Accustic Arts Power 1 - operates in Class A?

Kijanki, I just recently read a thread on this very subject on DIY. This discussion revolved mainly around BJT outputs and there was an unanswered question regarding mosfets. However, in applying this school of thought, I'm perceiving a sonic difference when backing off the stock 300ma bias setting in my Acoustat TNT200 mosfet amps. Can you please elaborate on this? Thank you.

I guess my question is whether the same principals apply or am I hearing things?

Thank you, Elizabeth. But my question is not whether it's class A. I already know it's A/B. I was questioning whether(optimal bias) as regards BJT outputs applies to mosfets.

To the best of my knowledge (as I recall speaking to the people in Germany), their top of the line amps are biased for a few watts in pure class A. Your lack of additional wattage draw registration from your PS Audio is due to the amps' massive storage energy bank, and perhaps the relatively benign load of your speakers. Just my two cents.

Best regards.

Csontos, I don't know. Things I've read apply to bipolars only. In my opinion it should also apply to Mosfets but design might be completely different possibly equalizing gain. Assuming that overbiasing of Mosfets might reduce distortions the question would be "by how much". The main problem I see with class AB is that because of inherent nonlinearities feedback is usually 10x deeper than one in class A amps. This feedback might create odd order harmonics because of Transient Intermodulation. Once you have this feedback set in your amp by design changing bias won't help TIM. Your improvement in distortions might be miniscule and not worth the heat dissipated not to mention possibility of increased distortions if we got it wrong. Increasing bias current and heatsink size seems to be inexpensive proposition and if designer decided against it I wouldn't touch it.