Hey UG, my friend just bough a Peavy 6505 today that was used but something odd happens with it. He can play it for a while but then sometimes when he stops playing, it sounds almost like a firework about to go off where the tubs are. Is this the tubes or something else, and if so, what can he do to fix it?

Thanks in advance.
Alright. We noticed that the more he played, the longer it would take for it to start happening again, I was thinking maybe the tubes didnt get warmed up all the way since they hadn't been played in a long time.
See it has a standby button, and one way or another we left it off I think. We had waited 3 minutes before he played it but maybe if the standby wasnt on then it didnt matter since the amp wasnt really on. I dont think he blew a tube, I checked the back and the were all lit up and everything.