P90 PU's and noise - newb question

[pinkjimiphoton]

can confirm. wherever you can fit it.

[Mark Hammer]

That'snot to say any location will work as well as any other.  But even in locations where you might think "Well THAT's not going to work", you still get some hum reduction.  Not complete cancellation, but some reduction is better than none.

[pinkjimiphoton]

yeah, true, BUT with azimuth you can eek as much out of it as possible. different orientations will "phase" it in different ways. its never gonna be perfect, but even 6db less noise is a lot.

last time i did this was on a jaguar, i ended up using an old teisco single coil, just the coil part itself, in the lower control cavity. i literally wired it across the volume control so it was always in circuit... which worked out in some interesting ways. a phase switch got added to the neck so i could reverse it, cuz most of the time i'm on my bridge pickup.... hey man, its my style... so i played with the dummy coil to get the best effect i could outta it. but that wasn't necessarily right for the neck... so having a phase switch is cool, cuz it gives more options.

i got a red special recently. the bourns p'ups are kinda similar to p90's tonally. they are completely shielded, and sound great. they CAN hum, but its fairly minimal.... and you can exploit the phase switching.
if ya think about it, by choosing the phasing of your pickups, you can make the ultimate amp's speaker either suck OR blow.... so if you're say, having two pups on in a humbucking situation, but your sustain ain't happening, if ya reverse the polarity on BOTH then suddenly you'll get the additive feedback instead of subtractive at almost the same kind of tone.

the brian may wiring thing is a thing of beauty. with p90's and a good shielding job, and maybe a dummy coil, you could probably do some serious damage in interesting ways

[stallik]

Just to close this one off and report the solution. I removed all the hardware from this guitar in order to apply the finish. English polish - just Like French polish but not as well applied Rather than fill the grain with pumice, I decided to use a gold grain enhancer on the front and sides. This gives an extra glow to the wood but still leaves a texture in the wood which is clearly visible within the high gloss finish. Still looks nice though.

Anyhow, I used conductive paint under the control cavity and both PU's. The control cavity is earthed via the pots but I screwed an earth wire into the paint under the PU's. That stopped the noise. Almost. I'm using a wiring scheme with a 5 pos blade switch. First 3 positions are standard telecaster switching, 4&5 reverses the polarity of the neck PU. I have a short between the earth on that PU and my cavity earth so, when selecting those positions I get (almost) silence. Disconnecting the neck cavity earth sorts the sound but of course the noise returns on those 2 selections.

Removing the strings to take out the neck PU will have to wait till next week but at least I now have a solution. And a shiny new guitar!

[Digital Larry]

your body poots forth

Do it again!  Do it again! <<<SNOOOORRKKKKK>>>

[soggybag]

Can't you get some noise canceling by using both pickups with one being reverse wound? I thought this was a classic arrangement used by Gibson on some guitars.

I wonder if you could use three P90s with a reverse wound middle pick always on.

[Rob Strand]

Can't you get some noise canceling by using both pickups with one being reverse wound? I thought this was a classic arrangement used by Gibson on some guitars.

I wonder if you could use three P90s with a reverse wound middle pick always on.

The idea works when you have two single-coil pickups with out of phase coils (for external fields).   It only works when the volumes are both full (in practice one is a little off)   The P-bass is an interesting one because it is two pickups that are always on and always humbucks.

If you use a third coil as a dummy then you need to do some switching work to make it happen:   
- When you have the two working pickups on you need the dummy switched out. 
   The two working pickups provide the cancellation (but only when both volumes are full).
   That requires the two working pickups to be magnetically out of phase.
- When you run the pickups individually, the nature state of the dummy coil will be in phase
   with one pickup and out of phase with the other.
   So you need to flip the phase of the dummy with a switch for the out of phase pickup.