Double "P" Theory

Discussion in 'Pickups & Electronics [BG]' started by RED J, May 26, 2012.

  1. RED J

    RED J Lol

    Jan 23, 2000
    I wonder what our pickup experts will say about this idea:
    I've read about the wider pickup aperture effect on tone. What, if any effect would come from putting two P pickups back to back?
    Offset in the normal manner, but two halves on each side. Wired one coil (of one pickup )each side or both coils (of one pickup) on one side. Forgive me this moment of insanity, just can't help but wonder. Maybe even wired so you can select outside coils either side.
    Can't be any crazier than four lipsticks, one per string, per Italia config.
  2. Somehow this sounds very interesting, I have to admit myy interest is piqed!
  3. Bruce Johnson

    Bruce Johnson Commercial User

    Feb 4, 2011
    Fillmore, CA
    Professional Luthier
    If I'm understanding you correctly, that's sort of what I've done with the "M-pickup" on my Series IV Scroll Basses. It's four independent coils, one for each string. Each coil is tall and narrow, with three 1/4" dia Alnico V magnets. The coils are arranged along the strings, so the aperture along the length of the string is quite long, but the aperture across the string is fairly narrow.

    The result? I would describe it as being both rich and smooth. It's a great combination for use with flatwounds. The long lengthwise aperture tends to pick up more of the background subharmonics and coloring than a typical P or J style coil.

    At the same time, it tends to level out the various harmonics as you go up and down the fingerboard. They are more equal, rather than some being brighter or deader. I think that's because, with a narrow lengthwise aperture pickup (like conventional P and J coils), you can find notes where the nodes and anti-nodes end up directly over the center of the coil. That's what causes some harmonics to be loud and others quiet. With my long aperture coils, that effect is reduced. A Node may end up somewhere over the coil, but further along the coil, there's enough string deflection to level it out.

    I wondered what the effect would be of the fairly narrow sideways aperture. I was surprised to find that it tends to increase the percussiveness. A little more pop in the attack. I'm not sure exactly why, but I guess it's because there's a lot of wire in a narrow space.

    If you're wondering, the main reason I developed this pickup was because I wanted to go with a 4" radius fingerboard on the Series IV model. Obviously, no conventional coil pickup would work with that round of a radius. Rather than use little round coils like Ampeg did with their AMB-1, and Wal did later on, I decided to experiment with the long narrow coils.

    Maybe this answers some of your questions? This is a specialty pickup, great for this particular application, but it's not for everyone.

    Attached Files:

  4. RED J

    RED J Lol

    Jan 23, 2000
    I think it nails the gist of what I am thinking about.Yours being a purpose designed version of the cobbled sort of application I was describing. My thought was inspired by the concept of a Jazzmaster guitar pickup, where the wider, flatter design was supposed to have a similar effect. I guess MM style bass pickups fit into this concept as well.
    Seems I have seen a four coil bass pickup with selectable coils that uses this concept, where selecting a "standard P" stagger or "reverse P " stagger could be chosen, as well as all four coils at once. I just cant remember where. Your design is intriguing and impressive !
    Thanks for sharing your design and knowledge, I'm just a tinkerer who loves to experiment.I've always appreciated your Ampeg scroll refinements, Maybe someday...
  5. danomite64


    Nov 16, 2004
    Tampa, Florida
  6. moonshinegtrs

    moonshinegtrs Inactive Commercial User

    Jan 28, 2009
    White Bluff,Tn.
    Owner: Moonshine Custom Guitars
    You post caught my eye.

    This is a protoype that I am building now (actually building two at the moment; a customer spotted this one & purchased it. the second one will be my personal bass as well as a test instrument):

    I have been waiting to post pics until it (they) were completed, but after seeing your post, this seems as good a time as any.

    The pickups on this one will be GFS "Hot" P models; I will most likely use Seymour Duncan SPB3s on mine. The controls are passive; two volumes (one for each set of p/u's, jazz style), master tone & there will be two switches (mounted close to the bridge); selector switches for both sets of coils.

    If I am guessing right, this is close to what you are referring to.

    The whole idea is what (I think) you were talking about; to be able to select which coils you want (inside set, outside set or even all four together). It will be interesting to see how it works out.

    They have bolt on 31" scale necks. These two have solid swamp ash bodies; I plan on building some semi hollow and with other body woods (alder; which will be painted, Spanish cedar) as well as some with my take on Dano/J.J. style construction. These will also be available with a single humbucker. I have been collecting Peavey T40 pickups that I believe will work well on this style of bass; I also have a Darkstar that I have been saving for a special project.

    Moonshine :bassist:
  7. RED J

    RED J Lol

    Jan 23, 2000
    Dano, it may have been Enfield. Not sure.
    Moonshine, your design is in the same ballpark, just picture two halves stacked one on top of the other on E-A, two more D-G, were more what I had in mind.
    I guess that means the vertical spacing or aperture in my idea would be less, I guess the proof would be in testing both in a swimming pool rout to find out which flavor you like.
    Bruce's design definitely describes what I hoped would be the result tonally.
    The enfield design is pretty intriguing. Again, I'm just a tinkerer, I don't know all the electrical / electronic implications.
  8. danomite64


    Nov 16, 2004
    Tampa, Florida
  9. tspallone


    Oct 13, 2011
    Nanuet, NY
    Wow, had to stop and think about what's going on with this one. Very cool.
  10. wooodhead


    Jul 16, 2011
    Hungary EU
  11. Primary

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    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

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