New Express build!!! Some troubleshooting required.

[M Fowler]

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

[Herzog]

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

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

[Richie]

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.

[jjman]

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.