Hum cancel for P90's

[big_teee]

reviving an old thread....If they are Gibson P90s, you most likely do not have to re-wire the leads to reverse the phase. I just did this mod, and flipped the coil over, and reversed the magnets, and voila. No need to re-wire. But, this is probably only the case for actual Gibson p90s.
-Erin

If both pickups are wound the same direction, and one has magnets with north polarity, and the other has south polarity.
Then they may be hum canceling, but they are for sure out of phase.
It wouldn't matter what brand they are.
To put them back in phase, would require reversing the wires at the pickup.
Later,
Terry

[lexluthier72]

Terry,
This is true 99% of the time. With the gibson pickups I just did, it was not the case. Both magnets were the same polarity when I started. I did originally change the wiring, but found that when I did that, it was out of phase. Changed the wiring back to stock, and voila....hum cancelling. I guess it pays to merely flip the coil and magnet, and test before you mess with re-wiring the pickup.
-E.

I wasnt about to un-tape it to see which direction the bridge pickup was wound!

[big_teee]

Very interesting.
Don't know ton's about gibson P-90s.
I presume that they use the exposed shielded push back wire?
On Strat type coils I wind them all the same direction, but I make one north and flip the wiring.
On rewinds, I actually wind the different pickups different directions, and always ground the start wire.
On this deal I Will take your word for it, and if you like it, I like it!
Later,
Terry

[lexluthier72]

I was very suprised that I did not need to "fix" the phase by rewiring the coil. Yes they do use braided "push back" wire. This mod rocks for anyone not liking the 60 cycle hum. With a proper overdrive you can dial some of the lost treble back in, and you dont lose the oomph of the p90 sound!
-E.

[jrfrond]

About dummy coil systems: unless it is an active system that isolates the dummy coil from the pickup and uses a balanced preamp system e.g Alembic, the added inductance of the coil in parallel with the pickup will change the "Q" of the circuit, as well as the resonant frequency, and it will no longer sound like a P90, as Dave said. Music Man has an active system with P90's as well in the Axis, but I've actually removed them in several guitars and retrofitted them with either new P90's or P90-sized humbuckers, which worked out much better in all cases.

[Mark Hammer]

I have this theory that the tone of electric solid-bodies will be partly determined by whether the bridge is situated closer to the waist (narrowest point) or to the hips (widest point) of the guitar (of course where that is on a Flying V is another story, but we'll ignore that for the moment). One of the consequences of joining the neck to the body higher up, and having more frets on the neck (24, vs 22 or 20) is that the bridge is somewhat obliged to be much closer to the waist. But another consequence, amply illustrated by the SG and the recent Epiphone Wilshire re-issue (both of which have longer necks, joined higher up), is that the need to reserve some body space for a sturdy neck tenon, results in less space available for the pickups. This, in turn reduces the distance between the neck and bridge pickups, diminishing the tonal contrast between them, making any out-of-phase tones less useful (because of big volume drop), and making N+B sounds much less distinctive.

To my mind, there is not so much a "right" and "wrong" location for a pickup, as much as there are more, and less, useful positions for them. Having a nice physical spread between neck and bridge pickups (partly achieved by tucking the neck pickup closer to the end of the fretboard) helps to accentuate the tonal difference between them, whether playing open or fretted strings, and makes multiple-pickup combinations more useful. And of course, having pickups which are, in and of themselves, tonally distinctive, enhances that even more. It's one of the many reasons why Teles in their original formulation are still "enough" for a great many players: there is a huge contrast between the three pickup-selector settings. Indeed, with their more focussed aperture, it's part of what makes single-coil pickups so desirable: distances between their apertures are easier to achieve, even within confined spaces.

[Sweetfinger]

I was very suprised that I did not need to "fix" the phase by rewiring the coil.

When you flipped the coil over, you were essentially "rewiring" the coil. If you can physically flip a coil, great, but a lot of the time that is not possible, so you have to flip the leads.

[mac1amps]

Another Lover of P-90's......I own a few guitars w/ P-90's ('56 style Gold-Top; [Gibson] Blues-Hawk; and a Tele w/ P-90 in "neck" position)........anyway, I just wanted to add, in reference to the "dummy" coil issue, that I REALLY had "high hopes" for the sound of the Blues Hawk, but it doesn't "deliver" the true P-90 sound (yes, I know, since there aren't screw terminals to adjust the pole pieces like on traditional P-90's, they call them "Blues 90's", but they're still essentially P-90's). I've been meaning to disconnect the "dummy", to see if it makes any difference......I suspect it will (I don't mind a little 60 cycle IF I'm getting the sound I like......you don't hear the noise while the band's playing anyway).

[lexluthier72]

The above mod, only affects the mid position. The best of both worlds.

[Earl Norton]

use a noise gate!!!