I'm working on converting an Epiphone Valve Junior into a handwired 5F1 Champ with a solid state rectifier (as I'm trying to reuse the existing transformers). During the initial startup/testing procedure, everything checked out OK without tubes and then with only the 12AX7. Finally, when I popped in the 6V6 and brought the variac up to full voltage, I saw a puff of smoke. (Unfortunately, I moved to shut off the amp so fast that I wasn't able to discern where exactly it came from). Now, I'm getting a loud hum, which initially led me to believe the issue was 120Hz hum from the power section or a grounding issue. After hours of poking and prodding, the only thing that I can find wrong is the output transformer. I'm measuring about 500 Ohms on the primary, about 1 Ohm on the 4 Ohm secondary and 1.8 Ohms on the 8 Ohm secondary. I know the DC resistance is a bit less than the AC impedance, but it shouldn't be THIS low. Right?!? Before I buy another OT, is there anything else obvious that I should be investigating? I'm not quite sure what was wrong in the first place and I'd hate to blow up another transformer.