Strange thing happened when I got my new turntable (Marantz TT15S1 Reference Series).
When I cranked up the volume to near reference (since the phono input is so much quieter then the hdmi inputs for some reason), the turntable would HUM at 0db when I touched the carbon arm.
If I touched the metal nothing would happen.
So obviously I thought a grounding issue with the marantz, so I double checked everything, pulled out the multi meter, verified the ground paths, everything was fine. Hum still was present when I touched the carbon arm (only noticeable from -15db getting louder as approaching 0db).
I thought obviously a defective unit, so off I went to the dealer. We checked their unit, and it was not exhibiting the same noise situation (plugged into a Marantz AVR).
Here is where things get strange. I asked to hook my turntable up to their unit, and sure enough at 0db, no noise on their setup.
We tried another AVR, same result no noise.
So when I got home , I hooked everything BACK up , verified continuity between the ground paths. Sure enough, it HUMS at 0db when touching the carbon arm.
Anyone have an idea? Just an interior phono stage?
Does anyone have a turntable where they could try this out with their AVR-4520ci, and see their results?