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effects hum problem

Discussion in 'Effects [BG]' started by cicatrice, Feb 24, 2006.


  1. cicatrice

    cicatrice

    Jun 11, 2005
    Sorry for making yet another thread on hum, but I'm not sure whether I have a ground loop problem, or something else, and most everything I've tried to fix it hasn't worked.

    Here's the deal:

    I'm using a daisy chain adapter (Visual Sound Onespot-- only has two prongs, no ground) for a sequence of three pedals:

    Bass --> Zoom 708II --> Boss GEB-7 --> Boss ODB-3 --> Amp

    The AC adapter is approved for, and works with, with all of the pedals.

    The hum is present when:

    - The bass is or is not plugged into the chain.
    - Amp and effects chain are plugged into the same wall outlet.
    - Amp and effects chain are plugged into different wall outlets.
    - The order of the pedals on the daisy chain is changed.
    - The order of the pedals in the signal chain is changed.

    The hum is NOT present when:

    - The Zoom pedal is the only device on the daisy chain, and the Boss pedals are running on battery power.
    - The Boss pedals are the only ones on the daisy chain, and the Zoom is running on battery power.

    The Zoom uses 4 AA batteries; the Boss pedals use a 9v each.

    Anyway, I think the Zoom pedal is causing the hum, but I don't know how or how to correct it.

    Any help or suggestions would be really, really appreciated!

    Peace,

    -John
     
  2. seanm

    seanm I'd kill for a Nobel Peace Prize! Supporting Member

    Feb 19, 2004
    Ottawa, Canada
    Sounds like a ground loop to me. Try using a seperate one spot (or other adapter) for the Zoom pedal.
     
  3. pbd

    pbd Commercial User

    Jul 17, 2003
    Metro Detroit
    owner Procables N Sound
    checking the gear a little on line I noticed the Zoom seems to have a center minus for the ac adapter. Check the schemo's for your boss', Zoom and your one spots to be sure that your feeding the correct polarity to your gear.

    Hope it works out.
     
  4. Dash Rantic

    Dash Rantic

    Nov 12, 2005
    Palo Alto, CA
    I don't know what causes hum, but a good gate pedal could be useful to stop it. I've used a Boss NS-2 before, worked really well for getting rid of the hum while you're not playing.

    If you can hear the hum while playing, a gate won't fix that. But if you're just concerned about times that you aren't playing (even a rest in a song), a gate might be good for this situation.

    -Dash