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Quad Coil Pickup Idea

Discussion in 'Pickups & Electronics [BG]' started by FunkMetalBass, Oct 20, 2010.


  1. FunkMetalBass

    FunkMetalBass

    Aug 5, 2005
    Phoenix, Arizona 85029
    Endorsing Artist: J.C. Basses
    I'm a bit n00by in the area of pickups and how the diagrams are designed, but I remember being a bit disappointed when I found out that Nordstrad quad-coil pickups could not be switched in a manner of a P or a reverse P due to the magnets' polarity (at least, not while retaining the pickups original ability to be perfectly hum-cancelling in either of the S/H/S configurations).

    I got to thinking about it last night, and if it were wired up like a Wal pickup with one coil per magnet and each pole's polarity is opposite the adjacent pole, would it be possible to switch between a S/H/S/P/reverse-P configuration?
     
    Bassitudes likes this.
  2. jworrellbass

    jworrellbass Commercial User

    May 17, 2009
    Colorado Springs CO
    Owner, builder: jworrellbass
    I could make something like that, it would be 2 split coils J's with 8 wires and 1 neo bar magnet in between the 2 coils.
    Hooking up all those wires is a different story..;)
    Send me a PM if your interested.

    John
     
    Bassitudes likes this.
  3. Stealth

    Stealth

    Feb 5, 2008
    Zagreb, Croatia
    Props go to tubby.twins, the man who built this thing for me long ago when I wanted to wind a quad-coil for my six-string J/MM. Still haven't done it, but the schematic stands proud.

    http://www.gerb.ws/talkbass/pickups/stealth/hybrid5_quadcoil/try002.pdf

    You'll need a 4-pole, 6-position rotary.

    Edit: Not sure about the hum-canceling property of it all. My assumption is, if you went with the left quarters being wound in the same direction and polarity, and the right quarters being wound in the other direction with the opposite polarity, all positions would hum-cancel - front-J, P, MM, reverse-P, rear-J - and you can even make them in-series or in-parallel with a few strategically placed shorting wires.
     
  4. tubby.twins

    tubby.twins Amateur Pickup Reviewer Gold Supporting Member

    Apr 15, 2009
    Oregon
    Yeah, that was something that didn't occur to me until recently. The pickup would have to have both coils covering the same set of strings to have the same direction and polarity.
     
  5. FunkMetalBass

    FunkMetalBass

    Aug 5, 2005
    Phoenix, Arizona 85029
    Endorsing Artist: J.C. Basses
    I hadn't considered doing it all with a rotary switch. I was going to do it with a sequence of three DPDT (on-on-on) switches mounted to a PCB like so:
    (for reference, N = neck, B = bridge, 1 = coil with EA strings, 2 = coil with DG strings)

    switch 1: N1; N1 & N2 (parallel), N2
    switch 2: B1; B1 & B2 (parallel), B2
    switch 3: Switch 1; Switch 1 & 2 (parallel), Switch 2

    He just sent me a diagram, and it looks like the rotary diagram posted wont work, so I might be forced to use my idea.
     
  6. Darkstrike

    Darkstrike Return Of The King!

    Sep 14, 2007
    Brtolini Quad's will do P/Reverse P setups.
     
  7. FunkMetalBass

    FunkMetalBass

    Aug 5, 2005
    Phoenix, Arizona 85029
    Endorsing Artist: J.C. Basses
    Not a Bartolini fan. But I appreciate the feedback, as I didn't think that any of the mass-produced quad-coils did.
     
  8. SGD Lutherie

    SGD Lutherie Inactive Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    I'm currently doing a custom set of pickup for someone like this. Each pickup will have a 5 way rotary switch. They are in MM cases with exposed alnico poles, but small dual poles like a Jazz or P bass pickup.

    I'm not so sure what use P or reverse P would be. I think the two will sound very similar. But I'm wiring up the switch that way.

    I'm also going to setup the Wal clone so it can be switched this way.
     
  9. Darkstrike

    Darkstrike Return Of The King!

    Sep 14, 2007
    I suppose something like it could be rigged up by any two split coil J pickups with 4 conductors, butt 'em up side by side, and two or three inventivly wired mini toggles, you could have literally tonnes of tone options.
     
  10. FunkMetalBass

    FunkMetalBass

    Aug 5, 2005
    Phoenix, Arizona 85029
    Endorsing Artist: J.C. Basses
    I agree that the two will probably sound very similar, but I'm a man of options, and since this will be on an MM/P bass, it seems that leaving both open for experimentation will be the best way to go.
     
  11. SGD Lutherie

    SGD Lutherie Inactive Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    It's easy enough to do. :D
     
  12. FunkMetalBass

    FunkMetalBass

    Aug 5, 2005
    Phoenix, Arizona 85029
    Endorsing Artist: J.C. Basses
    Wouldn't one have to worry about potential phase issues when separating out pickup coils like that?
     
  13. SGD Lutherie

    SGD Lutherie Inactive Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    Not if you have the coils laid out the right way. You have to think of them as two humbuckers neck to each other.
     
  14. Stealth

    Stealth

    Feb 5, 2008
    Zagreb, Croatia
    Indeed.

    To give a visual example:

    MMbucker.png

    Suppose the coils are named N(ea), N(dg), B(ea) and B(dg) (I think tubby.twins named them as such on the PDF above, too). Suppose the coils are wound and magnetically polarized like this:

    N(ea), B(ea): clockwise, N-up
    N(dg), B(dg): counter-clockwise, S-up.

    Thus the combinations are as follows:

    N-jazz: N(ea)+N(dg)
    prec: N(ea)+B(dg)
    MM: N(ea)N(dg) + B(ea)B(dg)
    R-prec: B(ea)+N(dg)
    B-jazz: B(ea)+B(dg)

    So if you look at the upper table, all combinations are RW-RP. No phase issues, as far as I can tell.

    Surgeon luthier's warning: reverse-wound/reverse-polarity does not necessarily imply the coils are actually wound in differing directions.
     
    MovinTarget likes this.
  15. SGD Lutherie

    SGD Lutherie Inactive Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    Exactly.

    +1
     
  16. AltGrendel

    AltGrendel Squire Jag SS fan.

    May 21, 2009
    Mid-Atlantic USA.
    Noob question:

    Won't the inactive coils affect the tone anyway?
     
  17. FunkMetalBass

    FunkMetalBass

    Aug 5, 2005
    Phoenix, Arizona 85029
    Endorsing Artist: J.C. Basses
    That's what I figured, I just wanted to be sure that would cover all the bas(s)es.

    Thanks, homie!
     
  18. SGD Lutherie

    SGD Lutherie Inactive Commercial User

    Aug 21, 2008
    Bloomfield, NJ
    Owner, SGD Music Products
    No.
     
  19. MovinTarget

    MovinTarget Supporting Member

    Jan 30, 2018
    Maryland, USA

    Sorry to Necro this thread, but apart from possibly the Sims Super Quad, are there any other such manufacturers of this design?
     
  20. ctmullins

    ctmullins fueled by beer and coconut Gold Supporting Member

    Apr 18, 2008
    MS Gulf Coast
    I'm highly opinionated and extremely self-assured
    Yep. Delano and Bartolini make ‘em.
     

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