Ground Loop?


I seem to have a ground issue with my phono preamp a Parasound JC3 Jr that just started about 3 months ago. I've tried very thing. A different Preamp (Moon 350p) replaced an Emotiva XMC-1 Different TT but still has the issue whether it's connected or not. I have 2 dedicated 20 Amp lines direct to fuse box and plugged them directly into the sockets bypassing my conditioner Audiance V8. It's a tapping sound with static but when I touch the loading pot in back it stops chattering but has a low-level hum. I have even sent it directly to Parasound and no issues were found. Going nuts!

128x128oldrocker52

Thanks, I'll give that a try in the AM 9 930 I'll give that a try in the AM tomorrow I got to get some sleep I was up with it all night trying to fix this till around 430 am EST. and iy's 1030 now.

Since you mentioned two dedicated circuits, are you using isolated ground receptacles? If so, check the ground wires. Remember, an isolated ground requires an insulated ground wire. You should not use Romex. The ground wire is not insulated. I’m not an electrician but when I installed a new receptacle for my system. Based on my readings, an isolated ground has different grounding specs. In my case, I could not use an audio grade receptacle like PS Audio or any other brand that required an insulated ground wire for an isolated ground. I ended up using a Hubbell 8300 hospital grade receptacle. Hope this helps.

I tried with only the 2 pieces hooked up, nothing else just the Moon 350P preamp and the JC3 Jr phono preamp plugged directly into the dedicated 20 A line. Using 4 different pair of balanced or unbalanced connectors makes no difference. I hated doing this with full intention of returning it, but I ordered a less expensive MM/MC preamp, and it does the same thing too. It's like I'm cursed on vinyl playback.

I have 2 pr. of Cryo-treated watt gate receptacles wired direct to fuse box. It never had this problem before it just kind of creeped in slowly and it can be heard in segways and quiet portions of the music. 

Do your wattgate receptacles have an isolated ground? If so, check the specs. Call their tech support. Most, if not all, isolated ground receptacles will require an insulated ground wire. If this is the case and you are using standard Romex, your ground is compromised.