is static from my body causing crackling???

Discussion in 'Hardware, Setup & Repair [BG]' started by superphat, Oct 27, 2001.

  1. superphat


    Sep 30, 2001
    hi all.
    i have an odd situation here.
    i'm playing a fender geddy lee (japan) jazz bass, through SWR gear, and usually everything's dandy.
    but on occasion i'm getting a weird crackling sound from my tweeter. at first i thought there was a problem with the tweeter, but i don't think that's it, cuz usually it sounds ok.

    here's the interesting part:
    i was trying to figure out exactly what was causing the crackling... sometimes when i pop a string, but sometimes when i just move my fingers about whether i'm actually playing a note or not.

    and then i touched my bridge pickup with my right hand, while still moving my left hand around on the strings and playing some notes.
    hey! no crackling whatsoever.
    if i take my finger off the pickup, then the noise happens again.

    what's the deal?
    something going on here with bad shielding, or a ground problem or something?
    if someone could offer some advice to one who knows nothing about electronics, it would be greatly appreciated.
  2. Sounds like a grounding problem to me, not an uncommon problem with Fender Basses and high power amps. The most common problem is that the ground wire is not making good contact with the bridge plate. You will need to remove the bridge, be sure that the ground wire is clean and that the contact point on the bottom of the bridge is bare metal with out any protecting coating. If that dosen't fix the problem check all of the other ground connections for a cold solder joint.
  3. superphat


    Sep 30, 2001
    hey thanks for the tip!
    but what are the "other ground connections" and what is a "cold solder joint"??
  4. Aaron


    Jun 2, 2001
    Bellingham, WA
    The other ground connection should be to a pot or the jack. Make sure that is soldered well.
  5. superphat


    Sep 30, 2001
    ok, i've done some more troubleshooting,
    and i've narrowed the problem down.
    it's not the typical j-bass hum,
    and the loud crackling only happens with the bridge pickup. and only when i slap!
    so, what does this mean?
    i checked the wiring and nothing seems to be loose, and the shielding in the control cavity seems pretty decent.

    can a pickup go bad?
    or maybe the pot is bad?
    (i guess this should be in the 'pickups' forum now?)

    i guess i'll take it into the repair shop next week,
    but in the meantime, if anyone has any ideas what the problem might be???
  6. Blackbird

    Blackbird Moderator Staff Member Supporting Member

    Mar 18, 2000
    Check your cord. It might have a bad connection.
  7. superphat


    Sep 30, 2001
    another question to aid in my research here...:p
    can bad shielding cause crackling?
    i know it can cause hums and RFI noise,
    but loud intermitten crackling noises?
  8. Cold Solder joint or dry joint is another common name is when the solder doesn't amalgamate with the other metal. It doesn't form a good bond. You can usualy tell this by the solder joint appearing a dull grey (should be shiny), a slight crack in the solder joint. Or sometimes its hard to pick but if you suspect its a bad connection (in this case ground) sometimes its good to resolder it, give it a freshen up with some quality solder. Not the cheap stuff used in factories. lol


  9. superphat


    Sep 30, 2001
    just in case anyone has a similar problem in the future...
    after much troubleshooting (isolating, trying different things, other locations, etc.)
    i found out that my "crackling" sound is a result of my right hand brushing the pickguard (when i'm fingerpicking nothing is touching the pickguard but when i slap, my fingers kinda drag on the pickguard).

    i'm assuming that it's a shielding problem (all the grounds seem to be securely in place).
    i ordered some copper conductive tape, and i'm going to open it up and try to cover every inch of that sucker.

    i'll let you know what happens.

    thanks again for your opinions.