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 4 responses by mofojo

mofojo OP
2,173 posts
 

No it’s at least 2 ft away from the closest component. 

mofojo OP
2,173 posts
 

I can have just one of my grounded components plugged into the dedicated line with the amp. Any of them. When I hook it up via rca to the amp the hum is pretty loud. Float the ground in that component and the hum is gone. 

mofojo OP
2,173 posts
 

@jea48 

“Are you using the OEM power cord that came with the Krell Amp?

Is there a ground loop hum with only the preamp connected to the Krell amp? (Nothing connected to any of the inputs on the preamp. No other type of ground wire(s) connected to the preamp either.

If yes there is hum with only the preamp connected to the amp, (nothing connected to any preamp inputs. No external ground wires connected to the preamp... For a test install a ground cheater on the power cord of the Krell amp only. Hum should be gone... Yes?

 

Just curious are the shorting jumpers, pins, installed on the XLR inputs?”

 

Not using the power cord that came with the Krell. It did not come with it unfortunately. Using an older large gage probably 1 grand cable from its time. Can’t recall the brand offhand and it’s worked flawlessly with other amps. 
 

shorting pins were not connected, again I did not get them. I did buy some XLR cables to go from dac to preamp and from preamp to amp and same thing. 
 

Preamp with nothing connected to it causes same issue. 
 

thanks

mofojo OP
2,173 posts
 

I REALLY appreciate the ideas! You guys are kinda talking over my head right now. Not sure what was said in the last few posts that I can physically apply or check for a resolution. I need something like :

 

take your meter, put it here..

look for this…. 

if this is this then it’s probably this… lol

 

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