Thank you.
Yes you need new boards on those as they ran the output tubes to hell and back, therefore generating a lot of heat cooking the old boards.
Today's boards are quite good: those are 1.6 mm thick, 2 Oz copper thick, lead free with double layers. glass epoxy rated to 140C.
I added a hole at the bottom of each tube for heat ventilation.
Those with Dave's changes will make the amp run forever.
You should have bought one, they sound marvelous
Yes you need new boards on those as they ran the output tubes to hell and back, therefore generating a lot of heat cooking the old boards.
Today's boards are quite good: those are 1.6 mm thick, 2 Oz copper thick, lead free with double layers. glass epoxy rated to 140C.
I added a hole at the bottom of each tube for heat ventilation.
Those with Dave's changes will make the amp run forever.
You should have bought one, they sound marvelous