I just finished a 5E3 build and tested voltages with no tubes. Voltages were good. I plugged in the rectifier tube and the first 25uf 25v capacitor blew up. I can't see anything wrong. However, when I was checking components for continuity to ground I noticed the 6.3v heater pins have continuity to ground. I checked the lamp holder and the two lugs on the lamp holder have continuity to ground. Is that normal for a 5E3 circuit. Any ideas why the cap would blow up? I checked the orientation of the cap and that was correct. I tried attaching photos but got error message file was to large. The wiring diagram and schematic I used are the ones from Fender. Thanks
The 6.3V coils in the PT have very low resistance, commonly about 0.4 ohms. This indeed can result in a multimeter to show continuity. You said the voltages were good, does this include the 6.3 volts?
The cap blowing up could be due to a short ,or indeed wiring in reverse polarity such that it shorted. Less likely, could also be an old bad cap.
You said "the first" but from which direction? Do you mean V1?
NEver mind you said 6V6 bypass cap... Thanks
BTW, your filament wiring is pretty random. Should be twisted pair to cancel hum, and run either against the chassis and out of the way of other wires or "flown" well above the tube sockets also away from other wires. And not wrapper around tube sockets. Running them separately though other wiring invites noise and oscillation problems. Refer to Merlin:
https://www.valvewizard.co.uk/heater.html
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