Well, Herb, here is waht you need. Takes all the work out of the bias issue.

https://www.eurotubes.com/store/pc/bias%20probes.htm

I have a Deluxe Reverb style amp I built some years ago. I made some mistakes with the Tolex cover and the grill cloth. I decided to fix it today. After putting the amp back together it has a hum. I knocked something around I guess.

I never really was 100% happy with the sound so I guess this the time to rework the amp.

Most of these tube amps are only really useful for playing on stage. Not so mant are good recording amps.

Billy