Thoughts on restoring a Dynaco ST70

[Schmidlapper]

PIO1980 told me easiest access to cathode voltage is at the two axial caps nearest the front, at the most central leads to ground.

 

[Schmidlapper]

I presently installed fixed 820K screen resisters and then was able to find two 6GH8s that both measure ~ 24% on cathode voltage. This will tide me over until I add in variable resisters one day to be more flexible regarding tubes.

 

[radu_c]

I presently installed fixed 820K screen resisters and then was able to find two 6GH8s that both measure ~ 24% on cathode voltage. This will tide me over until I add in variable resisters one day to be more flexible regarding tubes.

I made a spare set of these adapters that have 15mm pin spacing (which fits in place of the old resistor) and takes a standard trimmer footprint with 2.54mm pin spacing. If you're interested PM me and I'll send you the spare.