Paulie, it sounds like you have an arcing problem somewhere, it could be a tube socket, inside a resistor, inside one of the transformers, it could be in a few other things, the safe bet is to have it checked out as soon as possible, and do not play it until you have it checked out, one small component can sometimes take other larger, more costly components with it when it fails, so play it safe, also when you find out what it is, please post again and let us know what the problem was, you might help someone else out with a similar problem, Good Luck