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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
curiousjim's avatar
curiousjim
4,776 posts
 

I’d never had a problem with Ground Loop until my wife turned on an infrared space heater in the basement.  I had no idea what was happening and it drove me nuts until I figured it out.  What’s funny is we switched to a regular space heater and haven’t had any issues since.

georgeab
95 posts
 

I have had a similar issue. Finally resolved with isolation transformer. You may consider using a cheezy inexpensive audio xformer ($12 on Amazon) for troubleshooting before purchasing something like the iso-max that uses Jenson transformers.

oldrocker52's avatar
oldrocker52 OP
15 posts
 

Thanks everyone for the input. I have a friend that used to be licensed but now retired to give it a go over. I'll post this Sunday if that device worked and if my friend has time to take a look at it.

invalid
1,203 posts
 

@erik_squires 

your luxman is up to NEC standards I assure you, it is internally grounded. You don't have to have an equipment ground to be NEC approved.

erik_squires
16,146 posts
 

@invalid AFAIK, the equipment ground is not an NEC thing but a UL thing.

AFAIK, you do not have to ground a metal chassis IF the power supply is double shielded from the chassis. The Luxman is not double shielded.

What does internally grounded even mean?

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