"Class A" nonsense

[Chuck H]

In a lengthy study done independently, it was found that anything "dead" doesn't seem to care, or even alter it's position either way

Dead horses play no amps. (but if they did, they would surely be class A, single ended) Considering the level of regard dead horses seem to merit I would expect no less.?.

Chuck

[Old Tele man]

How To Ride A Dead Horse

Lakota Sioux tribal wisdom says that when you discover you are riding a dead horse, the best strategy is to dismount. However, in business we often try other strategies with dead horses, including the following:

1. Buying a stronger whip.
2. Changing riders.
3. Changing to another dead horse.
4. Grimly continuing to beat the dead horse while saying things like "This is the way we always have ridden this horse."
5. Appointing a committee to study the horse.
6. Arranging to visit other sites to see how they ride dead horses.
7. Increasing the standards to ride dead horses.
8. Appointing a tiger team to revive the dead horse.
9. Creating a training session to increase our riding ability.
10. Comparing the state of dead horses in today's environment.
11. Revisiting the performance requirements for horses to determine if dead horses might not be acceptable for the immediate needs after all.
12. Changing the definition of "dead" so that the horse does not qualify under it, making the horse not "dead".
13. Hiring contractors to ride the dead horse.
14. Harnessing several dead horses together for increased speed.
15. Hiring or appointing a team of expert consulting riders to see if a highly focused team approach can get the dead horse to work better.
16. Declaring that "No horse is too dead to beat."
17. Providing additional funding to increase the horse's performance.
18. Doing a CA Study to see if contractors can ride it cheaper.
19. Purchasing a product to make dead horses run faster.
20. Declaring that the horse is actually "better, faster and cheaper" or “a better value” if it's dead.
21. Forming a quality circle to find uses for dead horses.
22. Revisiting the performance requirements for horses.
23. Saying that the horse was procured with cost as an independent variable.
24. Promoting the dead horse to a supervisory position.
25. Hiring consultants to review dead horses on other continents to see if riding dead horses can be off-shored.

.hm-m-m-m, sounds like you do a lot of government contract work (wink,wink)!

[balijukka]

(but if they did, they would surely be class A, single ended)
Chuck

Hold it there. All the horses I've seen this far - dead or alive - have two ends.
The fodder goes in from the cathode end, and the fertilizer comes out from the plate end.

jukka

[Chuck H]

and the fertilizer comes out from the plate end.

That's horse$h!t... You need two equine for push/pull operation.

Chuck

P.S.
R.G., In another study it was found that dead horses move much faster going down hill. And the steeper the grade, the faster they went.

[R.G.]

Hold it there. All the horses I've seen this far - dead or alive - have two ends.
The fodder goes in from the cathode end, and the fertilizer comes out from the plate end.

Only if you feed them electrons.

If you feed them current, it goes in the emitter and out the drain.

The Lakota Sioux were keen (!) observers of horses though. They knew, almost instinctively, that dead horses ate much, much less than undead horses, so the fodder requirements for dead horses were much lower.

[Enzo]

And as Abbott and Costello pointed out many years ago, "you've got to eat your fodder to be a good mudder."

[Alex/Tubewonder]

Alright then, I spent the last few days reading up on the subject. My conclusion is that all classic tube textbooks - I have a pretty impressive collection of original hard copies in 4 languages - are WRONG.
Class A is whatever creative advertising copywriters tell you it is. Everything else is just technobabble intended to conceal the truth from the masses. Sort of Orwellian "tubespeak".
Politically correct and safe answer - that will save you from lynching by the mob - to the question whether this or that amplifier is a class A: Read the official f***g marketing brochure.

[Old Tele man]

...what? Spangenberg, Smith (RDH), Terman, Van Der Bjils, Reich, Chaffee, Geppert, Seely, and Henney have been "lying" to us all these years?

...what would DeForest say?!?

...I'm crushed (wink,wink).

[Robert M. Martinelli]

...what? Spangenberg, Smith (RDH), Terman, Van Der Bjils, Reich, Chaffee, Geppert, Seely, and Henney have been "lying" to us all these years?

...what would DeForest say?!?

