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

J-Bass Shielding 101

Discussion in 'Pickups & Electronics [BG]' started by TheToe, Mar 5, 2004.


  1. TheToe

    TheToe

    Feb 2, 2004
    Dayton, OH
    I recently bought a used MIM J-Bass, and it hummed unless I was touching the control plate, knobs or bridge. I'm going to replace the pickups and pots (two stacked pots, and a series/parallel switch), and I've been advised to add some shielding while I'm at it. From what I've read on other posts, I know I should shield the control cavity and the back of the pickguard. What about the pickup cavities? Is there anything else I should be looking at (or be cautious of) while I'm replacing that stuff?
     
  2. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    just make sure the shielding is grounded by a grounding strap, and make sure it doesn't touch any other wires. You'll do just fine.
     
  3. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    For what it's worth, I've shielded two basses and it hasn't made a bit of difference. What I have found useful is to shield the bottom of the cavity which eliminates the need for ground wires between pots which cleans up the cavity.

    I didn't shield the pup bays on the two basses tho. But you're probably thinking like I was, I got this stuff out so I may as well shield it. Which I did on the first one, on the second one I was trying to shut a pair of Duncans up - to no avail. Personally, I'd get rid of the pups and/or electronics before I'd go to the lengths of shielding another one. There's to many good options to fight one setup. The first shield isn't that bad, but after that, I don't think so.

    As I said, for what it's worth
     
  4. Trevorus

    Trevorus

    Oct 18, 2002
    Urbana, IL
    If you feel like going further, you can also shield pickups. I have found that that helps as well in some cases. The stripe of the copper tape would be the best, and it would look cool.
     
  5. bassmantele

    bassmantele

    Jul 22, 2003
    Boston MA USA
    Got to Guitarnuts.com for good advice and instructions on shielding.
     
  6. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    Went to the Guitarnuts site and it looks like a site worth exploring, but it really doesn't tell you much about actually doing the shielding. I thought it might when I read the material list of aluminum foil but they were talking about shielding using aluminum foil.

    I was going to come back and mention some of what I did to mnimize the treat.

    I think you can get copper foil at Michaels but I got mine from Stewmac.com. Selfadhesive backing, you won't need to solder the shield. I used regular household aluminum foil to make a pattern which will get you pretty close. Cut the shiedling accordingly allowing some for overlap during placement, paying close attention to the relationship of how the shielding will actually lay in place - it's easy to cut it backwards so when you go to lay it in place you have your adhesive on the wrong side or a curve going the wrong direction. If you put the bottom down first and then the sides, it's possible to make it look practically seam free, except around the lip where the bay cover fits. If you have a gap, you can throw a piece of shielding over it and work it in, it's no big deal - it just nice to have it look like a pro did it. You're going to be putting in the time regardless so why not. Just go back afterward and cut jack/pot/pup wire holes out with an exacto knife.

    And when you're done, I gaurantee, you'll think whatever techs get for shielding a bass, it ain't enough.

    Enjoy!
     
  7. I did this a couple of years ago on my MIM. it helped a little, but there's only so much you can do with single-coil pickups.

    i went to the guitar clinic, which is where F-Basses are made. they sold me the copper shielding foil, and told me that you have to solder the pieces together. just sticking one to the other doesn't create any electric connection.

    Also, someone recommended grounding the bridge. I believe the original poster's bridge is grounded, because he said that the buzz stops if he's touching the bridge. Mine is from about 96, and it's got a grounded bridge, or it did until i put in my EMG's.
     
  8. luknfur

    luknfur

    Jan 14, 2004
    DIXIE
    "told me that you have to solder the pieces together. just sticking one to the other doesn't create any electric connection."


    My experience so far has been that overlapping the foil does create a solid field and soldering is unnecessary. You can take a meter and check from any pot anyplace on the shield and get maximum continuity readings. I never use ground wires between pots so the shield is the only connection. One set of Duncans has been the only problem and that's definetly in the pups.

    No doubt soldering the foil is an added measure but the shielding is thin and relatively easy to burn through. I haven't ever seen copper shielding soldered at the joints but I have read about doing so.