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Quad-coils

Discussion in 'Pickups & Electronics [BG]' started by AlexK, Sep 23, 2001.


  1. AlexK

    AlexK

    Apr 10, 2001
    I'm having Dave Pushic build me a new custom bass, and I've got all the specs down except for the coil selections on the Bart quad coils I'm getting. I'm not good with electronics, so I came to ask you smart, experienced bass players for help. Dave e-mailed me the options I have for the coil selections:

    1: P-Bass (treble coil up), Full Humbucking, reverse P-Bass (treble coil
    down)

    2: Upper Coils , series Humbucking; Lower coils

    3: Series Humbucking, Lower Coils

    4: series humbucking, upper coils

    5 : parallel Humbucking, upper coils, series humbucking

    6: parallel humbucking, lower coils, series humbucking

    7: Parallel humbucking, series humbucking

    What do these mean? Any help would be greatly appreciated.
     
  2. Yep, definitely a job for the supermen over in Pickups!
     
  3. I too am in the process of finalizing my specs with dave pushic, and I emailed him about the quad coil selection switches. I guess I know what will be in the reply.

    somebody who knows what this stuff means, HELP!!!
     
  4. Luis Fabara

    Luis Fabara

    Aug 13, 2000
    Ecuador (South America)
    Audio Pro - Ecuador
    Hope that helps,
    My suggestion would be to use a Series - Parallel, Upperorlower coils.
    That gives you a good range of tones. All of this depends on pickup position again.

    Some manufacturers use resistors to make the output of the various coil selections similar, to reduce the differences. Ask David if he could do that so the volume differences are not as siginificative.
     
  5. geshel

    geshel

    Oct 2, 2001
    Seattle
    Louis addressed the sound, I'll cover what's going on inside the pickups, if anyone cares. :)

    So, some assumptions:

    1. Each item listed are the possible options for each pickup?

    2. "Upper" means "towards the neck" and "lower" means "towards the bridge"? That would be my normal inclination, although normal P-bass has the treble coil near the bridge. . .hmm

    If these are true, then each item listed corresponds to a 3-way (2-way for some) switch for each pickup.

    The four coils in each pickup are arranged like so:

    || ||
    || ||
    -----
    || ||
    || ||

    or

    1 2
    1 2
    ----
    3 4
    3 4

    I picked the numbers arbitrarily. The lower strings are picked up by coils 1 and 2, the higher ones by 3 and 4.

    If you're looking at the bass as it hangs on somebody else, here's how I would interpret the options you listed (with each switch setting separated by ';')

    1. coils 2 and 3 in series; all four coils in series; coils 1 and 4 in series

    2. coils 2 and 4 in series; all four in series; coils 1 and 3 in series

    3, 4, like Louis said

    5. possibly all four in parallel, but probably (1 and 2 in parallel) in series with (3 and 4 in parallel); coils 2 and 4 in series; all four in series

    6. replace the middle of #5 with "coils 1 and 3 in series"

    7. All four in series; beginning of #5

    Some general rules of thumb:

    - all of the above configurations will be hum-canceling
    - putting two coils that pass under the same strings in series will increase the output for those strings (and affect the sound)
    - two coils under a string in parallel have the same output level as a single coil (but different sound)
    - two coils under different strings (ie 1 and 3) in series does not increase the output, but it affects the sound

    As for the sound, I recently rewired my bass (has Bart quads) to get two new options. Here's my impression of the following (bear in mind position and bass itself have a lot to do with this, so just focus on the differences)

    1. Neck coil, series humbucking: round, not terribly fat. Good (if polite) pick tone. I use this, with chorus and overdrive and a pick, for Peter Hook stuff. Or, with more overdrive and fingers, John Wetton King Crimson.

    2. Bridge coil, series humbucking: barky, thick. Don't use so often, would more on a fretless. Sometimes used when tapping to cop Trey Gunn's sound a bit :)

    3. Both pickups (series humbucking) on: hi-fi-ish, a fairly even tone. Used to use this the most, with the blend a bit towards the neck. With overdrive and fingers, was using for Rush stuff.

    4. Neck P-bass, bridge coils 2+4 (all wired in SERIES, this is the funky part - for you the two pickups would be in parallel, sound a little different): brighter "neck" pickup sound, more aggressive. I use this for Rush and Tool now.

    5. Neck reverse-P, bridge coils 1+3 (again, in series): like #4 but more focused on the low strings, but more open on the high strings. High strings have more of a hollow-midrange J-bass slap tone. Can still be pretty aggressive. Use for some Tool songs.

    Anyway, hope that helps. :)
     
  6. thanks for the info guys, even if some of it went right over my head :confused:

    dave emailed me and said he likes the #1 config. for the neck pup. and the #6 config. for the bridge pup. I guess I'll go with that.

    what do you guys think about that, would that give me some good options?
     
  7. Luis Fabara

    Luis Fabara

    Aug 13, 2000
    Ecuador (South America)
    Audio Pro - Ecuador
    I agree..
    That will give you a lot of tones combinations...

    Just think:
    You can have a PJ sound easily.

    And then go to full Series Humbucking on both.

    Or Single coil at bridge + Parallel at neck.

    I think its a very nice combination.

    Go for it.