"William Sommerwerck" wrote in message
. ..
"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.

Marketing people redefine the definitions all the time, and technology
marches on, and meanings change. There was a stupid argument in a NG
somewhere a while back over the "right" name for DB-9 connectors (they're
DE-9 evidently). But this person was haranguing people for being so dense
and uneducated for using the wrong term.

Since then, I have seen DB-9 used in manuals, articles and spec sheets. The
term, right or wrong, has come into common usage, and I'll bet even a NASA
purchasing agent knows what people are talking about, and the space shuttle
gets the right parts.

Peter Wieck in
rec.audio.tubes1193359133.733368.298360@o80g2000h se.googlegroups.com:

Denegrates those who actually know better.

Ah, Denegrates, me old profligate pomegranate ...

Denigrates

On Thu, 25 Oct 2007 20:32:51 -0300, robert casey wrote:

snip
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. But that'd be rather silly...

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...

snip


AFAIK classes AB and B are *always* PP, as they both depend on that mode
for cancellation of even harmonics. You just can't do that with SE output.

--
Mick (Working in a M$-free zone!)
Web: http://www.nascom.info http://mixpix.batcave.net

On Oct 25, 7:17 pm, "William Sommerwerck"
wrote:
"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.

Actually, William, what I was trying to explain to these clowns Graham
Stevenson, Arny Krueger and Don Pearce is that "under any signal
condition" totally negates the first part of the definition, that "the
output device(s)never cease conducting".

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.

It is worse than that with this bunch of self-styled "engineers": they
think that their personal animosities are a licence to redefine
definitions to embarrass their "enemies". In other words, they lie on
professional matters for personal reasons.

What sort of physics is that? It is past time for us to haul up
Stevenson, Krueger and Pearce, and to explain to them sternly that
personalities cannot ever substitute for the principles of physics.

Those three substandard jerks are an embarrassment to decent, honest
engineers everywhere.

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

Chel van Gennip wrote:

Andre Jute wrote [of Don Pearce]:
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.

There is a difference between an amplifier and a mode/class of
amplification.

I know, Chel. In fact I pointed out elsewhere that the class of
amplifier and the class of operation shouldn't be confused in casual
conversation because it leads to loose thinking. But I didn't think
that it was necessary to tell you guys that...

Some amplifiers, designed to operate in Class A, will
operate in Class C when input signals are exceeding specifications
(overdriven).

That is why we have this thread, to explain to the three self-styled
"engineers" Graham Stevenson, Arny Krueger and Don Pearce that a Class
A amplifier must have its signal limited or it is no longer a Class A
amplifier. How can any properly educated engineer not know that the
signal in an amplifier class is by necessity limited? Yet those three
signed their names repeatedly to a claim that Class A is
an amplification Class in which "the output device(s)never cease
conducting under any signal condition."

As you say, not when the signal is so large that the amp is driven
into Class C! What sort of low-fi would that be?

Here is the original post in full:

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

On Oct 26, 5:34 am, RdM wrote:
Peter Wieck in
rec.audio.tubes1193359133.733368.298...@o80g2000h se.googlegroups.com:

Denegrates those who actually know better.

Ah, Denegrates, me old profligate pomegranate ...

Denigrates

So who is the little illiterate Worthless Wiecky, pernicious
pornegranate, denigrating today?

Andre Jute
Pasticheur

In article ,
mick wrote:

On Thu, 25 Oct 2007 20:32:51 -0300, robert casey wrote:

snip
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. But that'd be rather silly...

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...

snip


AFAIK classes AB and B are *always* PP, as they both depend on that mode
for cancellation of even harmonics. You just can't do that with SE output.

That is presumably true in audio applications, but it isn't true in all
applications, for example single ended class AB and class B amplifiers
are often used in applications like Television broadcast transmitters.


Regards,

John Byrns

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

I gather that somehow this flame war has been going on for a while elsewhere
and someone recently added rec.audio.pro to the newsgroups line. I would
appreciate if people would remove it in the future because it does not belong
here. Thank you.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Andre Jute wrote:

What sort of physics is that? It is past time for us to haul up
Stevenson, Krueger and Pearce, and to explain to them sternly that
personalities cannot ever substitute for the principles of physics.

What it's time for is

A. for you to shut up.

B. for you to get an education in electronics.

Graham

In article .com,
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.

This raises the question of what is an engineer? The following are a
few of the many definitions I have heard.

1. The person responsible for the operation and maintenance of a
buildings infrastructure.

2. The person who drives a Train.

3. A person who has received an "engineering" degree from a University.

4. A person licensed to practice "engineering", similar to the way
Doctors and Lawyers are licensed.


Regards,

John Byrns

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