2 p90's to form a humbucker..?

Pickups, wiring schemes, switch techniques and onboard active electronics for guitars and basses
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DesertCruiser
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Post by DesertCruiser »

As the topic says, what do you think? I saw this other thread about using two SC's, and i thought it would be interesting to do the same thing with a couple of soapbars i've got laying around :hmmm: They're nothing fancy, got them from a friend who had switched them to HB's in a cheapish guitar, so its no big loss if they're getting screwed up. Think they've got pretty much the same imedance as well.
Guess i could sacrifice my old Epiphone SG and give it a surgery with the router in the name of science, i really like P90's!
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lolbou
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Post by lolbou »

If you put the coils in series, you'll also need to have the magnets being opposite to have humbucking. Maybe they already are if they are? Maybe not.

Reversing polarity is quite easy to to with cheap SCs (you just reverse the magnet at the base of the poles). I don't really know how difficult it would be to do it with standard SCs (possible winding damage?)...

Try and dismantle the P90 to reverse the magnets on one of the two pickups. Maybe it ain't that much work?

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Post by DesertCruiser »

Yeah i took the covers off today and the magnet pieces of the different pickups were repelling when i tried to put them together. But it was quite easy to take the baseplate off of one of them and flip the magnets around, just had to clean off some glue. Now they stick beautifully together :applause: Man this thing is going to look fat..
Now if i understand this subject right from what i read in the other thread i don't have to flip the bobbin over as well, i just have to make sure that the start of one PU goes to the finish of the other to achieve humbucking, right?
Tomorrow i'll make a new big baseplate that fits both PU's. Will put up some pics when that is done

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Post by lolbou »

DesertCruiser wrote:Now if i understand this subject right from what i read in the other thread i don't have to flip the bobbin over as well, i just have to make sure that the start of one PU goes to the finish of the other to achieve humbucking, right?
No. If both windings are identical, you have to do it like this:

OUTPUT (+) --> [winding 1 (+) --> winding 1 (-)] --> [winding 2 (-) --> winding 2 (+)] --> GND

This way the RF noise is cancelled, but the string sound is doubled.
DesertCruiser wrote:Now they stick beautifully together :applause: Man this thing is going to look fat..
You bet! Good job anyway!
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Post by DesertCruiser »

lolbou wrote:
DesertCruiser wrote:No. If both windings are identical, you have to do it like this:

OUTPUT (+) --> [winding 1 (+) --> winding 1 (-)] --> [winding 2 (-) --> winding 2 (+)] --> GND

This way the RF noise is cancelled, but the string sound is doubled.
Ah, yes, what was i thinking :) It's a bit confusing before you really get your head around it. Expressions like "opposite wound" can be a bit vauge for a beginner.
What you are saying makes a lot of sense now when i think about it.

Well, here is some pictures of the pickup, think im gonna call it The Phucker ;) , and the not so carefully routed SG.

The original PU disassembled:
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New baseplate made from 1mm aluminium: (have to make some sort of terminal here)
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Front view:
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The sacrificed guitar. May have slipped a bit there... ahum...well who cares
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Sorry for the bad quality, my camera isn't what it has been.

I have also made a plate with threaded holes that is going to sit behind the PU, attaching it to the guitar body.
Hoping to hear it soon!

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Post by DesertCruiser »

It's alive! Tried it yesterday and i'm not disappointed, this thing definitely has some potential, there's just some adjustment that has to be done.
Once i had got it in there and the strings were back on there was no turning back. Wired it up for standard series humbucking and plugged it in.
And it worked at first try, suprisingly!

The first thing that struck me was that there were no hum, which instinctively felt a bit weird. I mean it's after all p90's which to me is associated with some background noise.
The second thing i noticed was that this thing delivered some serious output swing, even too much for my Vox VT15. The clean "channels" (or what you are supposed to call the different amp simulations in a modelling amp) were distorting in an ugly kind of way with the guitar volume pot maxed. I have yet not measured how much voltage it is capable of putting out but will check that on the scope later.

The sound had a pronounced low mid and the treble felt a little damped. Great for clean melodies, gave a very warm, woody and almost compressed feeling. Tight low end. Had to roll back on the volume pot though to avoid clipping.

On the dirtier channels i got some great sustain and very little overall noise. Great for solos but for rhythm i could wish for some more bite and "wacka-wacka" when holding the fingers over the stings without completely pressing them down and strumming, know what i mean? Don't know the term.

Well anyway, because the treble was a little low for some playing styles i put a DPDT in there to allow for series/paralell switching. The paralell mode gave me the highs back and a more manageable output level. I think this works better for power chords ans clean chord strumming.


Here are the pictures of the wiring terminal at the back of the PU and the guitar with the PU mounted:
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(Why are the pictures so goddamn big? I tried to scale them down in photobucket but that seems to have worked with the guitar picture. Is there some way to scale them down when making a post?)

Haven't decided how i wanna wire this thing up quite yet, it would bee nice to have the option to use only the north or south coil separately as well. Is there some wiring scheme out there that allows for humbucking in series/paralell as well as south/north coil selection?

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Post by D-Day »

This is awesome! Thanks man :0)

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