Squier Precision Bass wiring problems

Discussion in 'Pickups & Electronics [BG]' started by fschuindt, Dec 14, 2014.

  1. fschuindt

    fschuindt Guest

    Dec 14, 2014
    Hello guys,

    That's my first post in this forum, I've tried to find the more appropriated section and so I decided to post here.

    I have a Squier Precision Bass, I bought it from a guy in the internet 4 years ago.
    At the time it was fine, but then my tone and volume pots started to fail. I know a little bit about electronics and love the "DIY spirit" so I decided to fix it on my own.

    I decided to make a whole new wiring with new pots, capacitor and jack.
    I followed this chart:


    The first problem: Log(A) and Lin(B) pots;

    I found in the internet that the Fender's standard is to use Log(A) pots.
    But inside my bass I found a Log(A) pot "250KA" in the Volume and a Lin(B) "B250K" in the Tone.

    I guess that's pretty strange, but my two brand new pots is both Log(A) "250KA". I think that's better, right?

    The second problem: The capacitor;
    As the picture says it's a .047uF 100v.
    100v is pretty rare to find and I heard that the voltage don't matter that much, may I am wrong.
    I really wanted to use Sprague Orange Drops, so I bought two "47KPF 600V CAPACITOR ORANGE DROPS S715" which I calculated as .047uF, right? I am still waiting the delivery.

    I found in one old broken pedal board some polyester capacitors marked as "F74 473J", as the name 473J stands for 47000pF, that's .047uF, is the same capacitor, right? So I decided to try it before the Orange Drops arrive, and well, lot of noise when I release the tone knob. :(

    I know I am making some mistakes, (I must) hahaha
    But trying to find some help, anyone?
  2. Tone pots need to be audio. Volume pots are a personal preference. Try both tapers and see what you like.

    Voltage doesn't matter in this application. Even a lowly 100V can handle about fifty times more voltage than it is ever going to see. 600V works, but is unnecessarily large, in terms of physical geometry.
  3. fschuindt

    fschuindt Guest

    Dec 14, 2014
    There's my circuit layout right? I don't understand why it's noising :(
  4. Make sure you do not have the output jack wired backward.
    Make sure the bridge is touching the ground wire under it. A volt ohmmeter would help here
  5. fschuindt

    fschuindt Guest

    Dec 14, 2014
    The jack was indeed wired backward, thank you very much.
    The bridge wire as ok. I changed the jack wires positions but still with lot of noise.

    I am starting to think that is something wrong with the layout or with the capacitor, the pots are brand new.
    I will wait for the Sprague Orange Drops to test, but I am still worried.

    Is this circuit picture right? I have seen some different layouts like this:

  6. ex-tension


    Jun 11, 2009
    The problem with the layout is the grounds are not connected together. These layouts assumes that you have some conductive foil under the pickguard where you mount the pots. Sometimes there is, sometimes there isn't. And sometimes the pot bodies doesn't have a good contact with the foil.

    Connect those "solder" blobs (at the back of the pots) together with a wire:

  7. The volume pot must have a ground wire connecting its case to the tone pot case 5he to ground on the output jack.
  8. Hopkins

    Hopkins Supporting Member Commercial User

    Nov 17, 2010
    Houston Tx
    Owner/Builder @Hopkins Guitars
    The pots have to be grounded, the point in which they are grounded doesn't matter.
  9. fschuindt

    fschuindt Guest

    Dec 14, 2014
    That was the problem! Thank you!
    Thanks everybody who posted here, really nice help! :hyper:

    My bass is talking again, hahaha, awesome!
    Last edited: Dec 15, 2014