hiss when touching pup magnets

Discussion in 'Pickups & Electronics [BG]' started by orenp, Mar 13, 2018.

  1. orenp


    Jul 15, 2017

    In two of my jazz basses which have exposed magnets I experience an audible hiss when toughing the magnets. My electronics intuition tells me that I should ground the magnets. Elsewhere I read that it is common issue which is treated by covering or applying lacquer to the magnet to isolate them from touch. The basses are Fender Deluxe Active Jazz Bass V (MIM) and Fender American Deluxe Jazz Bass, and they are both wired correctly as compared to the charts.

    What is your experience?

  2. Killed_by_Death

    Killed_by_Death Snaggletooth Inactive

    My experience is that grounding the pole pieces is like putting a wet blanket over the output. It takes away the highs, at least it did on my Mexican Fender Blacktop.
  3. 96tbird

    96tbird PLEASE STAND BY

    So stop touching the mags!
    JK. Clear Fingernail polish on the magnet ends. Just a thin coat or two. Remove the cover first so you can coat the tops and sides to cover a good amount of suface for good adhesion.

    If you are used to working with CA, you can do the same with thick CA which adheres better.

    Niether will affect the signal.
    ELynx and DiabolusInMusic like this.
  4. fermata

    fermata Guest

    Nov 10, 2015
    Just to offer a contrary view, I've grounded pole pieces on two different basses, which eliminated the hum without causing any detrimental side effects. Shielding tape or aluminum foil does the trick.
    DiabolusInMusic likes this.
  5. Slater

    Slater Leave that thing alone.

    Apr 17, 2000
    The Great Lakes State
    Don’t the MIM Fender Deluxe Active Jazz Basses have Fender Noiseless pickups? If so, you can’t ground the pole pieces, as the pickups are epoxied together and the pole pieces aren’t exposed on the bottom.

    I would try the lacquer/nail polish trick. Cheap and easy.
  6. orenp


    Jul 15, 2017
    Sorry, what is CA? I imagine you didn't mean calcium :) maybe Cellulose acetate?
  7. orenp


    Jul 15, 2017
    Actually the MIM Fender Deluxe Active Jazz is an older model (96 I believe). The original pup was (quoting from wiki Fender Jazz Bass V - Wikipedia) "Models produced before 2004 came with Suhr-designed "single pole" stacked humbuckers". I've replaced these with Aguilar AG 5J-60.
    Slater likes this.
  8. fermata

    fermata Guest

    Nov 10, 2015
    CA=Cyanoacrylate Adhesive=Super Glue.

    A small dab on the pole serves as an insulator.
    Edit: A piece of electrical tape will serve the same purpose, either as a temporary experiment or a permanent solution (depending on the aesthetics).
    Last edited: Mar 20, 2018
  9. DangYankee


    Jul 11, 2017
    East Texas
    Lol, just say that the first time man :)
    Killed_by_Death likes this.
  10. JRA

    JRA my words = opinion Gold Supporting Member

  11. Axstar

    Axstar Inactive

    Jul 8, 2016
    The fumes might produce a white, misty discolouration on the cover of the pickups. This disocolouration comes off poly finishes with acetone, but acetone would likely start eating into the pickup cover. A small quantity of 2-part epoxy, applied to each pole in turn, would be a safer bet.
  12. DiabolusInMusic

    DiabolusInMusic Functionless Art is Merely Tolerated Vandalism

    You seem to know exactly what is up. You need to ground your pole pieces. You can do this either with a strip of copper tape to ground them or some clear nail polish to prevent contact with them. I have done both.
  13. 96tbird

    96tbird PLEASE STAND BY

    Dude, this is the big leagues now. We use proper nomenclature around here when referring to the tools and supplies used, not cursive. Savvy? :woot:
  14. orenp


    Jul 15, 2017
    OK, tried the nail polish. Didn't work. Don't know why. The nail polish isn't conducting checked it. Can someone point to or upload pictures of a grounding job well done?
  15. Yeah, try earthing the magnets from the bottom. The trouble with this is that pickups such as duncans and others will have foam glued to the underside, and this is a bit of a pain to remove completely. Also, IME the copper tape, even if it boasts conductive adhesive, doesn't stay reliably electrically connected with the bottoms of the magnets in the long term. Your best bet for a permanent solution, is to use a piece of copper tape so a wire can be soldered, but actually use conductive paint on the magnets and overlapping onto the copper tape.

    Another approach is to simply swap both the wires on both the pickups. If the inner windings (start) of the coil is at earth, then the hum is far less. With a pair of jazz bass single coil pickups that are "reverse wound", you should be able to wire them in-phase, hum-cancelling, and both will have the inner windings to earth.
  16. micguy


    May 17, 2011
    Good copper tape will stay stuck (especially if you have foam under the pickup pushing on it) and be conductive - it's what you need. Your bass will be a bit less noisy, so yes it'll "sound different" , but the tone of what you are playing and want to hear won't change, unless what you want to hear is buzz.
    96tbird likes this.