Swapping magnets in P90

P

polifemo

New member
I've done a fair amount of magnet swapping in humbuckers but never in a P90.

The original pickup in my old Greco DCJr was a bit too weak and thin sounding and as I also hate P90 hum I replaced it with a Fralin hum cancelling P90.

P1010001-8.jpg



The Fralin IS dead quiet but the sound is a bit boring...

The original P90 reads 7,16k, which is weak for a bridge P90, and I would guess that the magnets are A5.

I've got both UOA5's and A8's (as well as most other types) in the house and would like to hear your suggestions for what to use! (I WILL test and see what I like myself, but all input is much appreciated!)

What about the orientation/polarity of the two magnets in P90s?
 
Re: Swapping magnets in P90

Funkfingers said:
Welcome to the forum.

Tasty guitar.

Before suggesting any magnet changes to the Fralin pickup, it would be necessary to know more about the design of the pickup.

The majority of noise-cancelling P90 replacement pickups employ stacked coils with the magnets sandwiched between. Some Fralin noise-cancelling pickups have two side-by-side coils, sensing three strings each. Photographs of the uncovered Fralin pickup (or its exact model number) would help.

*

Quiet but lifeless is a pretty good summary of every noise-cancelling replacement for a single coil pickup that I have ever encountered. Like many on this forum, I love my Junior and Special type guitars enough to stick with true single coil P90s and live with the noises.

Hence, my suggestion is to leave the Fralin pickup stock. Buy an American-made single coil P90 style pickup. My usual choices are the Anquity or the SP90-3n. (Yes. You read correctly. The Custom for neck/Rhythm position.)
Click to expand...

Sorry, I was being unclear...

I'm thinking about putting the old pickup back but with other magnets in order to see if it's possible to make it fatter sounding.
 
Re: Swapping magnets in P90

If it uses standard bar magnets, you can replace them. They lay side-by-side repelling in true P-90's, not sure what you have going on in the noiseless one. For orientation, pull the old mag out halfway, hold the new one up to it so the ends repel and sides attract.

I re-popularized magnet swaps in P-90's here a few years ago. I like warm, full-sounding bridge PU's, and pull the twin A5's out of my bridge P-90's, and replace them with various combos: A8/A4, A8/A5, A4/A4, & UOA5/UOA5. They fill in the mids and reduce treble.

Describe 'lifeless.' What part of the EQ is lacking? If it's high end, swapping to warmer magnets won't help; A5's are the brightest alnico. Do you want more output? A8's give that.

You might be better off with a true P-90 and mag swapping to dial in your tone.
 
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Re: Swapping magnets in P90

See reply above your post.

I was very unclear about my plans...
Sorry about that!
 
Re: Swapping magnets in P90

Excuse me, while I decorate the sidewalk.

:earl:
 
Re: Swapping magnets in P90

As the pickup I'm about to swap magnets in only reads 7,16k I suppose that a OUA5/A8 might be a good combo, the OUA5 reducing some high end as well as fattening the mids a bit while the A8 compensates for the low DC resistance.

I'll give it a try but I'll probably end up ordering a Zhangbucker or a Lollar P90.
 
Re: Swapping magnets in P90

Funkfingers said:
Try all of the permutations open to you. In the interests of objectivity, record audio clips of each. Leave the records for at least a week. Check them out again. Decide which (if any) you like.
Click to expand...


A good idea indeed.

I have a feeling however that the pickup is a bit to weak to start with in order to sound good in the bridge position...
 
Re: Swapping magnets in P90

Try not to get too hung up on pickup specification statistics. Gretsch Filter'Trons (and good replicas) have a surprisingly low DC Resistance but still have plenty of output.

Changing the magnets could well bring the improvement that you desire.

It would be easier to suggest replacement pickups if we knew what amplification and/or pedals you play through and in what style(s).

My own taste is for all-valve amplification, set for overdrive that will vary according to my playing dynamics - or adjustments of the guitar's volume control. A pickup of vintage level output should be enough to play this way. Hotter pickups will drive you amplifier harder but you will lose some of the dynamic sensitivity.
 
Re: Swapping magnets in P90

I would suggest that the first thing you try would be to replace one of the A5 mags with an A8 and see how it sounds. If it an improvement (which it most certainly would be) but not quite enough, then change the other to an A8 as well and go from there. Pay close attention to polarity as Blueman has said. When properly oriented/installed, the two magnets should repel each other.
 
Re: Swapping magnets in P90

Swapped some magnets in that old Greco P90 but nothing could change the fact that the top strings are really wimpy sounding...

The basses sounded bright, alive and fine, the mids could have been fatter but were ok while the treble remained to piercing.

I guess that this pickup could sound nice in the neckposition but as a bridge pickup it lacks balls (even with A8's).

The Fralin is back but I might try a punchier (true) P90 later on.
 
Re: Swapping magnets in P90

Have you tried raising the treble side of the pup closer to the strings and lowering the bass side away from the strings...so the pup will be at an angle?

If so, you might want to think about different strings.
 
Re: Swapping magnets in P90

+1 for strings. Gotta be 10-46 minimum.

If the Fralin noise-cancelling pickup has four-con + shield cable, consider adding a variable coil split. Use a micro trim pot. Conceal it in the control cavity. The idea is to strike a balance between noise-cancellation and tone. Set and forget.
 
Re: Swapping magnets in P90

I use 10's for strings.

The Fralin is OK for live stuff when there are lot's of noise when using single coils, and especially P90's!

I'm using 50's wiring + a treble bleed circuit so that when I roll down the volume a bit I get pretty good "vintage P90 tones".
(What I've also done, which probably seem a bit strange, is to add a "de-mud mod" - most often used with boomy neck HB's - as this P90 was to fat in the low end for my taste)
Still I just ordered a Tyson Tone Lab "60 Wraptail 90" that I will use when so is possible.
 
Re: Swapping magnets in P90

The Tyson Tone Lab P90 reading 8,8k I don't think that the A8's will be needed.
It comes with 2 roughcast A2's and if I feel the need to tweak it - which I hopefully won't - I'll probably mix in a roughcast A4 or an OU5.
 
Re: Swapping magnets in P90

Two questions that probably should have been asked earlier.
1) What sort of amplification do you play through?
2) What brand are the pots in the Greco?

On my P90-equipped guitars, the volume control pots are as much a means of governing overall valve saturation as they are for rolling off outright volume. In my opinion, the treble bleed (AKA treble bypass) modification defeats this use of the controls. I prefer audio taper pots over linear. I prefer American pots over Japanese.


EDIT - I just re-read posts 13 and 17. You have a treble bypass network and a de-mud mod, then you complain that the guitar is too trebly. Ho, hum.

:scratchch
 
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Re: Swapping magnets in P90

The treble bleed circuit and the de-mud mod is being used with the Fralin hum cancelling P90 which is not too trebly. On the contrary it is way too fat in the lows and not at all too trebly in the highs.

It's the original pickup that is too thin sounding.

With the Fralin I use CTS 500k pots and with the original pickup I use the original which are 250k pots. (With the original pickup I do not use the treble bleed or de-mud mod)

Regarding amps I use way too many to list here, but they're all tube amps. Regarding speakers it's mostly "Greenback style" speakers of different brands.
 
Re: Swapping magnets in P90

polifemo said:
The treble bleed circuit and the de-mud mod is being used with the Fralin hum cancelling P90 which is not too trebly. On the contrary it is way too fat in the lows and not at all too trebly in the highs.
Click to expand...

Sounds like the standard complaint about stacks and other hum-free "single" coils...
 
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