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re: still trying to track down a hum...
24.17.203.116 |
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Posted on September 15, 2012 at 01:41:53 | ||
Posts: 454
Joined: March 13, 2002 |
It's been a few months since this problem arose with my Citation V re-build, I tried many of the suggestions from that first post, but still unable to cure the problem... I am getting a hum from both channels, if I short the inputs it goes away... if I have one input connected it's fine, if I plug the other channel in, it hums. I have tried several sources, it does this regardless of pre-amp or source. If I plug different sources in each input, for instance I tried two identical CD players, one in each side, no hum, but if I plug into the same source, hum.. I can hook the amp up in mono and the hum doesn't go away, but is significantly, 70% - 80% reduced.. I want to say this is a signal problem, and some sort of ground loop issue, but I'll be damned if I can track it down.. there don't appear to be any grounds in the signal path other than he RCA grounds which I already tried changing, with no effect. All the grounds for the power supply are good. I tried removing them all and then re-connecting them one at a time, there is no change or reduction in the hum.. so I don't think it's power or filter caps, all of which are new.. I have tried several different RCA cables, and different locations for power in other rooms, checked for florescent lights, changed to a 3 prong ground power cord, tried different grounds for the RCA jacks (RCA's are new) the hum is unchanged.. I have not changed the co-ax wire, but I really doubt that's the issue.. any ideas or new investigative paths?- any suggestions welcome thanks! |