Modifying P90 pickups for bass.

Discussion in 'Pickups & Electronics [BG]' started by Axstar, Oct 10, 2016.

  1. Axstar

    Axstar Inactive

    Jul 8, 2016
    Scotland.
    So.... I have an unusual idea.

    I have a couple of basses with pickups that fit the exact footprint of a standard guitar humbucker. Coincidentally one is my namesake, the Axstar! In both cases the pickups seem to be too hot. The Axstar is the worst offender. I tend to have to roll back the gain until the bass is set at a whimper, else the bass is rudely clipping everything. I find this ruins my chances of playing with any real sense of dynamics, as it is either clipping or quiet and thin sounding.

    The humbucker dimensions limit my options for replacements really, as there are only a small handful of bass pickups designed to fit these dimensions. I've considered buying some overwound humbuckers with blades and wiring them with the coils in parallel. The common challenge seems to be finding pickups with a wide enough sensing area to capture the full excursion of the strings; around 57 mm or so. Oddly enough the Axstar's pickups have 12 poles; the bass is equipped with two Gotoh-branded guitar humbuckers under 'Axstar' branded covers.

    I've noticed several retailers offer up budget P90 pickups that are patterned on a humbucker footprint. Having owned some of these in the past for guitar duties I understand the basic construction of these. Generally speaking they have a central ferrous core that the poles screw into, a squat fat single coil and two chunky magnets on the back of the coil. Is there some way I can modify a set of these pickups for four pole-pieces, or simply invert the pole-pieces and keep them flat against the top of the ferrous core? I would simply replace the plastic pickup cover insert (with six holes) with an identical plastic sheet with no holes, and adjust the pickups a little closer to the strings to get a stronger signal.

    Is this a complete waste of time? I don't wish to spend a lot of money as this is sheer experimentation with no set goal.
     
  2. honeyiscool

    honeyiscool

    Jan 28, 2011
    San Diego, CA
    Why don't you try running your humbuckers in parallel as a quick fix?
     
  3. Axstar

    Axstar Inactive

    Jul 8, 2016
    Scotland.
    That would require modifying them to a four-wire setup.
     
  4. honeyiscool

    honeyiscool

    Jan 28, 2011
    San Diego, CA
    I haven't found that to be all that difficult in the past. It usually involves taking the coils off, unwrapping some tape, and resoldering a 4-wire lead.
     
  5. iiipopes

    iiipopes Supporting Member

    May 4, 2009
    1) What is wrong with the volume knob on the bass? Does it have to be dimed?
    2) Have you lowered the pickups a turn or two away from the strings?
     
  6. Sunset Shalom

    Sunset Shalom

    May 9, 2016
    Honestly I would be tempted to just see how they work as they are. Here is a regular P90 in a bass and it sounds killer:



    And they didn't even bother using one that fit + its a 5 string! I bet they would handle 4 perfect and maybe even a 6er...
     
  7. Steve Dallman

    Steve Dallman Supporting Member

    My first bass was a short scale, 1962 Carvin. Carvin used the same pickups in their guitars and basses. They were from Hofner (as were the necks) and looked much like P90's.

    For the basses, they removed the 2nd and 4th polepieces, and put stiff black cardboard plugs in the polepiece holes. They worked just fine.
     
    Axstar and Sunset Shalom like this.