my geddy bass still hums after humbucker installation

Discussion in 'Pickups & Electronics [BG]' started by Jonki, Dec 17, 2005.

  1. Jonki

    Jonki I will not slap my Bee!

    Oct 14, 2003
    Arendal, Norway

    my geddy still hums after i installed a pair of DiMarzio Model J.
    i have connected the pickups in series and added coppershield in pot cavity, the other wires and couplings is factory standard.

    what shall i do?
  2. Nino Valenti

    Nino Valenti Supporting Member Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
    Did you shield the Pickup cavities? if so, are all the cavities grounded to each other?
  3. Jonki

    Jonki I will not slap my Bee!

    Oct 14, 2003
    Arendal, Norway
    nope, i dindt have enough coppertape to do that :(
  4. DemoEtc


    Aug 18, 2004
    Have you also tried different cables or maybe a different amp? Could be a cable with a broken shield. Also, sometimes, certain homes or houses have a problem with wiring (in the walls or under the floor), or there might be something giving off a magnetic signal nearby, like a transformer or even the computer you might sit in front of. Sometimes moving things around or plugging the amp into a different wall socket will help.
  5. Might I also add that Model J's and UJ's are quite noisy for being humbuckers, and no matter how much shielding and proper grounding you do, you'll still get slight hum when you aren't touching any metal part. This has been my experience with both types, and I know a few other people have experienced this also.

    The plus side is these pickups sound so damn good for the money that noone really cares.
  6. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    I have the Sadowskys (UJ variants) in my Jazz and they are dead quiet, no matter whether I'm touching metal or not. It's all in the shielding.
  7. Dan1099

    Dan1099 Dumbing My Process Down

    Aug 7, 2004
    I've got a set of Aero single coils in my Marcus Miller, and it's dead quiet unless you favor one pickup or the other. It's all in a thorough shielding job.
  8. eots


    Dec 18, 2004
    Morris, IL.
    less hum usually comes from using the pups in parallel, shielding or not.
  9. are you sure the grounding on your amp is good enough... it might be the elctronics in you house.. for instance my bass doesn't hum when I'm in music school but it does in my garage..
  10. +1 my single-soapbar bass has zero hum in parallel, and a tiny bit of hum in series...and the shielding is good...however, I am next attacking the pickup cavity with some foil.

    Thanks for the additional information, folks... :)
  11. tadawson


    Aug 24, 2005
    Lewisville, TX
    Teach it the words? (Sorry, couldn't resist . . . ) ;) ;) ;) ;)

    - Tim
  12. luknfur


    Jan 14, 2004

    Given the assumption you've grounded the bridge and that you shielded the control bay (therefore had to remove the electronics), I'd run a meter to check continuity from the bridge to the jack to make sure the bridge ground is making contact. I'd also use the meter to check pot to pot for possible faulty grounds whether their factory or not. Also any hot lug (or protruding lug lead) that comes in contact with the shielding (floor or wall) is automatically grounded and I'd check for that while I was at it. Usually I tape a piece of electrical tape to the floor beneath each set of lugs along the wall where any hot lug is close. Any mini-switch is a prime candidate for problems due to tight soldering points. Jacks are always suspect till ruled out.

    I would also definetly rule out the location, amp, cord, all esle in the signal chain.

    If you crank trebles or have a tweeter active you're much more likely to get racket.

    Touching the strings should reduce any hum, otherwise it's an indication of possible poor ground. You might find you only get hum when facing the amp in certain directions also.

    But all that comes to mind.