[sdiy] tube phono (a little OT)

[media at mail1.nai.net]

At 3:36 PM -0500 02/10/02, Gavin Russom wrote:
>
>A friend and I are trying to repair an old tube phonograph with a built in
>speaker.  It hums loud!  Sounds to me like a grounding problem... The hum
>doesn't change volume when you turn the volume pot.  I do ok with analog
>synth DIY and troubleshooting, repairs as well.  Any suggestions? Am I in
>over my head with this one?

I'd check the filter caps in the power supply.  It's a typical problem with
old tube amps.