mikeh wrote:

"Charles Schuler" wrote:
"mikeh" wrote

Push-pull amplifiers can suffer from crossover distortion. It is a bias
issue ... some modest forward bias is required to reduce this distortion. A
simple check: is the distortion much worse at low volume levels? If yes,
then it is probably crossover distortion and you will have to investigate
the forward bias circuit for the output transistors. If no, then it could
be any number of things such as a bad electrolytic capacitor, a transistor,
and so on. Not an easy one to fix, by the way.

Thanks, distortion is just as bad at all volume levels. And at all
outputs too: there's a headphone, L/R Hi-Z and L/R XLR. Sounds like
this one might be a bear.

No, it's simple. Find where the volts are dropping.


Graham