I have a Plinius that can run in class A up to 250w/ch. It runs so hot that I think I’m shortening it’s life considerably, so I am usually in the AB mode on the bias selector. I have a hard time hearing a measurable difference through my BW 801s. Curious if others hear a measurable difference running in pure class A
250Watts class A, you can probably cook–no burn your dinner on it.
When you switch to AB, where does it leave class A?
30 Watts
30 watts is still a fair bit of class A, I would leave it there. Depending on your speakers and listening volume you may not be using much more than 30 watts albeit for transient peaks.
My wag is that at normal listening levels, you probably never get out of class A if it’s biased to 30 watts, depending on speaker load, etc.
I use a class G amp which gives a little over 20Wpc in pure class A mode. I have done the calculations based on speaker SPL, distance to listening chair, and normal listening level and even for 20db transients I am still in the 20W region. This would not hold if I were blasting out music for a noisy party but not only am I too old for that sort of party but the fidelity requirements at such a party are not very exacting.
My experience is that heavily class A biased amps are much better sounding in highs (refined, smooth), bass (harmonic structure) and thereof influenced also in mids from start.
However if their performance in transparency, prat, bass control and soundstaging can compete with other less A biased amps depends on the rest of their design.
Thank you for the responses
I recently built the Pass amp camp amp, a single gain stage Class A with 8 Watts a channel. I have to say it’s a sweet sound, though not loud on 89 dB speakers. But a very natural sound. On the other hand, I recently tried a Musical Fidelity 2Mi, which claims to operate in Class A, then AB, but I found it too bright, .so I’m sure that like most things, it depends on the maker.
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