Ground Loop Hum

Discussion in 'Speakers & Subwoofers' started by WilliamJay, Nov 9, 2003.

  1. WilliamJay

    WilliamJay Stunt Coordinator

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    I am demoing a Jolida JD 502B integrated amp to power my main speakers. Is sounds great. However, when connecting the Jolida to the pre-outs of my Denon 2802 so that it could be used as part of my HT setup, I noticed a loud hum coming from the speakers and nothing else, no dialog was coming through. The hum disappeared when I disconnected the coax cables from the cable box. What can I do to eliminate this hum?

    Also, when I played a DVD, although I could here dialog coming from the front speakers, all 5 of my speakers were producing much less volume than they should at the indicated volume level on the Denon.

    Any help would be greatly appreciated.

    Thanks,

    Bill
     
  2. John Robert

    John Robert Stunt Coordinator

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    Cable boxes are notorious sources of ground loop problems. Do a search here or at AVSforum for many issues and solutions...
     
  3. Kevin. W

    Kevin. W Screenwriter

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    You need a ground loop isolator(Radio Shack) to solve the hum. Also you need to recalibrate your setup with a sound level meter now that you've added an amp. I think it has something to do with Input Impedance/Sensitivity of the amp and the output level of the Denon(someone else may want to jump in hear). Or the fact your using a tube amp at 60w per where as your Denon is 90w per.

    Kevin
     

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