Class A Watts

I own a Sugden A21SE and at only 30 wpc Class A it does not play louder than other well designed 30 wpc gear, but it is definitely quicker and approaches that oft elusive tube sound. The characteristics of speed, solid bass response and openness of vocals.

If your speakers are low impedance, or have an impedance curve that varies quite a bit, both current delivery and output impedance of the amp (damping factor)will have a greater effect on the sound than the amount of watts that the amp puts out.

However, there are A/B amps with no switching distortion and much quicker than lots of class A amps. Just because it's class A doesn't mean it's better than any other topology. Conceptually, it is ideal with regards to this issue. As far as tubes go, you're not going to get there without mosfets in an ss amp.

Going class A is a method of reducing distortion. In a high end amplifier that is supposed to sound like music, this can really help in a lot of cases.

Class A is not the defining criteria though. There are all kinds of design considerations that affect the way an amplifier can sound.

A watt is a watt unless you are comparing ss watts to tubes watts. Although many people feel that Class A amps sound tubish and it might hold some water but honestly I think they have their own particular sound and would definately give a favorable nod to the pure Class A designs over Class AB. I have heard some digital switching amps that come very close to the tube sound but in the end they still sound more like very good solid state.