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2 pickups, 2 vol, 2 tone, 1 series/parallel switch. Help?

Discussion in 'Pickups & Electronics [BG]' started by StarbardGuitar, Apr 5, 2014.

  1. StarbardGuitar


    Feb 18, 2013

    Some of you may have seen the build I've been doing for the past couple months, and now that I'm getting toward the completion I realize I can't find a schematic for the wiring set up I'd like. I also don't know enough about wiring and electronics to figure it out myself. I'm hoping someone might be able to help me!

    I have a Seymour Duncan SMB-4A (MM style) bridge pickup, and a SD Classic Stack (J-style) neck pickup. Both are 4-conductor. So here's what I'd like to do:

    Each pickup has its own volume and tone.
    The neck pickup is wired in series (it is a stacked humbucker).
    The bridge pickup has a mini switch for series/parallel switching.
    When both pickups are on I'd like them to be whatever they would be on a jazz bass (I can't remember if together they are in series or parallel...)
    No preamp or anything, and it just goes to a mono jack.

    Can anyone draw up a schematic I could use for that? Or any advice on what to do? If I go on Duncan's site, I can find things like their wiring set up for 2 of the hum canceling j-style pups with 2 vol's and 1 tone. I can also find a schematic for how to wire a series/parallel switch. The part I don't know is how to wire 2 individual tones instead of one master. Is there maybe a simple explanation on how to do this?

    Basically, looking at this diagram, what would have to be changed to get individual tones? That might be easier than drawing up a new schematic. http://www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=jazz_bass_stacks

    Thank you!
  2. Having two tone controls is not going to work out well unless you find some compromise that you are happy with.

    With both volumes up, there will be no isolation between the tone controls. Rolling a volume pot down will provide increasing isolation for its pickup's tone control, however. If you want the tone controls to function independently at all volume settings, you will either need to buffer the signal paths, or add resistors to isolate the signal paths. Buffering requires a battery, and comes with certain disadvantages. Using resistors will cause volume drops.
  3. StarbardGuitar


    Feb 18, 2013
    Okay, so now my question would be how do indivudal tones on Strats or Les Pauls work? That's where I got the idea from. I'm not looking to use individual tones when both pickups are on for different settings or something. I just wanted to have individual tones so each pickup had its own complete control, so I could have for example: The bridge pickup soloed, with the tone full on; then switch to the neck pickup with the tone rolled off, only by adjusting the volumes. Does that make sense?

    Also, should I maybe just forget the idea, and do a master tone? The problem is that I've already drilled for the pots & routed a LP style control cavity. I don't know what I could put in place of that hole.
  4. On a Strat, there is a pickup selector switch that switches the tone controls. They share a capacitor, and when the neck and middle pickup are used together, both controls do the same thing.

    On a Les Paul, there can be two tone controls when both pickups are used together, but they only function independently if the volumes are turned down. Both affect the same signal, otherwise. Sometimes it is not obvious that the tone controls do the same thing, because there are two capacitors, so the capacitance can increase when using both controls together. Furthermore, the use of differing capacitances can make the tone controls sound different from each other, even though they do the same thing.
  5. StarbardGuitar


    Feb 18, 2013
    Okay I suppose that makes sense. But I'm not worried about that. Like I said, I'm not planning on using both tone controls with both pickups on full volume. I always found that I only use the tone controls on a pickup when it is soloed. That's why I want to use two tones.

    Can anyone draw up a schematic or point me in the direction of how to add a tone pot to the existing SD schematic I posted?
  6. 3945260143_aa91c27bae_o.
  7. StarbardGuitar


    Feb 18, 2013
    Thank you both!

    Line6man, you have me thinking now haha. I suppose I don't really need independant tone knobs. So now I'm considering my options as my finish is curing. Would it be possible to have 2 volumes, 1 tone, and a blend pot? I feel like blend pots typically are used with a master volume.