Output classes A and AB
 

Andre Jute wrote:

Eeyore wrote:

Andre Jute wrote:

In the halflight dreamworld inhabited by Dougles Zero-sound, Poopie
Stevenson and Worthless Wiecky, SE amps would be impossible, Class A1
amps would be impossible, and all other classes would produce zero
music -- in fact all other classes would produce 100 per cent pure
noise by being operated at all sonic peaks at either max current and
zero voltage or zero current and voltage plate overvoltage. All of
that follows logically from 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.

It's actually the only accurate definition.

I've already demonstrated several times that your words "under
any signal condition" make your definition grossly inaccurate.

But you're an ignorant **** and what you say is a load of ********.

"In a Class A circuit, the amplifying element is biased so the device is always
conducting to some extent"
http://en.wikipedia.org/wiki/Electro...lifier#Class_A

You're confusing cause and effect but your brain is too addled to understand the
difference.

Graham

Output classes A and AB
 

Andre Jute wrote:

Eeyore wrote:

You really should constrain yourself to talkind about stuff you understand.
Which would seem not to be very much going by your posting history.

Me? Come on, Poopie, I'm not the one who claimed for several days that
a Class A stage is one in which "the output device(s)never cease
conducting *under any signal condition*." You're the one who committed
that stupidity, and so many others.

And * so many others* too eh ? Ever consided we might actually be right ?

You're a ****ING CRETIN Joot. Go back to the miserable hole you crawled out of.

Graham

Output classes A and AB
 

Andre Jute wrote:

Poopie Stevenson aka Eeyore
wrote:
John Byrns wrote:
Andre Jute wrote:

Historically, the original purpose of Class AB was to annihilate the
second harmonic which before made up such a very large part of the
THD, while still allowing beam tubes and pentodes to give much larger
power than available before.

Andre, why was Class AB necessary to annihilate the second harmonic,
didn't Push Pull operation already annihilate the second harmonic
irrespective of the class of operation?

Yes, you are right. It does.

The SOLE purpose of AB is to produce larger power outputs using the same tubes.

Now this poor dumb slow learner Poopie Stevenson, an embarrassment to
everyone who comes into contact with him, claims to know more than the
RDH4! Yo, Poopie, in the RDH4 (Newnes 1997) on p 545 we find this
nugget of authoritative information by F. Langford-Smith B.Sc. B.E.
himself:

"Class AB operation indicates overbiased conditions, and is used only
in push-pull to balance out the even harmonics."

It's the push-pull that cancels those harmonics YOU UTTER CRETIN ! A Class **A**
push-pull output stage will do that too.

AB operation has NOTHING to do with distortion cancellation.

Your problem is that you don't understand what you'r reading so you quote out of
context as a result of your utter IGNORANCE.

Graham

Output classes A and AB
 

On Thu, 25 Oct 2007 10:26:32 +0100, Eeyore
wrote:



Andre Jute wrote:

Poopie Stevenson aka Eeyore
wrote:
John Byrns wrote:
Andre Jute wrote:

Historically, the original purpose of Class AB was to annihilate the
second harmonic which before made up such a very large part of the
THD, while still allowing beam tubes and pentodes to give much larger
power than available before.

Andre, why was Class AB necessary to annihilate the second harmonic,
didn't Push Pull operation already annihilate the second harmonic
irrespective of the class of operation?

Yes, you are right. It does.

The SOLE purpose of AB is to produce larger power outputs using the same tubes.

Now this poor dumb slow learner Poopie Stevenson, an embarrassment to
everyone who comes into contact with him, claims to know more than the
RDH4! Yo, Poopie, in the RDH4 (Newnes 1997) on p 545 we find this
nugget of authoritative information by F. Langford-Smith B.Sc. B.E.
himself:

"Class AB operation indicates overbiased conditions, and is used only
in push-pull to balance out the even harmonics."

It's the push-pull that cancels those harmonics YOU UTTER CRETIN ! A Class **A**
push-pull output stage will do that too.

AB operation has NOTHING to do with distortion cancellation.

Your problem is that you don't understand what you'r reading so you quote out of
context as a result of your utter IGNORANCE.

