Ins't a 5 string p precision problematic

Discussion in 'Pickups & Electronics [BG]' started by darwin-bass, Jul 13, 2013.

  1. darwin-bass

    darwin-bass Supporting Member

    Mar 29, 2013
    Salem OR
    The P pickup is inherently a symmertrical thing. Two equal halves, equal windings and magnets. They cancel noise and each string is sensed by only 1 of the two pickup halves.

    But with a 5 string bass I'd think we have a problem. Either the pickups need to be asymmetrical with one half bigger than the other (what does this do to hum cancelling?) or we end up with the A string being sensed by both of the halves.

    Are these really issues or am I making it up?

    - Keith -
  2. darwin-bass

    darwin-bass Supporting Member

    Mar 29, 2013
    Salem OR
    Ins't? Really? I meant "Isn't".
  3. Smooth_bass88

    Smooth_bass88 vaxx!

    Oct 31, 2006
    Western Hemisphere
    Go to your local Fender dealer and play an American Standard P Bass and see for yourself. Check this out:

  4. smeet

    smeet Gold Supporting Member

    Nov 27, 2006
    Woodland Hills, CA
    Not a problem, although the asymmetrical pickup may look a bit weird.
    Theoretically, the hum canceling may not be perfect, but I don't notice it.
    I'd have to say the 5 string P (or PJ) is my new favorite configuration.
    ShirazBop likes this.
  5. khutch

    khutch Praise Harp

    Aug 20, 2011
    suburban Chicago
    I have a Standard Jazz V which came with split coil Barts that some previous owner had installed. Those pickups are asymmetric too: one "half" senses two strings, the other three. Yet it works quite well. I don't know what tricks you have to pull to make that work, only that they do indeed work. A P style pickup should work just as well.

  6. bassbenj


    Aug 11, 2009
    Yup, I put a real Fender P-bass 5er pickup in my Squire P/J 5er and they are 3 and 2. I was worried about imperfect cancellation but it seems to be no problem I do hear a tiny bit of hum leaking through but it's pretty minor. The DiMarzio bridge pickup on it is dual coils that are different sizes too and it has no hum pickup.

    So Yeah, you'd think it wouldn't cancel properly but as Smeet says, if there is any imbalance it's so minor you can't notice it. I have no idea if there is some pickup maker trick that makes it work, but it does work!
  7. bigjames

    bigjames Player of Smooth Lines

    I have a Sadowsky PJ 5 string and it is hum-free. Not sure how it all works, but is sounds fantastic.
  8. iiipopes

    iiipopes Supporting Member

    May 4, 2009
    I do not like a P-5 because for me the BEA segment is in the wrong position to get the optimum balance of fundamental and overtones for the B string to speak clearly enough, and the B string tuner is too close to the nut and causes the B string to bind around the tuning post, making tuning more difficult and risking breakage to the string.
  9. Lo-E


    Dec 19, 2009
    Brooklyn, NY
    I could be wrong here, but I believe that the number of turns of wire is what the hum-cancelling relies upon, so the number of pole pieces has little or no effect on hum. As long as both halves of the pickup have the same number of turns, the hum-cancelling should work just fine.

    Perhaps someone more versed in p'up construction can confirm or debunk this....
  10. Bassamatic

    Bassamatic keepin' the beat since the 60's

    Lo-E is correct, Also - the difference between the 2 halves would be hard to perceive even if they were not wound exactly the same.

    The single-coil hum-cancelling design of the P Pickup with 1/2 having reversed polarity magnets is, to me, truly ingenious.
  11. bassbenj


    Aug 11, 2009
    Sort of but not exactly true. If you have pickups (like Barts) where both coils are the same size then what you say is true. The amount of hum pickup has to do with the number of turns and the area of the coil. The number of poles you put in the coils to pickup strings doesn't matter.

    But the Fender 5er pickup coils are different sizes. That means with the same number of turns they pick up different amounts of hum. Now you can adjust the number of turns to fewer on the larger coil to balance the hum pickup. But if you do that, then you also lower the signal from the strings and the two halves are no longer balanced. Hence the problem we are discussing. There must be some sort of trick (since my P-bass 5er with two difference size coils does cancel hum) but I don't know what it is.
  12. two fingers

    two fingers Opinionated blowhard. But not mad about it. Inactive

    Feb 7, 2005
    Eastern NC USA
    As with any coil, sure the overall area plays a part. But, I think the number of turns has more to do with it than anything. So much so that the difference in area of the coils (especially in a case such as this where the coils are so relatively small and similar in size) would not bring about much in the way of "undoing" the hum canceling effect of the original design.
  13. darwin-bass

    darwin-bass Supporting Member

    Mar 29, 2013
    Salem OR
    In the case of the new Carvin P bass, the pickup is symmetrical and the middle string (A string) is picked up by both halves of the split humbucker.

    I'm thinking this would offer optimal hum bucking but the A string would be stronger.

    The reason for the questions is that I'm considering changing my 5-string J bass to a 5-string PJ.
  14. uOpt


    Jul 21, 2008
    Boston, MA, USA
    It's still about the same length of pickup coil wire (wound to same D/C resistance for both coils), so the hum canceling works OK. It's not perfect because outer layers shield inner layers so it's uneven after all.

    Complete hum cancellation really isn't necessary. If it was we would actually shield our guitars :) The output of the passive pickup is enough to get you a good enough signal/noise ratio even while having incomplete hum cancellation and only partial shielding.

    Or think about it the other way: if this little difference was really bad, an actual single coil like in a Jazz bass with no cancellation whatsoever would be completely unusable.
  15. Ric5

    Ric5 Supporting Member

    Jan 29, 2008
    I like 5, 8, 10, and 12 string basses
  16. darwin-bass

    darwin-bass Supporting Member

    Mar 29, 2013
    Salem OR
    OK this illustrates one of my questions. The A string will be picked up by both halves of the pickup.

    Since the string is "falling off the edge" of each pickup half, does that mean that it takes both halves to give full strength (i.e. it is 3dB weak in each half)
  17. Hopkins

    Hopkins Supporting Member Commercial User

    Nov 17, 2010
    Houston Tx
    Owner/Builder @Hopkins Guitars
    The the shorter coil will have more turns than the longer one. The number of pole pieces wont matter. As long as the pickups are turned to close to the same resistance, the pickup will work just like a 4 string P pickup.
  18. Batmensch


    Jul 4, 2010
    Media, PA.
    That's not a proper 5 string pickup. that's for a four string, a five string pickup wouldn't have that problem.
  19. Hopkins

    Hopkins Supporting Member Commercial User

    Nov 17, 2010
    Houston Tx
    Owner/Builder @Hopkins Guitars
    You are thinking about it as each coil being one individual pickup. Since they are wired in series, the end of one winding ties into the beginning of the other winding, so it is basically one coil.
  20. Ric5

    Ric5 Supporting Member

    Jan 29, 2008
    I like 5, 8, 10, and 12 string basses
    It works just fine ... don't think about it so much ... just play it.