[Dalberg-Acton]

I've read you can revive old tube equipment that has set a long time with a variable transformer. To slowly raise the voltage so the caps don't blow.

[dayglored]

Yep, done that too, But my old Variac isn’t as pretty as that one, though — I scrounged it from a rack panel in a MIL surplus store. The windings are all open, so you have to be real careful handling it. But then, you can see how it works :-)