...I'm crushed (wink,wink).

Alex, OTM,
you can add ( to your already impressive list of supposed "liars" ) a good number of Italian textbooks , who lied to me too during the last 37 years ( the first textbook I was given at the age of eight was indeed dedicated to tube circuits )......

Moreover, I frankly don't understand how it can be said that the "amps' class of operation theory" doesn't apply to "guitar" amps. If they belong to the "amp" species, they have to follow the same ( electronic ) laws that rule any amp's operation.

In Italy we use to say " there's no worse deaf than the one that's not willing to hear", which fits perfectly what happened here IMHO.

This will be my last post on this matter, I'd like this poor horse to finally R.I.P.

Cheers

Bob

[imaradiostar]

Perhaps we can agree on this:

-cathode biased push-pull amps tend to bias themselves colder as output approaches clipping. This effect combined with a slightly sagging power supply can cause a push-pull class A amp to begin to operate in class AB.

-fixed bias amps can be biased (given regulated plate, screen and bias supplies) to be class A or AB regardless of the input signal and up to their rated output. If overdriven they will clip and all of the definitions become murky but it won't change operating point set at the rated power input and output. This also ignores the idea that you could drive the grids really hard and charge up the coupling caps during grid conduction, forcing the tubes to be biased colder.

-If I'm not mistaken a true class A single ended audio amp will draw less current while clipping hard than at idle...which could be seen as class C operation (good call, that's funny) but either way it's fair to say it's a clipper!

As for the class A thing- we're not going to (and really don't have to) convince people that their AC30 or Matchless isn't class A. As long as it goes "KRANG!!" when they play their cowboy chords they'll be happy. I have many dear friends with excellent ears that don't care what you call it, they just love that sound and make excellent music with it.

jamie

[Old Tele man]

...'Class-A vs. Class-AB' is to musicians as 'Pluto-the-planet vs. Pluto-the-planetoid' is to astronomers--nobody agrees, even though the decision has already been made (years ago).

...and the decison HAS been made.

[balijukka]

...and the decison HAS been made.

You just keep evading, circling around and claiming things without the slightest backing.

Who has made the decision, and when ?
What is the decision?
Or is it just your dream of reborn horses ?

jukka

[Old Tele man]

...if you don't like what you HEAR, don't LISTEN.

...if you don't like what you READ, don't READ.

...but, don't expect OTHERS to flock to your OPINION.

...I prefer the comfort and backing of following established CONVENTION, rather than trying to REINVENT my own.

...I didn't establish the CONVENTION, merely explained it in my words, which apparently you take exception to...your perrogative.

...Class-A is defined as 360° plate conduction. How do you verify this condition? By "testing" at maximum power output, not at idle, because at idle there's NO input signal. And, what defines "maximum" power? The power "claimed" by the circuits designer, it's "rated" output. Since, there's always distortion in the mix, how "close" to clipping and saturation can that maximum power be pushed and still be acceptable, by CONVENTION? That was established by the human ear and engineers long before I was born...at a value of 5%THD or less. It's a distributed answer.

...if you don't like what you READ, don't READ it.

[balijukka]

...if you don't like what you HEAR, don't LISTEN.

...I prefer the comfort and backing of following established CONVENTION, rather than trying to REINVENT my own.

...I didn't establish the CONVENTION, merely explained it in my words, which apparently you take exception to...your perrogative.

First you come out preaching that IEA rules say this and that, then you could not show these IEA rules, and now you're quoting established convention. Soon it'll be some holy script that only the annointed are able to understand.
Somehow this reminds me of the church in Rome trying to silence poor Galilei.

...Class-A is defined as 360° plate conduction. How do you verify this condition? By "testing" at maximum power output, not at idle, because at idle there's NO input signal.

The amps are like the real world, not black and white. There is a very big grey zone between the idle and maximum output, and it happens that it is the one most used.

Individual thinking and free expression are the roads to enlightment, but as all the preachers know, if you keep shouting out loud, very few people would bother to raise a voice. And perhapr even the dead horses will resurrect.

jukka

[Steve Conner]

Keep it civil please folks