Hum on amp

Discussion in 'Pickups & Electronics [BG]' started by ScreamSalvation, Dec 27, 2005.

  1. ScreamSalvation


    Dec 27, 2005
    I just rebuilt my fender P-Bass a little while back. Put a new paint job on it... new bridge.. and new seymor duncan quarter pounder pu.. I haven't had a chance to play in the last 2 months so i put it together and never really played. I picked it up today and everything works correctly but i have a little hum till i touch my strings or bridge.. Is there a grounding issue with something? I didn't do a wire from the low side to the bridge as I have seen other do.. do I need to do that?
  2. ScreamSalvation


    Dec 27, 2005
    Excuse me... it is when i touch the cable connectors when the hum stops. Cable is brand new
  3. luknfur


    Jan 14, 2004

    by cable I assume you mean the guitar cord. May be the cord, may be the jack, may be lack of a bridge ground among other things.

    The first thing to do is isolate the problem and determine whether it's in the instrument or not. Just because the instrument was recently worked on doesn't mean the problem is necessarily there - although it probably is, you just don't want to assume that and go tearing into it without verifying it really is the source.
  4. PhilMan99


    Jul 18, 2003
    US, Maryland
    I vaguely remember reading in the last couple of days that hum is more noticeable with bigger magnets. The quarter-pounder has a big magnet.

    You *may* find that you need to add better shielding in the cavity of your instrument (where the pots are), assuming you're getting mild hum. I also recall reading recently that Fender's shielding is typically poor, but this is more in the context of a Jazz.

    Substantial hum would probably indicate a bad ground-wire someplace.
  5. georgestrings

    georgestrings Banned

    Nov 5, 2005

    Sounds like a faulty bridge ground to me - take a resistance reading between the bridge and the jack... I recently sheilded both my P basses, though - and it made a WORLD of difference - it wasn't that hard, and didn't cost me anything... Make sure you have a good bridge ground, and if you can, sheild the inner cavity - and you should be good to go...

    - georgestrings