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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

Showing 2 responses by jmcgrogan2

jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
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.
jmcgrogan2's avatar
jmcgrogan2
6,346 posts
 
Minor1, there are some amps out there that have a switch between high bias (Class A) and low bias (Class AB). The OP's Plinius SA-100 mk III is one such of these amps. Clayton Audio also had amps that used to do this. There may also be others that I'm not aware of. So you have the ability to switch between Class A operation and Class AB operation via a switch on the amplifier.

To answer your question: Compared both what?
He compared both forms of operation (A vs AB) that his amp is capable of. Yes, there are other forms of operation such as Class D, also.
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