Why do I like Class AB better than Class A?


So I just purchased a Plinius SA 100 MKIII, and have had 2 listening sessions comparing both with the toggle switch. To me clearly the AB is more detailed and focused, the A is warm but a little fuzzy and bloated, although I would give it a slight nod on just vocal songs. Am I just not use to the sound as this is my first A amp or have I not let it properly warm up for class A (1hour or so).
Don't get me wrong, i love the amp, great bottom end slam but I don't hear the holy grail from Class A. Thanks in advance for the input guys.
barfbag
Interesting, I'm wondering if there may be something wrong with the amp. I've owned 3 Class A amps, but only one of them had the ability to switch between Class A and AB, and even that wasn't a pure Class AB, it was more of a Class A/AB. That amp was a pair of Clayton Audio M-100 monoblocks. Anyway, I love Class A sound, it is amongst the best SS I have heard. On the Clayton amp I had the ability to switch from high bias (Pure Class A) to low bias (Class A/AB) and found that while low bias may have had a slight edge in dynamics, high bias provided a greater sense of liquidity and ease. The sound became more relaxed and natural. I would NOT say it became fuzzy or bloated at all.
What speakers are you using?

Perhaps what you are comparing is the difference in power and not just Class of operation.

Maybe the speakers are just too power hungry for the Class A's limited output to shine.
Doogie - there is no difference in maximum power output in "Class A" or A/B its just a matter of how much bias current there is running in the output stage at idle The term "pure Class A" is a bit of a misnomer too as a speaker load is far form flat, a push pull amplifier biased for 50 Watts class A into a 8 ohm load would only "have" 25 watts of class A into a 4 ohm load although depending on rail voltage it would have a maximum power output of lets say 100 Watts into the 8 ohm load and a whopping 200 Watts into a 4 ohm load.

Nelson Pass wrote a very informative paper on this subject called "Leaving class A " it can be found on his website.

On my own amplifiers I have a built in the option to select High bias or Low bias I prefer the sound in High Bias but if just for background listening I leave them in low bias, no need to use up all that energy.

Good Listening All

Peter
Correction,

"although depending on rail voltage it would have a maximum" should be

"could have"
I am pretty sure the SA-103 (the replacement of the 100) and the SA-Reference that I have has a much lower output in Class A. 100W vs 300W in AB.