The failure was pretty spectacular, but I was too concerned about shutting it off before it actually blew up to take a picture. It started glowing very bright, blue, and buzzing loudly. The front right power tube. Time to add hunting for EL34 matched quads, or at least a pair, to my list of things to do tomorrow. The one really good place for them is closed on Sunday’s, so maybe I’ll wait till my next chance to get there when they’re open. They have matched quads of JJs for $44. Probably not amazing tubes, but this is the borrowed ST70, I’m saving my good tube money for my own ST70, whenever I start that project.