60 cycle hum issues

Discussion in 'Home Theater Projects' started by Ray_C, Nov 3, 2004.

  1. Ray_C

    Ray_C Stunt Coordinator

    Joined:
    Jan 6, 2004
    Messages:
    106
    Likes Received:
    0
    I'm getting some 60-cycle hum with my Denon AVR2805, but I don't get it when I run my Sony TA-P9000ES through the same amp with either the SACD (same Denon 2200 player as DVD movies through 2805) or CD player, but I do get it when I run my 2805 with either TV or DVD movies....so it seems to be the 2805. The hum gets kinda buzzy when the TV's on, but still remains when the TV is off. I'm hoping one of these:

    http://www.action-electronics.com/phciso.htm#Isolation

    will help. I'm planning on plugging it in between the wall socket and the Monster power strip that I have all my AV equipment plugged into. Any thoughts/experiences in general?







    Edit *
    Reply *
    Quote *
    Quick Reply *
     
  2. Wayne A. Pflughaupt

    Joined:
    Aug 5, 1999
    Messages:
    6,100
    Likes Received:
    33
    Location:
    Katy, TX
    Real Name:
    Wayne
    That gizmo looks pretty cool, but it will only work if the equipment you’re plugging into it has grounded plugs.

    In most home theater situations the source of the ground loop is the cable TV feed, or an improperly grounded satellite feed. Do a search on this Forum and on our Speakers and Subwoofers and you’ll find info on some remedies.

    Regards,
    Wayne A. Pflughaupt
     
  3. Ray_C

    Ray_C Stunt Coordinator

    Joined:
    Jan 6, 2004
    Messages:
    106
    Likes Received:
    0
    Thanks Wayne. the Denon does not have a grounded plug...which I find strange. The problem is not with the cable, as I removed it and nothing changed. I wasn't experiencing this before I got the Denon. Is there any way to help ground the receiver...like a ground screw or something on the outer chassis that I can wire?
     
  4. Ray_C

    Ray_C Stunt Coordinator

    Joined:
    Jan 6, 2004
    Messages:
    106
    Likes Received:
    0
    Some of this might have to do with the myriad of interconnect cables I've recently added since getting an Outlaw ICBM. Heres an Idea:

    SACD to TA-P9000ES preamp via 5.1 analog, TA-P9000ES 5.1 pre out to Outlaw ICBM 5.1 in, Outlaw ICBM 5.1 out to 5-ch power amp and sub.

    Cd player is connected via analog L/R to the L/R in of 5.1 'channel 2' of the TA-P9000ES, and the rest of the route is the same as above.

    DVD to Denon AVR 2805 via Digital Coax, 2805 5.1 preamp out to 5.1 'bypass channel' of TA-P9000ES, then same route as above.

    So right there, I have 22 different rca audio interconnects snaking (albeit rather neatly) behind a stack of six components....not including the the TV and VCR connections. Even though I did what I could to keep the power cables away from all these interconnects...did I basically create a virtual radar net with all those interconnects...thus contributing to the hum/buzz?

    EDIT: Found it!! Although I don't know what to do about it.....it's the S-Video cable going from the monitor out of the receiver to the television. Same thing with a composite video...unplug the cable fro the TV, no buzz and very low hum. PLug it back in, it's all back. But I'm getting the same thing if I plug a video cable straight from the cable box...even if I UNPLUG the cable box...and even when I unplug the TV!! So.....there's some sort of thing going on that the sound system just doesn't want to have anything to do with the TV except through compnent through the DVD player. I'm stumped.

    Is there anything out there that sends video signals via remote...like a walkie-talkie?
     
  5. Dean_S

    Dean_S Second Unit

    Joined:
    Feb 4, 2004
    Messages:
    261
    Likes Received:
    0
    Try this. Plug everything back in the way you had it, turn on the TV and cable box and then unplug the cable input from the cable box. It is common for cable to cause this type of problem and two 75-300ohm converters (wired with the 300ohm side together inline before the cable box) can solve this problem.
     
  6. Ray_C

    Ray_C Stunt Coordinator

    Joined:
    Jan 6, 2004
    Messages:
    106
    Likes Received:
    0
    Thanks for the response, Dean. Yeah, I tried that a couple of times and it wasn't the culprit. Clearly there's something up with how the sounds system feels about the TV itself. I did away with the composite/s-video monitor approach and instead used the component monitor out of the Denon 2805 (routing the DVD player's compnent out through the receiver), and it improved things a bit, and the prog scan picture out of the DVD player looks fine. There is still some slight hum with a tiny bit of sizzle, but not nearly as much as before with the buzzing. It's only really noticeable when very close to the speaker, but not if you're about 5 feet out, unless everything else, including the room, is completely silent. Not really bothering me right now, but I'll have to do some further investigation into it.
     
  7. ScottLR

    ScottLR Stunt Coordinator

    Joined:
    Nov 28, 2003
    Messages:
    68
    Likes Received:
    0
    60 cycle hum sucks. I recently moved, and on my audio-only system has it. I have everything plugged into a voltage regulator/conditioner (I've tried 2 brands) and still hum. I bought a Monster HTS-3600 very cheap on Ebay (not here yet), so I'll see if that works. I doubt it will.
     

Share This Page