V-M 160 vintage tube amp servicing

This is an old square dancing dual-channel tube amp from the 50's. It's got one channel for a record player and one for a microphone for the caller. It had some really bad hum problems.

(click for full size)

(click for full size)

Luckily it came with a schematic inside. If only consumer electronics were like that these days.

(click for full size)

It looks pretty gnarly inside but everything, including the stacked capacity bank, seem to be functioning. I ended up replacing the power cord with a three-pronger and grounding the chassing. Most of the hum is now gone. It's a great clean amp but hard to get any distortion out of it.

Here is a recording of this amp with a telecaster.