Buzz Hum Problem

[tony3d]

Hi, I was wondering if you could give me some input to a slight problem I have been having? The other day I still noticed the very slightest kinda hum buzz going on in both of my channels. It can only be heard at all if the amp gains are past half way up. If you were not listening for it most people wouldn't hear it. I noticed it after playing my Nakamichi cd player, and switching over to my Harman Kardon CDR-26. The Nakamichi is dead silent. All I have to do is turn on the H/K and I get the noise! I don't even half to be on the H/K's input, just turn it on. I'm sure this is some kind of ground loop, but I don't want to put any signal degrading isolation transformer on the H/K outputs. Any suggestion? I was thinking of grounding the Chassis directly to the my Crown IC-150's chassis. The connecting cables between the H/K and Ic-150 are quite old, but then again so are the one's between the Nakamichi and the IC-150. This is the only component giving my a noise issue. Everything else is dead quite! I tried moving the H/K's power cord to a different outlet with no improvement. My Ic-150 is connected to a Crown XTI-2000 power amp.

 

[bowtie427ss]

Try running an extension cord from a KNOWN DIFFERENT circuit to the HK.

My guess is that the IC-150 is common chassis grounded, but gets along with the rest of your equipment. Not really sure why your HK doesn't want to play nice with the rest of the family, the solution may ultimately be in a power conditioner/isolator.

EDIT: i should add that ground loops can be tricky things to track down, especially small leaky ones like what you're describing. Even tho it's being evidenced by the HK, the HK may not be the root of the problem. Does the IC-150 have a 3 wire grounded power cord/plug? If so i'd try lifting that ground, of course other's will tell you not to, but since your equipment is known to all be properly functioning, and your lines are all fused there will be no harm in lifting the ground for the duration it will take to see if that eliminates the loop.

Here on my home turf where i run any of my larger equipment, i have pairs of outlets on individual circuits on opposite legs if the incoming AC mains, some of my ground loop issues are quickly and easily solved by powering the culprit from a different circuit than the rest of the system.

FWIW, i've not been happy or had good luck with anything newer bearing the Harman name and i now avoid it all like the plague.