Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

grounding issue

Discussion in 'Luthier's Corner' started by chachainsaw, May 18, 2005.


  1. chachainsaw

    chachainsaw

    May 18, 2005
    i just got this P Bass as payment for building a website, it needs some work. it didnt have a jack when i got it, i put one in last night and it works, but theres a pretty loud hum whenever i touch the bridge. i havent put strings on it yet, but i can only imagine that it will hum when i touch the strings too.

    the ground wire is mounted under the bridge and is making a good connection, should i try grounding it somewhere else?

    any help would be much appreciated.. thanks.
     
  2. andvari7

    andvari7

    Aug 28, 2004
    Ennui
    I don't mean to make you sound like you don't know what you're doing, but did you connect the other end of the ground wire to the jack? If you need P-Bass wiring plans, Fender has them, and they're free. A bit difficult to read at first, but quite free.

    Other than that, I really can't think of any reason why there should be a hum.
     
  3. chachainsaw

    chachainsaw

    May 18, 2005
    the ground wire is connected to the tone pot.
     
  4. I dont really know to much about this but when I had a little hum I re sheilded my control cavity and that helped
     
  5. chachainsaw

    chachainsaw

    May 18, 2005
    actually it was connected to the volume pot. but i just tried wiring it to the jack and it works now.

    and i really dont know what im doing, so no offense taken.
     
  6. ArtisFallen

    ArtisFallen

    Jul 21, 2004
    you're getting a hum when you touch the bridge? or are you getting a hum when you stop touching the bridge?

    if you're getting a hum when you stop touching the bridge, it's normal, but if it's bad, shield your cavity.

    if you're getting a hum when you touch you bridge, then it's probably wired wrong, and needs to be re-done.

    here's the schematic if you happen to need it
    http://www.stewmac.com/freeinfo/I-0139.html
     
  7. chachainsaw

    chachainsaw

    May 18, 2005
    yeah, i was getting a hum when i touched the bridge. i re-wired the ground to the jack. its all good now. thanks anyways.
     
  8. jamiedunce

    jamiedunce

    Jan 21, 2005
    Ive got a similar problem. On my spector Pro q-4, Im getting a hum when I touch the pickups, but its grounded properly. Its quite a loud hum too and pretty annoying. Any ideas?
     
  9. If you touch a pickup pole pieces you'll get a hum, this is normal, because you're basically grounding the hot when you do that.
     
  10. jamiedunce

    jamiedunce

    Jan 21, 2005
    They are EMG-HZ passive humbuckers though. Ok, so I took the bridge off and made sure it was grounded properly. Then put it back on, and now it hums when I touch the strings and the pickups!