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Shielding and EMG systems.

Discussion in 'Pickups & Electronics [BG]' started by PhatBasstard, Jun 24, 2004.


  1. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    I'm in the middle of building a bass out of various parts.
    The body is brand new with an oil finish and, as such, has no shielding in the control cavity.
    I'm installing an EMG system (BTS System & PJ pups).
    I thought I may have read somewhere that EMG systems don't require separate shielding.

    Can anyone confirm or refute this?
    I've owned several basses over the years with EMG systems and never bothered to notice if the control cavity was shielded.:rollno: :help:
     
  2. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Any system can benefit from shielding. However, EMG pickups tend to be more resistent to noise than other pickups.
     
  3. Grounding for all the components, yes. But don't worry about the bridge ground, in fact EMG says not to do it. As far as the shielding goes, I always tell people that it may not help, but it will not hurt either.
    I use the black shielding paint for the cavity, and the shielding tape for the inside back of the control plate covers. Make sure that if you use several pieces of tape to cover the entire surface of the cover, that you overlap them and score/rip several holes through where they overlap. You need to do this because the sticky side will not allow the ground curcuit to pass through!
    Good Luck! :hyper:

    Dave Starr: Bassist with CHASTAIN & Vicious Rumors
     
  4. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    Thanks,
    I already knew about the bridge not needing the ground.

    On the second part, this body is rear routed.
    Does this still apply because I'm not really getting a clear picture on the "ground circuit to pass through" statement?
     
  5. Nino Valenti

    Nino Valenti Commercial User

    Feb 2, 2001
    Staten Island NYC
    Builder: Valenti Basses
    According to the EMG instructions that I've had, you don't need to use any shielding. I've installed EMG's in a bunch of basses with out shielding with no problems.

    Lateley, I've been shielding all the basses I've built just to be on the safe side. Make sure that connect the p/u cavities to the control cavity. If you're using paint, use a Q-tip to paint the hole. If you're using tape, you should be able to soilder a wire directly to the tape.

    [​IMG]
    [​IMG]
     
  6. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    ...because the inner part of the tape (shielding) is conductive! (Doh!:p )
    The previous post about ripping and scoring the tape so the ground circuit can get through suddenly makes sense.

    Thanks guys.
     
  7. YOU GOT IT! I figured I would let you dwell on that for a bit! It's just that you need to break through that sticky film so that the 2 metal tape pieces make some contact.
    Also, If you bring the paint all the way up the cavity and over the lip where the control plate site in, you will not have to run a ground wire from the pots to the tape. :hyper:

    Dave Starr: Bassist with CHASTAIN & Vicious Rumors
     
  8. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    I've just never used the tape before.
    It didn't click right away.
     
  9. Depends what type of tape you're using. The type Stewart Macdonald sells has conductive adhesive. In any case it makes sense to check electrical continuity of your shielding with a meter.
     
  10. Schwinn

    Schwinn

    Dec 4, 2002
    Sarasota, FL
    Yes, the sticky side of the tape sold by Steward McDonald IS conductive. I recently sheilded a bass with it and tested it with a volt meter. It's great stuff, it eliminated a problem I had with a buzzy pickup.
     

  11. WOW, that is news to me! The suff that I get from ALLPARTS is not!! :eek:


    Dave Starr: Bassist with CHASTAIN & Vicious Rumors
     
  12. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    OK, next dumb question:

    Can I find the paint and tape at someplace like Home Depot,
    or do I have to go someplace special?
     
  13. Schwinn

    Schwinn

    Dec 4, 2002
    Sarasota, FL
    I think it would be really hard to find that stuff even in a music store. Home Depot won't have it since it is made especially for guitars. Stew MacDonald or Carvin is the best bet.

    Here is the tape I used with great results:

    http://www.stewmac.com/shop/Electronics,_pickups/Supplies:_Shielding/Conductive_Copper_Tape.html
     
  14. xyllion

    xyllion Commercial User

    Jan 14, 2003
    San Jose, CA, USA
    Owner, Looperlative Audio Products
    Copper foil tape is also used in stained glass construction. You can get it from any store that sells to stained glass hobbiests.
     
  15. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    Thanks for the link.
    I wonder if an industrial supply house or really good electronics supplier (not Radio Shack) might have it, because I have to believe there are some other uses for it other than just guitars.
    Usually something that would only benefit a percentage of the music industry would not be profitable enough to develop nor manufacture.
    Other than woodworking and molded plastic or metal parts, about everthing (technology wise) used in the music industry is an offshoot of manufacturing for the larger world (I smell another thread coming on).
    Thanks everyone.
     
  16. Schwinn

    Schwinn

    Dec 4, 2002
    Sarasota, FL
    I'm sure you could find plenty of other uses for that tape and paint. And you could probably find materials that will shield a guitar made for different purposes. But why not get the stuff that is made for the purpose of shielding a guitar? That should work as good if not better than anything else, since that is what you want to use it for. It's an interesting question you ask anyway.
     
  17. A9X

    A9X

    Dec 27, 2003
    Sinny, Oztraya
    I've been building RF and studio gear for a loooong time, and I can't imagine what's so special about the tape Stewmac sells. I make control cavity sub-enclosures out of thin copper or brass sheet that I buy from modelling hobbyist stores, and as someone mentioned previously, stained glass suppliers. I shape a bottom and sides, solder it all together, drill the holes for pots/switches/wires etc, then coat it in a varnish, so the copper doesn't oxidise. I also make sure there is a lip at the top edge so that the lid (of the same material) makes good electrical contact. The other trick is to make sure all the <i>grounds</i> are connected together at <b>one point only</b>; the battery clip negative usually works well.

    I did this to a friends old Gibson LP geetar this week, and I reckon the noise/hum floor dropped over 20dB. She's stoked, and it cost about $US5 in parts and maybe 2 hours.
     
  18. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    Good info. I may consider this route.
     
  19. PhatBasstard

    PhatBasstard Spector Dissector Supporting Member

    Feb 3, 2002
    Las Vegas, NV.
    Well, as far as EMG systems and pickups go, I guess you don't need it.

    I installed everything with the bass unshielded and it's totally quiet.
    I get close to the stereo, TV, Neon lights, etc. and nothing.
    Absolutely no hums or buzzes what so ever.
    Cool.:cool: :cool: