Can anyone figure out what is causing this problem?

Discussion in 'Pickups & Electronics [BG]' started by Flatwoundround, Apr 28, 2016.

  1. Flatwoundround


    May 18, 2014
    Precision pickups and when I touch the pole pieces on the pup that is closest to the neck I get a nasty humming noise. I never noticed this problem before I installed copper tape wound strings. I heard that these strings can cause noise because they are not coated and prevent grounding from touching but how does that relate to the problem I have? Even if I don't touch the strings if I touch the pole pieces on the front pup I get the noise? I am guessing this is a grounding issue that can be fixed and the copper tape wound strings are not the cause?

    Just my luck this happens to me after a long long tone search with various strings and these copper tape wounds I finally feel I found the perfect string and then this dang problem surfaces.

    I appreciate any help at all.

  2. Flatwoundround


    May 18, 2014
    I meant to say that I get the problem when I touch the actual magnets on the front pickup of the precision setup (not the pole piece). I also meant to say above that tape wounds are coated with nylon that prevents the string from being grounded when you touch it.

  3. The problem is that your pole pieces are not grounded.
    megafiddle likes this.
  4. Yeah man, this comes up once or twice a month on this forum. Check out the seach box. I've written lengthy explanations on the cause and the various fixes. As line6 said, you can earth the pole pieces from underneath with copper tape. But you can replace the covers with ones that don't have holes, you can swap bobbins and/or reverse the pickup phase so only one bobbin hums and it is out of the way. If you have a vintage fender, there's a chance that earthing the magnets will short the signal from that pickup. This indicates that the coil needs rewinding...
    Last edited: Apr 30, 2016
    megafiddle likes this.
  5. rufus.K


    Oct 18, 2015
    1. Sometimes you can read wire it with opposite polarity a day it won't do it anymore (swap hot and ground).
    2. Put electrical tape over the pole piece
    3. Has nothing to do with your strings.
    megafiddle likes this.
  6. megafiddle


    May 25, 2011
    Correct, the strings are not the cause, but they are the reason you are suddenly now seeing the problem.

    With the old strings, you were being grounded while you were in contact with them. So even though the pickup pole pieces were sensitive, there was no noise present on yourself for the pickups to sense.

    With the new tapewound strings, you are no longer grounded and are now a noise source. And so the pickups are now sensing this noise through the pole pieces, which are in very close proximity to the coil winding.

    As others mentioned above, you can ground the poles, insulate them, or reorient and/or rewire the pickup halves so the most sensitive area is least accessible.

    You might also try coating the pole ends with clear lacquer (nail polish).

    rufus.K likes this.
  7. . Might try a small copper strip spanning the poll Pieces then SOLDER TO THE LOWER SIDE OF THE COPPER FACING
  8. Flatwoundround


    May 18, 2014

    Thanks. My description was off, I get the problem when I touch some of the magnets

    Thanks much to everyone on the feedback.

    It is actually not the pole pieces but the actual magnets on the pickups that is causing the problem. Eight magnets (Precision pups) but only say 2 or 3 make the noise, and the noise goes away when I touch the magnets and at the same time touch either the bridge, output jack, tuning pegs or volume tone knobs. Of course this is because all those things are grounding out the noise and now I know if I had rounds or flats that would ground out the noise too but the tapes do not since the nylon coating.

    Just a few questions:

    1. Is it common to have a louder humming noise when you touch a magnet on a pickup and also not touching a grounded string or something else grounded?

    2. Can I put a piece of electrical tape next to the magnet so that if I inadvertently touch the magnet I will most likely also touch the tape and be grounded with no noise?

    3. Any other ideas on how to fix this problem?

    Ironically now that I feel I understand the problem, it no longer feels like a major problem anymore.

    Bass Players are Awesome!
  9. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism

    1. Not common but it is a regular thing. I have experienced it with one of my P basses

    2. Yes you can.

    3. Aside from proper grounding I use clear nail polish to coat the pickup pieces, this also prevents contact.
  10. Flatwoundround


    May 18, 2014

    Thanks again. Just so I am clear, it is okay to put the clear nail polish on the magnets on the pickups? I heard of people doing this for the pole pieces on pickups but was not sure if it was okay to use on the actual magnets.

    Last week I bought some hair scrungy things for muting the bass strings and this week looks like I will be buying nail polish too. Amazing what we go through for our instruments.
  11. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism

    I think the pole pieces are the magnets but I could be wrong. Just take off your covers and coat the pieces, you need to let a layer dry a little before you apply another layer.

    I bought stacks of scrunchies, never found anything to actually work so I ended up with fretwraps. It was pretty funny for me when I went to get nail polish though. I had to ask one of the girls to help me find it, as well as which was the strongest, but after asking where it was I clearly and loudly explained it wasn't for my nails. I more so blurted it out before I even realized I was saying it. That girl definitely thought I was weird...
  12. FourBanger


    Sep 2, 2012
    SE Como
    If it is something you see when the pickup is installed in the bass it is not a magnet.
  13. ddnidd1

    ddnidd1 Supporting Member

    The round magnets are the pole pieces.
  14. AlNiCo: The pole pieces and magnets are one and the same.
    Ceramic: The magnets are underneath the pickup where you cannot see or touch them.

    The proper fix is to ground the poles, but if that is not an option, then coat them with nailpolish.
    LoveThatBass likes this.
  15. DavC


    May 17, 2005
    Tallmadge , Ohio
    i try to make sure the cavities, even the copper tape or plates , pots, bridge , etc . all get grounded to the same spot ... i'd check continuity on everything ...
  16. This is not necessary. As long as everything is continuous with ground, it doesn't matter where the grounds connect.
    mech likes this.
  17. BassFishingInAmerica


    Jul 24, 2014
    Humming? Maybe you have these guys for neighbors.

    Sorry, couldn't resist.
  18. Ross W. Lovell

    Ross W. Lovell

    Oct 31, 2015
    Not usually. Magnets don't do well with screwdrivers as the magnets with slots would splinter very easily.
  19. pnchad


    Nov 3, 2005
    This is an issue with these strings. I have used LaBella black tape wounds on all my basses for years. My J has always had the typical 60hz hum as a J would when you soloed a pup but would go to ground when the strings are touched = no hum when playing.

    I too put on the copper wounds LaBellas w/ the clear coating - touching string does not ground & eliminate the hum.

    I'm going to have to run a ground up to where I rest my thumb or go back to black tapes unfortunately.
  20. ddnidd1

    ddnidd1 Supporting Member

    Its a Precision pickup. No slots.