Class A Power in A/B amplifiers?


Is there a general industry standard for the amount of Class A power in Class A/B amplifiers?For instance SimAudio has always touted that they run Class A for the first 5 watts.Curious how other higher end manufacturers approach this..
freediver
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. 
It's the amp you don't see coming that blindsides you. ;)


That's just the honeymoon period.
My Krell K-300i has Class A for the first 90 of 150 at 8 Ohm.
My CODA #8 Version 1 is the first 18