Actually difference between class A and AB?


Class A amp sounds like holy grail of HIFI world.
But class A amp are much heavier, more expensive and rarer than class AB or class B design. Few can afford 100 LB weight of a 2-channel 100w/c amp.

Is there any actual difference between class A and class AB when listening to actual music? And what is that difference?
hl10027
I find that class A amplifiers play bass better as well as being smoother in the mids and highs. They can also be more detailed as they make less distortion.

BTW/FWIW there is no such thing as A/AB. That would simply be an AB amplifier. If you see such designations they are marketing terms, not technical terms.
Athmosphere,

Not quite, the nomenclature A/AB simply denotes that the amplifier operates in Class A up to a certain power level then switches over to Class B. This switch point is determined by the bias.

http://www.passlabs.com/pdfs/articles/leaving_class_a.pdf
Liguy, I have to disagree, despite Nelson's paper. The designation of 'AB' **already** "denotes that the amplifier operates in Class A up to a certain power level then switches over to Class B. This switch point is determined by the bias.", as you put it above.

IOW, Class AB already meant this; it could be class A to 0.5 watts or class A to 35 watts with clipping at 40 watts, either way that is what AB is... Putting another 'A' in front of it thus has no meaning, and is not found in the textbooks. That's why I say its a marketing term.
The Latest issue of The Absolute Sound has an artical that goes through all the different types of amps.
Just got it yesterday, have not read the whole artical yet. Looks like it has some good infromation in it.
Joe Nies
Newer Class Ds done well may be the emerging holy grail for most in terms of overall performance, efficiency, and cost of ownership. Maybe even just on performance alone, the rest aside.

I am not a Class A/B fan anymore in general.

Class A is good but practical for most only in certain cases.

I've had older Class G rail switching amps also. Those were smaller and more efficient also but also very mediocre with a compromised design, like much Class A/B perhaps.