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

P-up replacemnt job Now Ground problem

Discussion in 'Pickups & Electronics [BG]' started by Coutts_is_god, Jan 20, 2006.


  1. Coutts_is_god

    Coutts_is_god Guest

    Dec 29, 2003
    Windsor, Ont, Canada
    I replaced the Pick ups in my squier P-bass with Duncan Hot's. I replaced every knob and switch but now it buzzes. Then when I touch it, it stops. The funny thing is. It did this even before I replaced everything.

    I believe it is a grounding problem. Could it be a shielding problem? I Didn't add any extra shieldling to the thing.

    Can anyone help?
    James
     
  2. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    Make sure the problem's in the bass. Just becuase both setups did it does mean it's the bass, indicates more otherwise actually. Cord and location in particular are common sources. Play the bass someplace else with another cord through another amp in prefably a newer building that would be up to electrical code.

    In the bass itself I'd check the bridge ground with a meter first. If there's no continuity between the bridge and jack, there's no ground. The Jack itself is also a common problem - occassionaly defective but usually miswired.

    If the amp has a polarity switch, flip it over. If there's a bunch of electronic garbage in the room, unplug it or try a different circuit away from interference.
     
  3. Connect all the grounds to one and only one point.
     
  4. Coutts_is_god

    Coutts_is_god Guest

    Dec 29, 2003
    Windsor, Ont, Canada
    What am I looking for when I use the meter? Where do I touch the two needle things?

    Could I just cover the entire inside of my bass with copper shielding? Leave no area unshielded?

    Should I screw a screw in the inside body? Attaching all the ground wire directly to the body. That would get rid of all the ground wire I used and have it all leading to one area.

    Thanks for the help
     
  5. Coutts_is_god

    Coutts_is_god Guest

    Dec 29, 2003
    Windsor, Ont, Canada
    Would common house hold Tin Foil work as a good shielding?
    I would use wood glue. Spreading it thinly along the foil, so I wouldn't have huge gobs.
     
  6. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    Just stick the meter on RX1K (or equivalent on yours), stick the leads together to make sure it's working and see what you're getting, then put one lead to the bridge and one to the face (where you plug in outside the bass) of the input jack. You could touch it to the ground terminal of the jack but why bother to take the bay cover off when you don't need to.

    Shielding is for external interference not internal defects and is not going to resolve a ground problem unless by some accidental fluke you correct the ground problem in the process of shielding. Shielding is also ideal for electrical shorts and has other downsides. P pups are humbucking so hum should not be an issue - unless you love cutting bass and cranking trebles.

    Center ground wouldn't make any difference for the same reason. It's the quality of the ground not how it's grounded - it all goes to the same place in the end.

    Been there done that. Tin foil is designed for cooking. The only thing I can imagine worse is to glue it down. Material wise it would shield effectively but it tears easily and doesn't lay flat well. Looks like Sh@# too as is simply bourgeois. Shielding a bass is not a quick fun project so if you're going to take the time to do it, I would do it right to begin with. You could however throw down tin foil as an experiment cuase if that doesn't resolve the problem, throwing down copper probably won't either. In the process you will also see why it's not the permanent fix and unlike putting down copper, you could throw foil down and rip it out in about 15 mintues- probably 5.

    I would defintely make sure you've got the jack wired properly and verify the problem is in the bass before removing anything.

    What do you mean you didn't add any "extra" shielding to the bass, what shielding has it got?
     
  7. Coutts_is_god

    Coutts_is_god Guest

    Dec 29, 2003
    Windsor, Ont, Canada
    It has like 14 cm of tin foil like paper around the inside of the pick gurd where the controls are.

    I crank the bass and the treble mids are low.......
     
  8. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    The pickguard shielding is standard and whatever it is or however it's applied it's considerably more substantial than aluminum foil. You'd never get aluminum foil to adhere like that. Seems somebody said Home Depot has some aluminum adhesive backed foil that would work but aluminum foil will work too, it's just not desireable. You can solder to copper shielding, I don't if you could to that stuff or not.

    The frequency spectrum is interactive and that's exactly what should occur if by bass you mean bass frequencies not bass as in bass guitar. Mixing tone is like mixing colors, if you take a gallon of each of the primary colors; dump them all in one bucket and blend, what you've got is 3 gallons of one ugly useless muddy color. Quality tone comes from knowing how much of each to use and where to apply it.

    For eq'ing try cutting what you don't want instead of cranking what you do want. Tone controls are for tone and volume controls are for volume. Get the tone you want then set the volume.
     
  9. Coutts_is_god

    Coutts_is_god Guest

    Dec 29, 2003
    Windsor, Ont, Canada
    So pretty much just buy the copper shielding from home depot and lower the treble when using the P-bass.
     
  10. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    to my knowledge Home Depot have copper shielding. Somebody posted they used an aluminum adhesive-backed shielding from there - probably used in duct work. Again, to the degree the source of the noise is internal, shielding's not going to help.

    Decreasing treble will decrease hum but that's of minimal use if you want that treble in the tone. What I was saying was to decrease bass instead of increasing treble to get to a like tone. That will allow use to use less treble. You can also increase mids and cut treble to get a like tone. Cut any tweeters off. It's not going to be exactly the same but it should be passable at the least. Different variables (tune, preamp, speakers, etc.) will put limits on what you can do with what you've got. You just have to play around with the eq'ing to see what works.

    I would wire the pup straight to the jack just to see if it does the same without the harness. Sometimes you can swap the lead connections and it will shut a pup up.

    Really sounds like a grounding issue. That you replaced the controls increases the likihood of that. What's the switch for?
     
  11. Coutts_is_god

    Coutts_is_god Guest

    Dec 29, 2003
    Windsor, Ont, Canada
    I'm not sure what you mean by switch.

    I followed the diagram that came with pick ups to a tee. Is this normal for this to happen?
     
  12. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    FWIW:

    "I replaced every knob and switch but now it buzzes."

    That's an excerpt from your first post.

    That everything looks fine really doesn't matter at this point. For starters there are things that can't been seen. And there have been countless posts where it looked fine only to find out they'd wired it wrong.

    You've got a problem you want to resolve and you're going to have to DO something different to figure out what it is since the status quo isn't cutting it.

    You can do it yourself, take it to somebody, or just live with it. That's up to you.