‘67 Dual Showman Buzzzz

[fdesalvo]

All grounds intact. All pot and jack mating surfaces are clean. Only speaker cable plugged in.

Sound file attached. Ty!

[nosaj]

For some reason I can't get the sound file.
nosaj

[fdesalvo]

Try this: https://on.soundcloud.com/uXTt113nmrLLhaBv8

[nosaj]

What light is over your bench? An is the chassis open? if not put it in cabinet and lets see what you get. To me it sound like the buzz I get with certain flourescent lights in my shed.
Also have you tried the amp at another location ?
nosaj

[Helmholtz]

All grounds intact.

Did you follow up to the mains plug?

[fdesalvo]

I followed up the the mains ground too.

I have LED and incandescent lights at the bench. It makes the same
noise in other rooms of the house too. Owner has the head shell.

I appreciate you all weighing in.

[fdesalvo]

I forgot to close this out. Apologies. Found 1k resistors making up the heater’s artificial ct!

[nosaj]

I forgot to close this out. Apologies. Found 1k resistors making up the heater’s artificial ct!

1k vs 100ohm

Interesting effect.
nosaj

[fdesalvo]

A humbling oversight on my part. But it came in handy, as lightning struck twice. I was given a load of prototype and classic fender amps to restore from the new owner of *isson Amps. I was working on an old proto today that had the same issue lol. I suppose he had the magic dust and knew how to make them work.

1k vs 100ohm

Interesting effect.
nosaj