Series/Parallel wiring issues...

Discussion in 'Pickups & Electronics [BG]' started by adamrobertt, Jul 16, 2021.

  1. adamrobertt

    adamrobertt Supporting Member

    Dec 14, 2007
    Hey guys. I'm wiring a J style bass with master volume, pan, and passive tone. The master volume is a push/pull switch that I'm trying to wire for series/parallel.

    I used this diagram:

    Everything is wired correctly but the circuit does not work as intended. I get no output in any position except that the bridge pickup works when I pull up on the push/pull. In all other positions I get no sound at all. Anyone have any ideas on where I went wrong? The pickups both tested at around 9k, so I know they work fine. Any help would be appreciated.
  2. I hate it when that happens LOL.

    While the bridge is working (push/pull in up position), does the volume, blend, and tone control work properly on it?
  3. dwizum


    Dec 21, 2018
    Crater likes this.
  4. sunbeast

    sunbeast Supporting Member

    Jul 19, 2006
    Denver, CO
    The diagram as drawn should work fine, so we are left to troubleshoot what may be miswired or other possible complications. Can you post a picture of your actual soldered connections? Do you have a multimeter to utilize to verify that connections are made? What pickups are you using? Do the pickups have any internal shielding or just standard traditional J pickups?
    I assume you have the two jumpers making the “x” across the blend pot (red and blue in this picture)? When the bridge pickup is working does rolling the blend all the way to the neck side turn the bridge pickup off or is it still audible (in other words, does the blend essentially just act as another volume control for the bridge pickup or are there oddities with how it works?)? What are you using to make the “ground” connections (like the back of pots? And how are your pots themselves grounded?)?

    Easy things to check are both the neck pickup lead connections, as well as checking that the switch is making the correct internal connections using your multimeter and isn’t damaged (cheaper push-pull switches are easy to overheat and damage )
    Last edited: Jul 18, 2021
    fig likes this.
  5. adamrobertt

    adamrobertt Supporting Member

    Dec 14, 2007
    The pickups are Bartolini single coils with two conductor wire. All connections are sound with a multimeter, and the pickups both test right around 9.3k.

    All grounds are connected to conductive copper foil, and the bridge ground is connected to the volume pot. Def not low quality pots, they're all Bourns. I double checked my connections like 10 times and they're definitely correct, although you just got me thinking about the pan pot...

    Normally when I wire them, one of the "x" leads acts as a ground on both sides, and the other side connects both sides of the pot together so that they act in conjunction (but opposite) to one another. But I'm just realizing that the top left of the red lead on the "x" in the diagram is not actually supposed to be connected to ground, just the bottom. I suspect that this is most likely my problem. Does that make sense? This stuff is hard to explain in words, hopefully I made sense.
  6. dwizum


    Dec 21, 2018
    If the red marker line on the diagram is a wire then it won't matter if you connect the ground to the top left or the bottom right.
    fig likes this.
  7. I'll assume for the moment that if the bridge pu is only working when push/pull is up, that the controls (Master Vol, 1/2 of Blend pot, Master Tone) work as they should (I asked earlier). Pretty much what @adamrobertt is asking, but I have a pretty diagram LOL.

    If yes, everything in green is ok.:

    Note that 4 of 6 contacts on the push/pull switch aren't greened. Deck 1 of the Blend pot also isn't greened. Check the internal workings of those with your meter as those areas could be the problem.

    And I know you checked resistance of the pickups, but maybe verify the actual Neck PU output unless you already know it works. Connecting it directly to the output jack is one way.

    Anyway, this is a start. Hope it helps.

    The one thing I don't like about this version is when Series is selected, only Deck 1 of the Blend Pot is used. That means only 1/2 of the full pot rotation of Deck 1 will be usefully controllable. The other half of Deck 1 will be full on all the time.
    Last edited: Jul 18, 2021