GM D9605 Pioneer

[Hexhclass]

The sub channel on this amp sound distort.Drive signal going the the output FETs don’t look good.

Any suggestions?

 

[Perry Babin]

Does it produce a clean output, clipping symmetrically at the rails, with no load?

 

[Hexhclass]

When it is cold I drive a 60hz in and the signal on the output terminal looks like a saw tooth wave form.When it gets warm the drive on the output gates starts looking good and the signal on the output terminal starts clipping at the same point.

First pic output terminal when cold

 

[Perry Babin]

Can you use heating/cooling to find the fault?