On Tuesday, November 24, 2015 at 6:10:30 PM UTC-5, wrote:
Put a scope on the outputs and look for very high frequency harmonics. Perhaps the system is working too hard on things you can not hear.

Dan

good point


logical seteps
is it actually getting hot?
if not, the thermal shutdown system could be faulty

if it is getting hot you need to figure out why....
there could be an ultrasonic oscilation in the amp
the quiescent bias current could be too high in the amp
there could be some kind of short or overload at the output of the amp, bad speaker?

have fun , fixing stuff is a great way to learn

Mark