Bass wiring emergency

Discussion in 'Pickups & Electronics [BG]' started by Uncle Amos, Dec 4, 2005.

  1. Uncle Amos

    Uncle Amos

    Sep 3, 2004
    Here's a quick summary: First I bought an Essex '75 Jazz bass with intent to modify it, then I bought some pots and shielding tape from Stewmac in hopes of wiring my bass in V/B/T with a small ON/ON switch for series/parallel.

    I wanted to use This Schematic.

    Now for my problems:

    1. Shielding Tape: I can see that my bass has some shielding paint splashed on it. Do I have to sand the paint away before applying the tape? Also, do I have to tack and solder the tape down once applied? any other tips?

    2. My pickups: As you can see from that schematic, it requires two wires (hot and ground?) from each pickup, but my pickups only have one wire from each. What do I do?


    Please reply with your help. My bass is waiting all cracked open with strings removed.
     
  2. No, you don't have to sand the shielding paint off. And just make sure the tape somewhere is in contact with a ground. You don't have to worry about soldering or tacking the tape to itself, as long as one piece of tape contacts the next piece of tape (the glue was conductive on my roll).

    There's gotta be two wires on the pickup, they might be in the same jacket, but there's gotta be two wires...they might be shielded coaxial wire, which means there would be a central wire with a braided wire shield around it--the braided wire is the ground wire and the central wire is the positive wire.
     
  3. Uncle Amos

    Uncle Amos

    Sep 3, 2004
    So what do I do if the schematic calls for two wires from each? That's what I need to know.

    Thanks.
     
  4. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Pasco, WA
    As long as the tape sticks o.k., you can leave the paint.


    It depends on the tape that you bought. Some tape is conductive through the glue and some isn't. See if it says on the package. If it is not then you will have to tack 'em together.

    Use as few pieces of tape as possible. The bigger the better.



    There's definitely two wires coming from your pickups. Check if it is being grounded somewhere else than the control cavity. Also check and see if you have a center conductor/braid cable. The center conductor would be hot and the braid/shield would be ground.

    Good luck!

    :D

    Joe.
     
  5. Uncle Amos

    Uncle Amos

    Sep 3, 2004
    Okay. I took a second look at my pickups and I see what you are talking about with the white + wire surrounded by the "braided" wire. Now that I have that figured out I still have the same question. What do I do with the schematic I have?
     
  6. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Pasco, WA
    The black wires coming from the pickups on the schematic would be the center conductor on your pickup wire.

    The white wires coming from the pickups on the schematic would be the ground wire or braid of your pickup wire.

    :D

    Joe.
     
  7. Uncle Amos

    Uncle Amos

    Sep 3, 2004
    .......Yes, I said that I understand that.

    What I need help with is figuring out what to do when it come to wiring everything. Do I somehow seperate the conductor wire from the ground wire? If you look at the schematic you'll see that the two wires are connected to different places. I need to do that if I plan on following the schematic's directions. :help:
     
  8. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Pasco, WA
    Oh.

    Yes, you can either strip it down and unravel the braid far enough to reach where you need to go or just solder a wire to the braid and then run the wire to whatever terminal you need it to go to.

    The second choice might be the best way to go.

    But whatever you do make sure that the exposed braid does not come into contact with the rest of the wiring.
     
  9. Uncle Amos

    Uncle Amos

    Sep 3, 2004
    hmm.....I might just order those Dimarzio Ultra Jazz pups which I'm certain have the two seperate wires...

    Thanks for your help.
     
  10. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    That's backwards, which I guess your smiley implies, but I wouldn't want the original poster to try it backwards.

    Braided shield = black

    Center white conductor = white
     
  11. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    It's not a good mod to do with pickups that use a braided shield for the negative lead, since that braid can easily touch other grounded components, especially if you shield the cavities.

    Ultra Jazzes are great, and you can certainly use them. Or you could replace the stock leads on your current pickups with separate leads.
     
  12. OK, this is the way to deal with that cable. It is called coaxial cable, or just "coax". Pron. "coe-axe", not "coaks"

    Do it like this:
    1. strip off about an inch of insulation
    2. using a blunt pick (they come in soldering tool kits) separate the braid just above where the insulation ends. You want to make a hole but not break up the fine braid wire. Be patient and you will have a nice open spot where you can see the insulated center conductor.
    3. Make a bend in the cable so that the center conductor pushes against the hole you just made.
    4. Use the same tool to get under the center wire and pull it through. The best bet is to get the tool under both sides and then work it out through the hole.
    Done!
    Smooth the braid down and be careful with heat since it will melt through the center wire insulation if you aren't careful. You will probably want to solder up some small extensions into the pickup leads. Get some small heatshrink tubing and some good electrical tape. You don't want exposed braid flopping around in there.

    But it sounds like you have some other hurdles to clear on this project.... If you go with UJ's then you will have 4 conductors per pickup! :crying: Also, that is a diagram, not a schematic! There is no end to the hall of mirrors you have stumbled in to. :ninja:
     
  13. Lyle Caldwell

    Lyle Caldwell

    Sep 7, 2004
    Memphis
    Heh. Yeah, it's a diagram. Most people can't read a schematic, but they can read the diagram. The UJ 4 wires are easy to deal with.
     
  14. That's very true about braided coax, but the stuff on SX pups is not braided, it's just twisted coax. Once you strip the outer jacket, the shield wire will just come away ;)
     
  15. Lowtonejoe

    Lowtonejoe Supporting Member

    Jul 3, 2004
    Pasco, WA
    Whoops!

    My mistake, I stand corrected.

    Didn't take a close enough look at the output jack.

    :D

    Joe.