The other thread ended with Q8 catching on fire and no resolution. It's better if you just tell us what is going on with your amp.
You can monitor the voltage across R97 (one probe at each end). If you see more than 5VDC, stop. As you move the variac voltages may jump around so give it a couple seconds to stabilize.
Also keep checking for DC at amp output.
If you are seeing low current on the variac meter, you should be ok to raise the voltage.
You can monitor the voltage across R97 (one probe at each end). If you see more than 5VDC, stop. As you move the variac voltages may jump around so give it a couple seconds to stabilize.
Also keep checking for DC at amp output.
If you are seeing low current on the variac meter, you should be ok to raise the voltage.