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Noise From my Bart Preamp

Discussion in 'Basses [BG]' started by kp_funk, Feb 9, 2005.

  1. kp_funk


    Jun 9, 2003
    Hi All,

    I installed Bart pickups, and a Bart Preamp (NTMB) in my bass. I however am getting a hum when I turn my bass all the way up, and gets worse of course when I boost the treble. My first question is whether this is normal for bart preamps or do I have a ground issue. If I do, how can I get rid of it.
    Second question. What is the easiest way to ground the preamp to the the bridge? Do I have to cut through the wood? Is there a neater way??

    Do I have to ground it to the bridge or can I ground it another way? Any electrician experts out there who can give me some advice, please let me know.
  2. I guess the first question would be if you installed hum-canceling pickups (Humbuckers, dual-coil) or not... If not, then the preamp is just going to amplify the noise picked up from the pickups... There has to be a post on here somewhere about the importance of shielding and all that stuff... I'm a newbie to this...
    Grounding the preamp to the bridge?? I believe that for best results, the bridge should be grounded to your output jack and that the preamp should be grounded to the output jack as well... If there isn't a wire there already, it involves carefully drilling a hole from underneath the bridge to your electronics cavity.
    Hope this helps... -Willy
  3. kp_funk


    Jun 9, 2003
    I do have hum-cancelling pick-ups. I guess I'll have to drill that hole to ground at the bridge. I hope it works.
  4. ShamrayBass

    ShamrayBass The Bass Custom Shop

    Dec 29, 2004
    Moscow. RUSSIA
    I would say that probably your bass ALREADY HAS a string ground (unless it came stock with EMG active pups, it almost CERTAINLY does!)

    of course, its possible it got broken or otherwise disconnected along the way :)

    Borrow a "multimeter" and check for continuity between the bridge and 'output jack ground' BEFORE you start cutting wood!
  5. JOME77

    JOME77 Supporting Member

    Aug 18, 2002
    I have Bart pre's in 3 of my basses and they are extremely quite. If you don't have a bridge ground run to the ground for the electronics that would certainly be a problem. You also need to make sure that all pots, switches and jacks are grounded together. The simplest way to do that is installing a single piece of copper shielding with a self adhesive in the control cavity where all components mount. The only down side to that is if a pot or switch gets loose, you lose your common ground. The best way is to soldier a wire from pot to pot (or sw). If there's not a good place to soldier to on a switch or pot, soldier to a star washer large enough for the device (pot/sw) threaded shaft to mount through. Did you purchase a pre-wired pre or did you do the wiring yourself?
  6. kp_funk


    Jun 9, 2003

    Sorry for taking so long to reply. the pre came prewired. But I think the tech disconnected it when trying to install it.