Should I buy a Class A Amp.

Most Pass Labs amps are also high biased A/B amps, and yes if you were to play a piece of music that was very mellow like slow blues, some Class A/B amps may stay in Class A. But maybe with a full blown orchestra that same amp may go into class B.
Also an A/B amp may stay in Class A  if the speakers impedance stays at say 8ohms, but if that same speaker dips to 1,2,,3 or 4ohms somewhere in it's impedance curve then that same amp may go into class b.

Cheers George      

I was a Krell dealer and also a Musical Fidelity in the days when use to have big amps like the 270 and 370 which were class A. The ones I liked best were a pair of Stax 100 watt As through Quad 63s. I don't have any As now and find good ABs sound good are more flexible and far less trouble. I am using a CJ 350 and Gamut D200 which are not cheap but I got the Gamut for less than a good Class A

I had a KSA 200 and it sounded good and would be good for power lifting practice. But check out the cost of new caps. I knew someone who had one and had not had it recaped because of the cost. There were many mono amps some of which were very expensive and forklift ready.

I have had a KSA80 for ten years and if it cost  seven million dollars to recap I would rob a bank .. what ever it took.

There is not a class D amp  in existence that can compare to a good class A amplifier,  and if you hear a state of the art class A amplifier, there is no turning back! 😎