The earth, draped in sound. I can dig it.
Top off so we can see what's under the hood. From lower left moving to far right: 6SJ7, 6SF5, 6N7 (doing phase splitter duties), a pair of 6L6 outputs & a 5U4 rectifier.
I baked this amp a few years back. It had been sitting in a damp basement and I wanted to insure the transformers did not contain moisture prior to my attempt at burn in. I want to say it went into red plate, or oscillation. The fact that I cannot recall pretty much nullifies all my prior attention. Looks like either the temperature was a touch high or there was some sort of residue on the metal.
Pretty rainbow colors.
Seems like another amp that predates twisted pairs. I guess it hails from the era in which low enough gain, or short enough bandwidth, made such steps unnecessary. I'll probably leave this one be, unless it proves problematic, unlike some others. Nothing remarkable here, though I do like the primitive (very DIY friendly) approach to tag board construction.
If this was a class, I would offer up this modified schematic (very thoughtful, thank you previous owner!) and the following picture and request theories as to what and why.
Aw, what the hell..