Rapid pulsing/ throbbing noise


Hello, I recently made my move to SC and finished my set up in my new place.
I encountered a rapid pulsing/ throbbing noise in the phono section in my right channel only. This noise is only at very high volume and the only way I can hear it is to turn my volume up most the way (at about 4:00 position) without a record playing. Now I never listen at that level (max about 12:00 - 1:00) but nonetheless, it's still there and never was before. All I did so far was to change the interconnects and ad an additional grounding wire from my pre amp to phono stage. Any clue as to what might be causing this?
markpao

Showing 1 response by lewm

Are you near to anything with a switching power supply? Some circuits can pick up switching noise. Try the simple test of moving your phono stage and/or linestage/amplifier with respect to any other electronics in the room. If it gets worse or better, you at least can know how to minimize or eliminate it, even if the cause is never certain.