Why would anyone want class AB amp when class A always sounds better ?

"...that’s an engineering problem..."

Are class A amplifiers significantly harder to engineer, or they are about the same but only bring some of the well-known things (heat) with them simply because of class?

Also, how does efficiency of class-A amplifiers compare with other classes (ballpark figures)?

Dear @inna  : After all those posts you already know that class A not always sounds better.

Some of the posts said that depends of amps design and I add quality excecution to that design. I have this first hand experiences with Mark Levinson amplifiers:

its first amplifier named by them Reference ( and this is not a marketing name/model, when ML says that it's because it's a true reference and not MK like other products. ) were the model 20 pure class A monoblocks.
Years latter they puts in the market the new class AB model 23 and things were that the 23 outperformed the Reference 20s.

ML inmediatly took the problem and fixed with a modification in the 20s and then born the new Reference 20.5 but even with that experience Levinson again puts a new class AB amp in the market that was the 23.5 and wonder what: again the 23.5 outperformed the 20.5s and Levinson had to fix it and did it through the Reference 20.6s.

I still own the 20.6 with some modifications by my self and a friend of mine and owned the 23 and 23.5.

What made Levinson in his pure class A Reference 20 and latter in the 20.5?   , they don't touch the output whole design but made the changes ( twice ) at the input design at the input circuit boards and through those changes the 20.6 outperformed the 23.5. Even that the 23.5 was very good class AB amplifier.

Theshold had the class  A SA-1 monobloks and at the same time Pass designed the class AB S500e.
I listened both models several times and the class AB was a better performer.

Crossover distortion not always makes the difference for the better. Design and excecution quality level to that design is really what it counts, it does not really matters if class A or class AB.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Class A,
class A/AB
class H

all sound great!

Why so many mean people?

My class H is the Carver Sunfire 600. Pretty sure it’s class H.
She sounds great, pretty much unlimited power with that amp!
Clean, open, great sound on all spectrums , bass, mids and treble are all superb!

I especially love both taps, and switch quite often, depending the music I listen to.

The tube sound tap, is great, makes my listening very enjoyable.

If you love the sound o your amps no matter where they rate in class, a, a/b, h, d.

Listen and enjoy.

Are class A amplifiers significantly harder to engineer, or they are about the same but only bring some of the well-known things (heat) with them simply because of class?

Also, how does efficiency of class-A amplifiers compare with other classes (ballpark figures)?

They are not harder to engineer. Its arguable that they are a bit easier, although you have to be more careful about heat issues and the power supply has to be able to support the output section being on all the time, something that you don't get with AB amps.

Of course class A is the least efficient of all classes of operation. The advantage is the output devices are often biased at the most linear portion of their curve. So if all goes well, they will make the least distortion.