Class A amps

We no understand black hole or why woman trying to make conversation with me at the gym but we know everyone brain wired to like something best. All blonde and brunette like me equal but me thinks ear and speaker prefer certain topology best.

Class A amps

I’ve read a few articles on class A amps but still don’t have a good understanding of how it affects sound quality.

One simple thing, zero cross over distortion, changing from class-a to class-b .
A great designed class-A solid state cannot be bettered

If you patient read this
https://www.firstwatt.com/pdf/art_a40.pdf

Cheers George

Folks, just so you know, one reason there is class AB is so that there will be no crossover distortion, as opposed to class B where this is a problem (and usually class B amps are not intended for hifi operation on this account). The amp is biased just enough so that it has an operating point in the A region (at idle) so crossover distortion due to cutoff of the output devices is simply not possible.  Whether you're class A to 1 watt or full power isn't going to make any difference insofar as crossover distortion is concerned.


However you do get better distortion cancellation when the amp is class A to full power and hopefully the output devices are being operated in their most linear region.


The reason to do this is that most solid state amps made in the last 70 years don't run enough feedback to really do the job that needs to be done, so to help the amp make less distortion to begin with its set up to run class A. Put another way this reduces distortion when the amp is running open loop; thus the feedback has less work to do cleaning things up.

There are two types of solid state class-A
Complimentary push/pull solid state amps that can be class-a/b or class-a if biased to the max so neither of the push pull transistor "ever" switch off and give crossover distortion. If they did you’d have crossover distortion
Or Class-A that uses a constant current source and the bottom instead of complimentary push pull arrangement, and never gives cross over distortion

When a class-a/b amp leaves it’s biased level of class-a and enters class-B then there is cross over distortion.
Only an amp that is biased hard all the way in class-a avoids this.

This "one" of the very best amps push pull solid state that was hard biased into pure class-a, it was the massive and maxed out doing only 25watt @ 8ohm, the Classic Mark Levinson ML2 monoblocks, but they could do almost 200w into 1ohm they were so good at giving current
https://img.usaudiomart.com/uploads/large/2229206-5c605986-mark-levinson-ml2.jpg

Nelson Pass on Class-A and crossover distortion:
In class AB, this effect is "alleviated" by a small bias current, and then is eliminated in class A where the bias current is high.
As he says crossover distortion it's alleviated in A/B with some bias but not eliminated, that only happens in Class-A amps



Cheers George