That time I wired my first amp backwards and nearly fried it

I was in my garage about 3 months ago working on a little 5-watt Champ clone kit. I had everything laid out on the bench, double checked the schematic maybe 5 times. When I fired it up for the first time, I heard this loud hum and then smoke started coming from the power resistor. I killed the power so fast I nearly knocked the amp off the table. Turned out I had the rectifier tube wired with the polarity swapped, which dumped AC right into the filter caps. After I let everything sit for a day to discharge, I re-did that whole section and it worked fine. No permanent damage luckily, but it scared me pretty good. Has anyone else had a brain fart like that on a build where you just stared at the schematic and still got it wrong?

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black.margaret9d ago

Oh man, that humming sound is the worst. I did something similar on my first build, a little Fender Princeton. I mixed up the heater wires and actually put them on the output tube plate pins. The tube started glowing bright orange and I thought I was about to have a real fire. Did you end up checking all the solder joints after you fixed the polarity, or did you just fire it up again and hope for the best?