What's all the **BUZZ** about?

Discussion in 'AV Receivers' started by MarkMac, Feb 5, 2005.

  1. MarkMac

    MarkMac Stunt Coordinator

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    OK, I need help. I've read so many posts about ground loops, isolation transformers, and the like, I'm ready to give up this hobby, and try out painting...I bet there's no buzz when you're sitting next to pond painting a landscape (unless of course you've got a bumblebee dancing around your ear)...but I digress...

    Here's my situation. I've got the TV, DVD, VCR, DirecTV, PS2, Denon 3803 (as pre/pro), and Parasound 1205A running through a Panamax 5300. I have a buzz, yes a buzz--not a hiss, not a hum--in all 5 of my Klipsch speakers. I only have this buzz if the amp is plugged in--it doesn't even need to be on. I tried unplugging each component individually, and the only thing that eliminated the buzz was unplugging the amp. It was really easy to isolate since everything is plugged into the Panamax.

    If I run the speaker wire through the Denon using it's internal amps, and leave the Parasound off and unplugged, no buzz. As soon as I plug the amp in...buzz. I eveb tried the Parasound in a different outlet, and I still get the buzz.

    I'm not sure what do to now. I'd appreciate any suggestions you've got, since, to be honest, I suck at painting.
     
  2. ChuckSolo

    ChuckSolo Screenwriter

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    Maybe there is some internal damage in the Panamax. Have you tried a different amp? You could always pick one up and if the buzz persists with a different amp, then you would know it is not the amp itself but some external issue, power, wiring, etc. However, if it's not the external issue, and the amp itself.....a wise saying goes "If thine amp offend thee......"; you get the idea.
     
  3. Mark C.

    Mark C. Supporting Actor

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    The prime suspect is your satellite connection. It seems that every other install is not properly grounded. Disconnect the satellite from your system and maybe that buzz goes away. If it does, you need a ground isolator (or something like that. Someone help me here). I believe Radio Shack sells them.
     
  4. MarkMac

    MarkMac Stunt Coordinator

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    Swapping out the amp is a good suggestion. I may try that out in the next week or so if I can't get anything else to work.

    Regarding the satellite, I realize that I tried unplugging my Hughes box when I was trying to isolate the problem, but I never unscrewed the input coax (from the dish) out of the back of the Panamax. I'll try that out to see what happens.
     
  5. MarkMac

    MarkMac Stunt Coordinator

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    No luck. I removed the input directv coax and phone line, and the buzz is still there.

    One other thing to note, in case it means anything, is that the volume of the buzz doesn't seem to change regardless of how high I turn up the volume on the 3803; however, if I turn the volume down all the way so it indicates '---' on the receiver the buzz disappears. As soon as I give one click up to '-80db' the buzz starts and stays there all the way up the range of volume settings. The weird thing is that this is the case regardless of whether the amp is turned on or not.
     
  6. ChrisHeflen

    ChrisHeflen Supporting Actor

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    Mark, try putting a cheater plug on the amp power cord.
    While not the best solution, it is a common one. You are dealing with more power with the Parasound. I doubt you have a bad amp. This is very common
    Try a search here on ground loop hum.
     
  7. MarkMac

    MarkMac Stunt Coordinator

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    Sure enough. Using the cheater plug eliminates the buzz. (Thanks for the suggestion, Chris.)

    My guess, though, is that this is not a recommened approach to solve my problem (there's got to be something fundamentally wrong with this [​IMG]). I'll use it for the time being, but I'm going to try to find a "better" solution to eliminate the buzz.
     
  8. ChristopherDAC

    ChristopherDAC Producer

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    I had a similar symptom with my reciever and it turned out to be an unusual ground loop. I had my TV antenna connected to my reciever for FM reception and to a TV in another room for TV reception, and with the two of them in parallel there was a ground loop because the antenna cable was ungrounded -- the wire from the grounding block was attached to the metal of the electrical service box, but testing with an ohmmeter showed that the box was utterly nonconductive! I disconnected the reciever, which works but is suboptimal; the fix I expect is going to be in the household electrical system, which is totally messed up [the place has been rewired at least 3 times, and no 2 outlets in the same room are on the same circuit]. I am hesitant to reconnect both components with a proper ground before fixing the electrical wiring, for fear of drawing too much current through the coax shield, but I'm going to ground it with a copper-plated steel rod one of these days soon with only the TV hooked up. If that doesn't work I'll need to check the components for damage.
     

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