1. Join Now

    AVForums.com uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

possible ground loop, any advice?

Discussion in 'AV Receivers & Amplifiers' started by chrisgeary, Dec 4, 2003.

  1. chrisgeary

    chrisgeary
    Well-known Member

    Joined:
    Jul 23, 2003
    Messages:
    2,505
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Newbury
    Ratings:
    +175
    all,

    i have just gone outboard for my amplification. ive got a meridian 505 sat at the front of my room on the same power supply as the sub. at the back of my room is the source kit, supplied from a different socket. the line level interconnect is home made.

    this is what i know:

    - the system has no ground loop normally.
    - introduce the 505 fed from my 3803's front outputs and there is a buzz.
    - turn the 3803 down to infinity and the buzz nearly but not quite disappears.
    - if i earth the interconnect to the mains earth at the front of the room, the buzz nearly disappears.
    - if i switch sources on the 3803, the buzz disappears whilst it switches and then reappears on every source.
    - i've disconnected the mains for each source, no change
    - i've disconnected the FM aerial, no change
    - i know the 505 is sound as it is silent when nothing is connected to its input.
    - i've run an extension lead so the 505 is fed from the same place as the av kit
    - im using unbalanced inputs only.
    - i measured the offset between neutral and live:
    .097v at the front of the room
    .115v at the back

    any ideas what i'm missing?

    cheers

    Chris
     
  2. chrisgeary

    chrisgeary
    Well-known Member

    Joined:
    Jul 23, 2003
    Messages:
    2,505
    Products Owned:
    0
    Products Wanted:
    0
    Trophy Points:
    86
    Location:
    Newbury
    Ratings:
    +175
    solved it, well actually a friend of mine did!

    the Denon 3803 isn't grounded to mains earth. when we removed mains earth from the 505, the buzz nearly disappeared, but not quite. we put that back and then earthed the 3803 via the phono ground point to mains earth - the buzzing disappeared.
     

Share This Page

Loading...