2. amps-preamps
  3. 1171018677

Buzz Hum Problem

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.
tony3d
chadnliz
3,736 posts
 
Cheater is one of those old jacks we all have used to go from a three prong plug to a two prong plug. It will "lift"
the ground thus eliminating what is called "ground loop hums"....it is common in this hobby.
hartwerger
105 posts
 
I have the same ground loop problem myself eminating from my preamp. I tried a cheater plug which does eliminate the hum, but the sonics suffer terribly. Are there any audiophile quality cheater plugs or alternatives to using a cheater plug? I'd rather have the hum than use the hardware store cheater plug I've used.
cytocycle
1,043 posts
 
PS audio use to make a humbuster which they incorporated into a new product that takes the DC on the ground and grounds it.. didn't help in my system.... but the real problem is typically a COAX cable connection from your video system causing the ground connection problem.. there are a couple of products that break this ground. Disconnect your cable from your stereo system and see if that eliminates your problem.

Mondial Magic will fix this problem, or you can jerry rig it with a 300ohm to 75 to 300ohm conversion at radio shack.. (two adapters breaks the ground..)

http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1162931268&read&keyw&zzmagic+ground

another thread related to this...

Plus if you have monoblocks the problem gets more complicated in that you might have to lift a ground also on one of the monoblocks.

Music Reference recommends lifting all the grounds except the highest current when encountering problems.. so leave the amp grounded.. cheater plug on all others.

Mapleshade audio also has a section on their website discussing the problem and solution.

The worst part is after tons or products, I found out that my problem was a monster interconnect where the shielding was not soldiered correctly... removed the RCA cable at my other place and problem solved!!!!
istanbulu
291 posts
 
Cytocycle... your points re COAX cable are right on for my system... very helpful...

the SAT was introducing a lot of junk...

thanks...
More to discover