1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  
    TalkBass.com has been uniting the low end since 1998.  Join us! :)

Schaller JBX/DiMarzio Model J with missing magnets

Discussion in 'Pickups & Electronics [BG]' started by SpasticTastic, Dec 15, 2016.

  1. SpasticTastic


    Dec 22, 2012
    So I purchased myself a 2nd-hand Schaller JBX (supposedly a clone of the DiMarzio Model J) on eBay for a good price. The main problem is the pickup does not have the magnets anymore.


    So, I'd like to know how one would go to finding the parts required to fix it? What size magnets would I need? What kind of spacers/keepers am I looking for?

    Thank you. :)
  2. Axstar


    Jul 8, 2016
    East of Eden.
    I had a set of JBX pickups for a while, and if I still had them I would ship you the spacers as I ended up cannibalizing the pickups. I imagine the spacers are bespoke items and will be very hard to find. I also imagine that a Dimarzio part wouldn't do the job, as Dimarzio will use an imperial measurement whereas Schaller will be metric.

    If you are never going to adjust the poles them you could probably just epoxy some thin ceramic bar magnets to the back of the pickup, remembering to use four; one pair per pickup half.

    I hope you got a good price for that pickup, as I just bought a NOS Schaller PBX from a seller that also has a black JBX for sale here: Schaller Jazz-Bass PU JBX Nr. 246 bridge schwarz von 1986 | eBay

    I hope you paid substantially less than that!
  3. SpasticTastic


    Dec 22, 2012
    I didn't pay that much, luckily. :D

    So, is the metal spacer/keeper bar unnecessary? All I need are a few magnets? If so that isn't TOO bad. Just need to know the proper size for each magnet.
  4. Axstar


    Jul 8, 2016
    East of Eden.
    The metal spacer/keeper is handy, as it allows the pole-pieces to rotate. I had an old Schaller pickup with adjustable poles, but only a single coil. When you rotated the poles to adjust them they simply detached chunks of epoxy off the back of the pickup and dislodged the magnets, as there was no keeper bar in place.

    Simply measure the distance between the four poles of one half of your pickup, and aim for magnets a little longer than that.
  5. SpasticTastic


    Dec 22, 2012
    Alright. I'll try that. I just assumed the steel spacer was also there for magnetic reasons.

    So, I just take the 4 magnets and glue/epoxy them on like here?


    But instead of having the spacer, will the magnets be directly touching the pole pieces?
  6. SpasticTastic


    Dec 22, 2012
    Oh, I have another question... The polarity.

    Is there a certain way the polarity has to be?

    I apologize, I'm not smart with pickups and magnets at all. :(
  7. i purchased from this seller (nice person) a Schaller P-J set. Great pickups, in my opinion better than the DiMarzio.
    You can wire the p-up in series, parallel, in phase and out of phase.
    Usually the series configuration (brown& white soldered together, yellow hot, green= ground) means more output and "fatter" tone.
    Parallel (Yellow and white soldered together as hot, brown and green soldered together as ground) means a thinner, clear tone wit more highs and less output. A dpdt switch allows to choose both sounds.
    Out of phase... WEIRD, quacky tone, useless.
  8. wcriley


    Apr 5, 2010
    Western PA
    Assuming you mean magnetic polarity (and that the pickup is humbucking), the side of the magnets facing the poles need to be "like-facing", but each of the two sets of poles needs to need to have reversed magnetic polarity. North touching one set, South touching the other.
    If you mean electrical polarity between the coils, it depends on how the coils were wound. If you leave the wires as they are, you should be good to go.

    As for the keeper: It was there to have something for the pole pieces to thread into and to keep the like-facing magnets from trying to push away from each other. Without it, you might have trouble keeping the magnets in place until the glue sets. (I don't have any experience with like-facing magnets in pickups, so I can't be certain of this.)

    One thing I'm fairly sure of is that the pickup will sound different without the keeper. But it will likely sound different anyway because the replacements will be at least a little different in composition and strength. And if the magnets are the same size as the originals, the return path of the magnetic circuit will move inward a small amount, which could also affect the sound.

    It would be interesting to experiment with 2 sets of magnets and compare the sound; one the same size as the originals, the other slightly wider to take up the space vacated by the keeper.

Share This Page