#5783
Paul
Participant

I think I can closeout this thread by saying after adding a standby/Pentode/triode switch, I inadvertently found the wire that was the cause of hum.

adding the switch added a tone of hum, but moving it (and its many attached leads) about three mm made the big hum go down to virtually nothing .

the only noise you hear now is a tiny bit of hiss and only when cranked .

thanks all!