2. amps-preamps
  3. 184230-174083

What would cause noise (ground noise?) when touching the volume control and tone controls?

I have a new preamp that I recently hooked up and I'm getting some interference or what may be ground noise but I only hear it when I'm physically touching the metal volume knob and tone controls.  When I touch the metal top of the case in addition to the knobs, the noise will subside.  Just looking for ideas to help isolate the cause.  I think the case itself just isn't grounded sufficiently.

I have tried new power cables, RCA cables and plugging into different outlets with no change.

tubeguy76

Showing 1 response by imhififan

imhififan's avatar
imhififan
2,123 posts
 

When I touch the metal top of the case in addition to the knobs, the noise will subside.

This sounds like the controls are not properly grounded and the case may not be either.

atmasphere +1

Probably the volume and tone control potentiometers bodies are not properly grounded.

If you have a multimeter, check continuity of the power cord ground pin to preamp case, also check volume and tone knobs to chassis continuity.

 

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