2. amps-preamps
  3. 184310-3592

Krell KSA 200s ground hum

I picked up this amp a week ago and I REALLY like it. When I first plugged it in with nothing attached except speakers it was silent. Like small hiss from an inch away but one of the more silent pieces I have had. As soon as I hooked up an rca from my preamp there it was. Loud ground hum. So right now I have floated the ground with cheater plugs on everything in the chain. Silence all is good with the cheater plugs and the system sounds great. If I take the cheater plug off of any of the 5 pieces in the chain it’s back! All same outlet and dedicated 10 gage line. I mean I’m “ok” with the cheater plugs if need be but…….. any ideas? 

mofojo

Showing 1 response by ieales

ieales's avatar
ieales
1,201 posts
 

Verify that XLR pin 1 is connected to the line earth. It may have a low value resistance like 10Ω if there is a loop break.

In recording studios we used twin screen, connected RCA pin to +ve, and -ve & screen to the shell at the source. At the amp XLR, +ve to +ve and -ev ONLY to -ev. Screen unconnected at amp.

If that does not work, there is an issue with the source earth.

If you are going to use cheaters plugs, ground the amp and lift everything else.

 

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