I've posted here before for help maintaining a '57 Rickenbacker M8-E (it's basically a Champ copy). About a year ago I replaced all the elctrolytic capacitors. The amp has not seen much use since then, but lately I've been practicing with it a lot. It got through several practice sessions fine, then one day the fuse blew. It was original, so I dropped in another and that blew. I thought perhaps the tubes were the culprit. I put in a known good 5Y3 and 6V6, turned the amp on and it seemed to be happy. I suspected the original 5Y3 was the one to blame, simply because it's first in the power chain, so I put back the original 6V6 and turned the amp on once more. Everything seemed fine for a couple minutes, then I started to hear this crackling or melting sound. I quickly turned the amp off. The sound seemed to be coming from the power transformer. THe PT was also quite warm to the touch. No other signs of damage are visible anywhere. So, before I totally destroy this thing, does anyone have some suggestions on troubleshooting this issue?