Class A Power in A/B amplifiers?

There is no standard. The amount of class A can vary from less than a watt to a couple of watts and sometimes more.

Note that the class A rating is usually for a solid state amp at 8 ohms. It's less as the impedance drops.

Also note that most class A amps are really very rich class AB amps where the rating is just the class A rating and they produce more power but in AB. As an example PASS makes 30 watt amps that are rated at 30 watts class A but often produce more than twice as many watts in AB so almost all the time they are in A but on peaks they go to AB.

As implied previously most class A amps that really are class A into 8 ohms are not as the load impedance drops. The only one I'm reasonably sure was is the old Mark Levinson ML2 which was rated at 25 watts class A and was still class A at 100 watts into 2 ohms.

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.  ;)