My Impossible hum issue.

I have tried movig the ground wires using one from the turntable to both preamps and just one or the other preamp or no ground at all. I have been using an upgraded interconnect cable (Pangea turntable cables with integrated ground wire) and not the one that came with the turntable. The turntable is a Technics SL-100C (essencially the same as the SL-1500 without the built-in preamp). I can hear a sound if I tap on the on the tonearm...maybe there is something wrong there. My control preamp is a Parasound Halo P 6 and the phono preamp is a Parasound JC3 JR. I realize I have budget gear, but I don't think that's the problem. I appreciate the input. Thank you.

Is this a new problem, or did this setup previously work ok? What phono cartridge are you using? Can you hear the hum when the music is playing?

Also, you haven’t ruled out an internal break in an IC wire, most likely the phono cable but could be elsewhere, that interrupts grounding. To check that just insert some cheap alternative ICs in place of what you’re now using. For one, try the Sony supplied phono

cable. Like Russ suggested also check cartridge pins, internal tonearm wires, and joint between headshell and arm wand. Is it tight?

I dug-out the cheap cables that came with the turntable--including the power cable. Replaced the Pangea Audio phono cable and power cable. NO MORE HUM!!

I can't beleive it. Even at the highest gain setting--no hum. The phono cartridge is a Zu/DL-103 Mk.II. Everything sounds great, now.  Thank you to all who weighed-in on my problem.

So now figure out the difference between the cables that work and the ones that don't.  Probably in the way they are grounded.  And then you can order upgraded cables that don't hum.

Audio envy has offered cables with versatile grounding systems and I think they are pretty good at customer support.   Other cable makers are too.

Congrats.

Jerry