amp is. What
matters is that Don Pearce, like Arny Krueger, supports Poopie
Stevenson's absurd definition of Class A operation as 360 degrees of
conduction "under any signal condition".

How can any properly educated engineer not know that the signal in an
amplifier class is by necessity limited?

It is difficult not to conclude that these three clowns, Stevenson,
Krueger and Pearce, are either not engineers, or were not properly
educated, or are too old and fat and slack to remember the basics they
were taught.

I have on previous occasions demonstrated what Poopie Stevenson's
claim of a University of London degree actually means: not very much,
as he got his degree from a jumped-up polytechnic (a British version
of the soldering schools Ludwig is addicted to) forced onto UL by a
socialist government trying to save a buck. Others have noted that
Krueger was "educated" at a community college I have never even heard
of. Who knows where Pearce was so misshapen as to believe that it
doesn't matter how much signal voltage you use in an amplifier?

Poopie Stevenson, Bluster Pearce and Erroneous Krueger are, in
engineering terms, ignorant and abusive clowns "under any signal
condition".

Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain


The part of the an AB amp's finals conducting together is not class A.
Your agreement isn't required, just like we don't need your approval
for the Sun to rise the next morning. It will rise regardless...
cheers,
Douglas

Doug, think for a minute about the description, "Class AB." What could
that possibly mean? That the amp operates part of the time in A and part
of the time in B? Why, Duh, that's exactly how a Class AB amp operates!
Must be why they call it Class AB!

There's a difference between a Class A amplifier and Class A operation.
A Class AB amplifier isn't a Class A amplifier but it is capable of Class A
Operation under certain conditions. That's *why* it's called Class AB.

Fred

Precisely. "A Class AB amplifier ... is capable of Class A Operation
under certain conditions", one of those conditions being that the
signal should not be large enough to drive the amplifier beyond the
boundaries of Class A. That precludes "under any signal condition" as
Graham "Poopie" Stevenson has it, supported by Don "Bluster" Pearce
and Arny "I spoke in error" Krueger.

Thanks, Fred. I don't think you'll make a lot of impact on Multi-
grid's thick skull but you did your duty by trying.

Maybe you want next to try to educate the self-styled "engineers"
Graham "Poopie" Stevenson, Don "Bluster" Pearce and Arny "I spoke in
error" Krueger.

I find Don Pearce's posts on RAT and RAP to be informative. Arny and
Graham are beyond education because they already know it all. Just ask
one of them; they'll be happy to tell you.

Fred
Andre Jute
The trouble with most people is not what they don't know, but what
they know for certain that isn't true. ---Mark Twain

In article ,
robert casey wrote:

And there's class C, but that's not usable in audio work. It's used in
FM RF transmitters, where the distortions are filtered out.

Class C amps are not just used in "FM RF transmitters", but also in AM
RF transmitters, and other applications too.


Regards,

John Byrns

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