Graham

Graham, please just killfile the idiot like most of us have. His
dribbling meanderings are just as irritating at second hand as they
are when they have dropped fresh from his rear end.

d

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

GM V8-6-4 (was Output classes A and AB)
 

"John Byrns" wrote in message
...
In article .com,
Peter Wieck wrote:

Which, of course, would be a 100% marketing ploy, wouldn't it? To call
it a 4 or a 6 by virtue of the modifications?

If not a rhetorical question, then this is a straw man argument, as the
relevant products are still called V-8s by the marketing people.

I'm not sure it was a pure marketing ploy, especially given that I have
seen ads for a current model car that uses this same idea today,
unfortunately I forget what car it is, it might even be a Cadillac,
although I would think they would be too gun shy to try it again.

AFAIK, the technology is being used in current production GM and Chrysler
cars. I have friends who drive them.

At
any rate the reason I started this sub thread was to ask if anyone more
knowledgeable about engines than you or I knows the theory of the 8-6-4
engine and how it was supposed to improve gasoline mileage, which as I
remember it was what the hype said it was supposed to do?

A cylinder in a gas engine uses more energy if it is only partially in use
than if it is turned off. Some losses stay about the same, but other losses
are vastly reduced if you partially turn the cylinder off by means of
significantly altering the valve timing. AFAIK, the spark plug still fires
but no fuel is injected, and the amount of air that the cylinder pumps is
vastly reduced.

As a purpose-built 4 or 6 would be a much better solution, wouldn't
it?

Better solution for what problem?

Better than operating with a very tightly closed throttle. The engines that
receive this treatment are relatively large and powerful. They are
agressively throttled back most of the time.

And that same purpose-built 4 or 6 could be made with the same
displacement, potential output HP and torque as a V8, couldn't it?

Approximately yes. Engines are built with as many cylinders as possible to
smooth the noise and vibration. They are built with as few cylinders as
possible to reduce production costs. But, varying the number of cylinders
has secondary effects, such as the torque curve, etc.

Yes, but a 4 cylinder engine with the power of a V8 might be a little
rough for many Cadillac buyers.

Cars with very large 4 cylinder engines have been built. One was built on
half of a V8. It was rough and noisy, not to mention being on the heavy
side. These days most larger in-line 4 cylinder engines have a balance
shaft to cancel out some of the secondary shaking motions.

And that would, of course, cost a pretty penny - more than a similar
displacement & output V8?

A really big 4 would be cheaper to build, all other things being equal.

I would expect that a V8 would cost more than a 4 of similar
displacement, simply based on the parts count, but what do I know.

You would be right.

The 4 would probably require some more expensive drive train parts than
the
V8, at least in manual transmission applications.

I don't know about that. For one thing, we haven't said which configuration
4 this is. IME flat 4s put out a lot of low end torque for their
displacment, and require beefed-up drive trains that can handle it. In-line
4s and V6s and V8s seem to be lower on low end torque for a given
displacement and stroke/bore, and can probably get by with less beef in the
clutch, tranny, differential, and CV joints.

Output classes A and AB
 

"Eeyore" wrote in message
...


Andre Jute wrote:

In the halflight dreamworld inhabited by Dougles Zero-sound, Poopie
Stevenson and Worthless Wiecky, SE amps would be impossible, Class A1
amps would be impossible, and all other classes would produce zero
music -- in fact all other classes would produce 100 per cent pure
noise by being operated at all sonic peaks at either max current and
zero voltage or zero current and voltage plate overvoltage. All of
that follows logically from 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.

It's actually the only accurate definition.

Agreed.

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

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

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. ;-)

You really should constrain yourself to talkind about stuff you
understand.

It would save a lot of bandwidth.

Which would seem not to be very much going by your posting history.

Jute is mostly about hyperbole. In real life he makes Walter Mitty look
like a world-class adventurer. ;-)

GM V8-6-4 (was Output classes A and AB)
 

On Thu, 25 Oct 2007 05:56:37 -0400, "Arny Krueger"
wrote:

A cylinder in a gas engine uses more energy if it is only partially in use
than if it is turned off. Some losses stay about the same, but other losses
are vastly reduced if you partially turn the cylinder off by means of
significantly altering the valve timing. AFAIK, the spark plug still fires
but no fuel is injected, and the amount of air that the cylinder pumps is
vastly reduced.

