I don't see anything wrong.
Maybe there was a whisker wire that burnt up.
The diodes can be on pin 1 or straight to ground as long as pins 1-8 are tied together then to ground.
The blue Center Tap wire of the OT is going to the standby switch yes?
Mark
New Express build!!! Some troubleshooting required.
Moderators: pompeiisneaks, Colossal
Re: New Express build!!! Some troubleshooting required.
Yes, blue CT to standby. I’ve got the replacement tube socket in but am now away for a week so further testing when I get back. Thanks again for the input guys
Re: New Express build!!! Some troubleshooting required.
I built a 50 watt plexi amp a while back.. Brand new tubes {tungsol EL34} Fired the amp up, and it smoked the socket in an instant,had to replace the socket.. Bad tube right out of the box. suppose to have been a tested matched pair bla bla.. If you replace the socket, be sure to put in a "known" good set of test tubes.
Re: New Express build!!! Some troubleshooting required.
Sounds like you may have touched both pins 2 & 3 simultaneously. This triggers an arc. I did it once and it blew the heater-to-ground virtual CT resistors. Sounds like your arc self perpetuated via the carbon.
If it says "Vintage" on it, -it isn't.