Class A Power in A/B amplifiers?

The old Luxkits had the A to AB switch back in the day.

Happy Listening.

There is no industry standard.  That is why discerning people (like me) buy Class A.  The standard for that is 100%.

2nd there is no standard.  In most amps in fact bias is adjustable.  What you may not realize is that its simply a trade off of heat vs "class-A-ness".  I honestly find very little difference between a truly high biased AB amp and class-A, and i can simply turn the POT.

I designed and manufactured a very high bias amp in the mid 1990s - ran class-A about 40% of its rated power (which, for heat reasons and others, was accordingly modest). The prototype remains my "daily driver" today.  Sometimes 2 in monoblock mode, but usually I'm swapping things too often to go to that level of complexity.


Given that music has a peak:average ratio of about 10, an amp that is 50W and is 5W class-A would only be out of class-A operation a small % of the time, and those times would be major crescendos when subtlety is more of less completely masked anyway.
G

Emaillists, I don't get hung up on the claims; too many times in the past they did not result in superior performance. Evey manufacturer has a claim, an angle.

It's the amp you don't see coming that blindsides you.  ;)

Fascinating thread here. OP didn’t know how loaded the question was. 
The Pass Labs designer’s write up is excellent. I don’t know where this video is at the moment, but an interview with amp designers had John Curl: the question was, “how much bias do you use?”

”As Much as I can.”

- and back to the discussion of the balancing act between too much heat & distortion and SQ/ cost.