I'm new on the forums, so forgive me if I'm posting this in the wrong area. Below is kind of a block of text with a little more detail, so here's the short version: I heard a pop come from the head (not the speakers) followed by a sizzle, then shorty after an electrical smell. It still works. Am I dealing with a blown tube? or something else here? Any help or insight would be appreciated. Thanks in advance to any replies. /start back story I got lucky with finding a 70's SVT with the original Magnavox "branded" tubes still in it. (back from when they owned ampeg) From what i was told, it was gigged with for about a year when it was bought by the sellers father. After that, it sat for years moving from garage, to closet. They said it had been serviced, but i kind of doubt it judging by the amount of dust it had inside when I got it. /end back story What happened last night: All channels and inputs work great, loaded up, headed to rehearsal. Unloaded, set up, power on *stand-by*, got a drink and gave it a bit. Played for half an hour, band took a break, and I turned down and kept playing. I pause for a bit, and all of a sudden, I hear a pop come from the head, not the speakers, followed by a sizzle. I was hoping the noise had came from elsewhere, but then i started to smell an odd electrical burn with a bit more nasty to it. I threw the amp in stand by for a few, and turned it off. 10 minutes later, i power it back up, give it a few, take it out of stand by and start to play. I didn't check each channel or input, but nothing appeared to have audibly changed. The smell however was still there. (*one note, I'm running a Morley A/B/Y to channel one bright, channel 2 normal.) I took the cover off to take a look, and all the tubes still had the dim orange glow, equal intensity from what i could tell. Back to standby/power off. I didn't get to mess with it much more than that, and don't want to further damage anything if i can avoid it. I left it at the rehearsal space, unplugged. So here I am. Any guess as to what I'm dealing with? Blown tube? Something worse? If I remember right, these amps tend to keep going without much loss if a tube goes out. Any help or insight would be appreciated. Thanks in advance to any replies.