In the huge diesels that routinely turn off multiple cylinders, the
valve gear is uncoupled so the valves remain closed. That way no air
is pumped and the losses drop to negligible levels. You really don't
want to be shifting air, even if there is no combustion, if economy is
your objective.

d

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

Output classes A and AB
 

On Thu, 25 Oct 2007 06:00:25 -0400, "Arny Krueger"
wrote:


"Eeyore" wrote in message
...


Andre Jute wrote:

In the halflight dreamworld inhabited by Dougles Zero-sound, Poopie
Stevenson and Worthless Wiecky, SE amps would be impossible, Class A1
amps would be impossible, and all other classes would produce zero
music -- in fact all other classes would produce 100 per cent pure
noise by being operated at all sonic peaks at either max current and
zero voltage or zero current and voltage plate overvoltage. All of
that follows logically from 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.

It's actually the only accurate definition.

Agreed.

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

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

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. ;-)

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

Output classes A and AB
 

"Don Pearce" wrote in message
...
On Thu, 25 Oct 2007 10:26:32 +0100, Eeyore
wrote:



Andre Jute wrote:

Poopie Stevenson aka Eeyore
wrote:
John Byrns wrote:
Andre Jute wrote:

Historically, the original purpose of Class AB was to annihilate
the
second harmonic which before made up such a very large part of the
THD, while still allowing beam tubes and pentodes to give much
larger
power than available before.

Andre, why was Class AB necessary to annihilate the second harmonic,
didn't Push Pull operation already annihilate the second harmonic
irrespective of the class of operation?

Yes, you are right. It does.

The SOLE purpose of AB is to produce larger power outputs using the
same tubes.

Or bits of silicon, or whatever amplification device is being used.

Now this poor dumb slow learner Poopie Stevenson, an embarrassment to
everyone who comes into contact with him, claims to know more than the
RDH4! Yo, Poopie, in the RDH4 (Newnes 1997) on p 545 we find this
nugget of authoritative information by F. Langford-Smith B.Sc. B.E.
himself:

"Class AB operation indicates overbiased conditions, and is used only
in push-pull to balance out the even harmonics."

No such thing in the RDH4 at hand.

It's the push-pull that cancels those harmonics YOU UTTER CRETIN ! A Class
**A**
push-pull output stage will do that too.

Agreed.

AB operation has NOTHING to do with distortion cancellation.

Agreed.

Your problem is that you don't understand what you'r reading so you quote
out of
context as a result of your utter IGNORANCE.

Seems like Jute has his own private translation of the RDH4 that adds errors
to what the original authors wrote.

Graham, please just killfile the idiot like most of us have. His
dribbling meanderings are just as irritating at second hand as they
are when they have dropped fresh from his rear end.

The guy who manipulates the Jute sockpuppet is an attention-hound, pure and
simple.

GM V8-6-4 (was Output classes A and AB)
 

"Don Pearce" wrote in message
...
On Thu, 25 Oct 2007 05:56:37 -0400, "Arny Krueger"
wrote:

A cylinder in a gas engine uses more energy if it is only partially in use
than if it is turned off. Some losses stay about the same, but other
losses
are vastly reduced if you partially turn the cylinder off by means of
significantly altering the valve timing. AFAIK, the spark plug still fires
but no fuel is injected, and the amount of air that the cylinder pumps is
vastly reduced.

In the huge diesels that routinely turn off multiple cylinders, the
valve gear is uncoupled so the valves remain closed.

Thats about the same as what they do in the cars I mentioned.

That way no air
is pumped and the losses drop to negligible levels.

Agreed.

You really don't
want to be shifting air, even if there is no combustion, if economy is
your objective.

That seems to be how the technology works. I am informed by my friends who
have cars that implement this strategy, that there are consistent and
significant real-world fuel economy gains, as measured by modern car
computers that display dynamic fuel economy measures.