Hi All. Wondering if you could help me diagnose an issue with my AC4TV, and please forgive my lack of technical knowledge here. I was playing the amp when all of a sudden the tone turned highly distorted for a minute and then the sound just cut out. This was then followed by an electrical burning smell. After I detected the smell I immediately shut off the amp. I left it for a few hours and then powered it up again to try it, and there was still no sound, and hasn’t been since that incident. So I was initially thinking given the burning smell that I may have fried the OT, but after Googling it seems it could potentially just be a tube giving out. If it is a tube I assume it’s more likely to be the EL84 rather than the 12AX7 in the amp, right? I don’t have a spare EL84 at home right now (other than pulling one from another amp) to try, but if I get a spare to try out the amp doesn’t need a bias does it? I can just swap the EL84 out? Any assistance or advice would be appreciated.