Complex wiring - split pickups with dual 5 way

Discussion in 'Just Pickups' started by hoglundtw, Sep 7, 2020.

  1. hoglundtw

    hoglundtw TDPRI Member

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    OK - I got inspired seeing some split pickups available on eBay and am using these in an Airline type body build and need help on what is probably the most complex wiring question I've ever dealt with.

    The pickups are each 3 strings wide and individually 3.5 Ohms. I have 6 in total. Want to wire them up similar to standard Stratocaster wiring, but with two 5 way switches to control the lower pitched strings versus higher pitched string sides of the pickups separately. Only one tone and volume to simplify things.

    The goal is if I switch the two 5-ways to the same positions, I'll get normal Strat pickup combinations, although I'll wire them reverse polarity so they will noise cancel. If that was all I wanted, I'd just wire the two halves directly in series with each other and could just use one 5-way switch and it would be like normal Strat 7 Ohm pickups.

    But I also want to be able to take advantage of the split pickups to get combinations I couldn't otherwise get. E.g., Neck pickup for the 3 lower strings at the same time as bridge pickup for the 3 higher strings.

    I'm attaching pics of the build, the way I've wired it and the schematic I thought would work. Haven't strung it up yet, because I'm finding that the multimeter shows me I have 30+ Ohms resistance when I put both switches to the same position (e.g., bridge) rather than the 7 Ohms I was expecting. Slight drop when I go to position 2 or 4 as you'd expect, but still way higher than I was postulating. So something's wrong with my thinking here. Airline build.jpg View attachment 761374 Airline Schematic First Try.jpg

    Can anyone help?
     

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    Last edited: Sep 7, 2020
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  2. Deeve

    Deeve Poster Extraordinaire Silver Supporter

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    Wow - just wow:cool:
     
  3. AJBaker

    AJBaker Friend of Leo's

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    You should be ok, I'm guessing, just wire the switches up like you had two strats, then wire the switches to the volume pot.

    You'll only measure 7k if you wire them in series, but I wouldn't worry about how many ohms you measure.


    In any case, let us know how it turns out! Seems a bit crazy, but might be great!
     
  4. hoglundtw

    hoglundtw TDPRI Member

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    IF I did it the way you suggest, then won't the two sides be wired parallel to each other and I would get only 1.75 Ohms net output when, for example, both were in bridge position and wouldn't it sound really anemic at 1.75 Ohms versus a normal pickup being more like 7 Ohms plus??
     
  5. Digital Larry

    Digital Larry Friend of Leo's

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    That's a head scratcher. Don't see how anything adds up to 29. However we're talking "k" ohms here right?
    I would not expect the switches together to really sound like a normal Strat. Except in positions 1, 3, 5.
    Each switch makes a combination of 1 or 2 pickups, but then that is put in series with the other half.
    In pos 1, 3, 5 it wouldn't matter as those are just 1 pickup anyway.
    In 2, 4 you'd have 2 sets of half pickups in parallel, in series with each other, rather than 2 half pickups in series (if you wanted to think of a single pickup this way) in parallel with each other.

    N1 = neck 1
    N2 = neck 2
    M1 = middle 1
    M2 = middle 2

    In general, impedance A in parallel with B results in:

    (A * B)/(A + B)

    regular Strat = N1+N2 || M1+M2

    (N1 + N2) * (M1 + M2)
    ---------------------
    N1 + N2 + M1 + M2

    split Strat = N1 || M1 + N2 || M2.

    (N1 * M1) (N2 * M2)
    ---------- + ---------
    (N1 + M1) (N2 + M2)

    yeah, I'm not gonna figure the whole thing out. But I doubt it. But it might sound cool! Screw math anyway!
     
  6. AJBaker

    AJBaker Friend of Leo's

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    Ohms don't matter for calculating output, unless all other factors are the same.

    Think about it: a strat pickup might measure about 6k. When you set the switch to the famous inbetween position, you're only going to measure 3k at the jack.

    Is the inbetween position anemic and only half as loud as one pickup by itself? Of course not. You're just getting a low reading because you're measuring two pickups at once.
    It's a bit like standing on two bathroom scales at once with each foot on a different scale. Each scale will only show half your weight, but you still weigh as much as you did before.
     
  7. AJBaker

    AJBaker Friend of Leo's

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    Furthermore, your 3.5k pickups only measure so little because the bobbin is so small. It might have the same number of turns (and therefore a similar output, all else being equal) as a strat pickup measuring 6k. But because the bobbin is so small, each turn uses less wire, so you have less resistance at the end, despite the output possibly being equal.
     
    Last edited: Sep 7, 2020
  8. AJBaker

    AJBaker Friend of Leo's

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    And to conlude on why Ohms are completely useless unless all other factors are equal, think about the early 50s tele pickups that at various times used 42AWG wire, or thinner 43AWG wire.
    An early pickup made with 43AWG might measure 9k, and a later pickup made with 42AWG might measure 7k, despite both pickups having the same amount of turns and similar output.

    A strat neck pickup (42AWG) measuring 6k is almost always more powerful than a tele neck pickup (43AWG) measuring 7k.


    For your project, I bet both the series and parallel sounds could be interesting to explore, and I'm willing to bet the parallel positions will sound just fine.

    Good luck and let us know how it works out!
     
  9. jvin248

    jvin248 Doctor of Teleocity

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  10. Zepfan

    Zepfan Doctor of Teleocity Gold Supporter

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    Tiesco Spectrum guitar used split pickups like that, but they had individual on/off for each pickup.

    You may want to consider a Freeway switch.
     
  11. Zepfan

    Zepfan Doctor of Teleocity Gold Supporter

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    One set of 3 to a 5 way switch and another set of 3 to the other 5 way and both output wires to 2 separate volumes to a shared tone, 2 tones or no tone to the jack.
     
  12. Digital Larry

    Digital Larry Friend of Leo's

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  13. tfarny

    tfarny Poster Extraordinaire

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    I like your wiring idea, original and potentially interesting possibilities! And I don't see any real issues with your approach. One thing you might consider is to string it up and see what actual sounds you are getting, not worrying about the multimeter for now. If things sound wonky you can then take an ohms reading and do detective work from there. It could be a funky pot or something else loading up the system. Or one of those pickups might be defective....But your diagram in theory should work great!
     
  14. sluglas

    sluglas Tele-Meister

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    You just need a a standard 5-way switch and a dual pole 5-way switch IMG_20200913_092918928~2.jpg The in between settings on let's say ( bridge and middle) would put two coils in parallel before running in series with the coils on the second switch. Be interesting to hear the two coils in parallel going
    into just a single coil on the second switch.
    Enjoy!
     
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