modulation pots

[222DBFL]

I am not sure. Try a google search and see what comes up. I know that the variable is a weak link though from other Posts on other forums. Open amp up and have a look it may be a heavy duty potentiometer. I have never had a variable power like that, only ones with switches. Maybe someone with a bit more knowledge will jump in and help out. Popping the lid and looking around will help. Also another thing to look for is burnt resistors next to the inputs for the transistors. Look for any burnt resistors. If they are burnt the transistors may be bad but for what you paid, you could rebuild it for way cheaper than a new one!!