So I recently bought a Fender '65 Twin Reverb and when I got it home it developed problems. I took it back and the shop told me it was probably the tubes. they swapped out the tubes and it seemed to work fine until I got it home and cranked it up....more problems. I took it back again and the Fender Rep happened to be in the store and offered to order me a BRAND NEW Twin. I wited three weeks for it to arrive and I got it home and left it sitting in the box for several days, because I was hoping to trade it. Well...tonight I decided to play it. At low volume it sounded fine but when I cranked it up to "5", it started crackling very loudly and one of the 6L6s was glowing red hot (It wasn't before) Now, I'm faced with having to get this one fixed under warranty I guess but truthfully I have no faith in these at all and I'd rather Fender give me something else. I haven't tried to contact them directly yet,as it just happened tonight. So..... Can anyone give any insight as to what the problem could be? Should I swap the tubes around to see if it's a bad tube before I do anything else?