Should Strat middle pickup have reversed magnets?

Discussion in 'Luthier's Guitar & Bass Technical Discussion' started by donnyjaguar, Feb 28, 2006.


  1. donnyjaguar

    donnyjaguar Member

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    On my Fender Strat I've noticed that when you select the in-between positions on the selector that it doesn't appear to reduce the ambient noise level via the humbucking action. This is the opposite of what my old Strat did (which I never should've sold, but that another story). I took out my trusty mini magnet and determined that the polarity of all 3 pickup magnets' pole pieces is the same. I'm guessing the middle coil is reverse-wound and responsible for the out-of-phase tone. And it is definitely an out-of-phase Strat tone.

    My question is whether the middle *should* be wound the same way but with reverse magnets?

    DJ
     
  2. Jim Collins

    Jim Collins Member

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    Some Strat models feature a RW/RP (reverse wound/reverse polarity) middle pickup, but not all models have it. Vintage reissue models do not.

    The Strat inbetween positions are not supposed to be out of phase. All three pickups are supposed to be in phase. If your inbetween positions are truly out of phase, the middle pickup is just connected backwards.
     
  3. John Phillips

    John Phillips Member

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    If all three pickups have the same polarity, and hum is not cancelled in the 2 and 4 positions, it's wired correctly.

    In order to cancel hum the middle pickup must be reverse polarity and reverse connected (called reverse-wound but it isn't really). This puts the pickups in phase - which is what the normal Strat in-between sounds are. Why they are commonly called 'out of phase' I don't know.

    If you want to see what out-of-phase really sounds like, swap the wires on the middle pickup :).

    Fender introduced RWRP middle pickups only in 1985, on the US Standard, BTW - all Strats made before this, and reissues of them, have same-polarity pickups and no hum cancelling. Why this should be, when the humble Duo-Sonic got RWRP pickups in 1956, I do not know. But given that they only fitted the Strat with a 5-way switch in 1977, presumably they never intended the pickups to be used together... so there was no point in making them hum-cancelling ;).
     
  4. donnyjaguar

    donnyjaguar Member

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    Thanks Jim 'n' John,

    You've shattered my understanding of Strat wiring! :D

    Three questions:

    In your opinion, Is it worth replacing the middle pickup with one that is RWRP? The noise on mine isn't bad, but its there.

    If I wired my middle pickup the opposite way, what would it sound like?

    Can I push the pole pieces out and re-insert the opposite way?

    DJ
     
  5. Jim Collins

    Jim Collins Member

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    If you wired the middle pickup in reverse, the two, inbetween sounds would be thin and nasally, with a significant drop in volume.

    It is possible to push out the magnets and push them back in, but the chances are very good that you'll destroy the pickup. The wire is wrapped directly around the pole pieces. By pushing them out, and then back in, you stand an excellent chance of breaking the wire. Since the break would be on the inside of the coil, the pickup would have to be rewound in order to save it. (Unless the pickup is a vintage pickup, rewinding it isn't worth the cost. Of course, if it were a vintage pickup, you wouldn't really think of doing anything that would destroy it.)

    As far as replacing the middle pickup goes, it can be a bit more complicated than that. There is no industry standard as far as magnetic polarity goes. Even Fender changed polarity at least one point in the past. A pickup manufacturer builds according to his own standard, but his standard may not be the same as another maker's. A lot of Tele players replace the neck pickup with a Duncan, only to discover that the new neck pickup is out of phase with the stock bridge pickup. Just purchasing a RWRP pickup is no guarantee that it is RWRP with respect to your pickups.

    John -- at what point did Fender go to RWRP pickups in the Duo Sonic? I grew up playing a mid-50s Duo Sonic. (I sort of inherited it from my brother. After about 35 years, I gave it to his daughter, who expressed an interest in learning guitar.) My Duo Sonic was not hum cancelling in the middle position. I never verified whether the exact year of the guitar, but it was quite some time before rosewood fretboards were introduced.
     
  6. John Phillips

    John Phillips Member

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    If you only or mainly use the in-between positions and the hum does bother you, yes. Replacing the middle pickup with a RWRP one will cure it. It has very little (although I'm not convinced "no") effect on the tone. If you mostly use the individual pickups it's probably not worth it - although sometimes noise on stage can be so bad that it's worth having the option, even if you don't normally use that sound (I would probably put myself in this category, even though I don't really like and rarely use the in-betweens on a Strat).

    Very thin and clucky - like an exaggerated version of the normal in-phase tone - and about half the volume.

    If you have a vintage-construction pickup with fiberboard top and bottom plates - NO. You will destroy the pickup. The wire is wound directly onto the magnets, and even if you try to adjust their heights you will often break the innermost coil winding. Removing the polepieces and pushing them back in would make it a certainty.

    BUT if it's a modern US Standard/Series pickup with a plastic bobbin, yes you can. The magnets are in plastic tubes separated from the coil and there's no problem with doing this. Push all the magnets out, reinsert the other way, and connect the wires the other way round and you have a RWRP pickup.
     
  7. John Phillips

    John Phillips Member

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    I thought they all were right from the start ('56), but obviously not if yours wasn't. A friend of mine had a '61 - still the earlier type, although rosewood board by then - which as far as I remember was, and my '64 Duo-Sonic II definitely was. The Jazzmaster (introduced in '57) did definitely have them from the start, and the P-Bass got the split pickup in the same year, so it's possible that the earliest Duos didn't and only got it after the Jazzmaster. It would probably be more likely that a feature like this was introduced on the premier guitar in the line, rather than the second from bottom :).

    Fender really didn't seem to like to change things even to improve them - the Tele, which got the 'modern' switching enabling both pickups together in 1967 (I think) never got RWRP pickups.
     
  8. donnyjaguar

    donnyjaguar Member

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    Yes, its a late model Strat with the one-piece bobbin.
    This is very cool. I will attempt this operation upon my next string replacement. :RoCkIn

    I'm guessing that the reversed magnetic poles on the middle pickup also reduce the liklihood of that dreaded string warbling on Strats.

    DJ
     
  9. Jim Collins

    Jim Collins Member

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    It will have no effect. The magnets will attract the strings, no matter which way the magnets are pointing. The warbling, or Stratitis, as it is often called, is a result of the pickups being too high -- too close to the strings. That has a dampening effect on the strings. If you are experiencing this, try lowering the pickups.
     
  10. donnyjaguar

    donnyjaguar Member

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    Just a quick update to let the group know I successfully removed, rotated and re-installed the magnets in my middle pickup. Reversed the pickup wiring and now I have humbucking action in the 2 & 4 switch position. This is a worthwhile modification in my opinion.

    DJ
     

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