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P-90 magnets


 
4/27/2003 7:42 PM
Steve A.
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P-90 magnets
    I may have a set of P-90's custom built for me and I was wondering how the different magnet types would effect the sound. The choices are Alnico 2, Alnico 5 and ceramic. I'm looking for clearer P-90 sounds like Bloomfield's LP GoldTop on the first two Butterfield albums rather than the George Thoroughgood "Bad to the Bone" Tone (or is that more a factor of the amp settings?)  
 
    BTW has anyone here tried Alnico 3 slug magnets in Fender-style single coil pickups? They are used in the 52 Tele RI and for the No-Caster pickups, and they sound different from Alnico 2 or Alnico 5. Alnico 3 is supposed to be weaker than 2 or 5.  
 
    BTW Part Two... I just noticed that Lindy Fralin is offering P-90 pickups with magnetic pole pieces instead of the bar magnets on the bottom. They are supposed to be clearer than the normal P-90's. Has anybody here tried building them like that?  
 
--Thanks!  
 
Steve Ahola
 
4/28/2003 3:02 AM
Shea
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Re: P-90 magnets - check out Steven Kersting
Steve -  
 
I bought a set of Steven Kerting's HB90s - that is, P-90s in standard humbucker dimensions. He used alnico magnet polepieces in the neck pup, and they suit it really well. They have a broader tonal range and they're a tad smoother. The bridge pickup gives me that "Bad to the Bone" nasty, midrangey honk, which is exactly what I wanted.  
 
I really recommend doing business with Steven. Besides the good pickups he makes, he has fast response time, his prices are reasonable, and he's a straight shooter.  
 
I certainly don't know the diff. between the the different types of alnico.  
 
Shea
 
4/29/2003 1:40 AM
Jason Lollar
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putting the Fender type poles in a P-90 makes the top end more "boinky" or fendery.  
The wonderful thing about P-90's with bar magnets is the way the tone changes when you roll off the volume, the mids drop out and they get clean, put magnetic poles in and they act like Fender pup's, roll down the volume and the highs drop off.  
 
both sound good.
 
5/1/2003 4:52 AM
Steve A.
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Jason:  
 
    Thanks for the info! I think that maybe I should stick with the traditional bar magnet design since I already have plenty of "boinky" Fenders... ;) I was checking out what you said about turning down the guitar volume on my LP Jr (with a single P-90) and it is certainly true... the mids drop out a bit and the tone gets brighter.  
 
    Now I just need to decide what type of magnet... I noticed that many of the boutique builders are using ceramic. Is that for higher output? Did Gibson use Alnico 2 and/or 5 for the P-90's back in the 50's? Do you know what Gibson is using on their current P-90's? I'm really looking for an authentic goldtop tone, like early Bloomfield with Butterfield. From your comments I guess that he had the guitar volume controls turned down a bit to get those sweet blues sounds.  
 
    Thanks again!  
 
Steve Ahola  
 
P.S. I see that Gibson introduced the Blues 90 pickups in 1996 in their Blueshawk guitars, with the Alnico pole pieces; the Blueshawk guitars also used a dummy coil (evidently a Blues 90 with no pole pieces). I guess that could also be done with a regular P-90 by just removing the magnets and pole pieces... has anybody here worked with dummy coils for P-90's?
 
5/1/2003 9:00 PM
Jason Lollar
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I wouldnt say it sounds exaxtly like a Fender because the scale length is part of that but they do wind up sounding very close to a jazzmaster pickup when you put alnico poles in them.  
 
Ceramic would normally be used for higher output, I dont recall what gibi used in P-90's in the 50's.  
You watch guys that play trad blues and they constantly work thier volume and tone controls and they switch from using a pick to fingers and use the pickup selector alot, alot of them just play with thier thumb and one or two fingers. Its all about getting a wide variety of tones out of a limited set up.
 
5/7/2003 2:07 AM
Steve A.
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I wired up a dummy coil...
    I thought I'd give this a quick shot to see how it worked. I took apart a cheap Epi P-90 with a DC resistance of 8.36k and wired it up in series with a Gibson P-90 with a DC resistance of 8.0k:  
 
" target="_blank">http://www.blueguitar.org/new/pix/dummy_coil.jpg">  
 
    So how did it work? Well, on the positive side, it eliminated most of the hum (I tested it with a TV on). As for the sound, it worked fairly well with the full-on "Bad to the Bone" setting of the P-90, adding some compression to the sound, but something I could live with, not completely unlike the compression from an amp that is cranked up.  
 
    The big drawback to me is that as you turn back the volume, you don't get the sparkley clean tones of a P-90. :( So I would definitely want to be able to switch out the dummy coil with a push pull pot.  
 
    For the heck of it I tried wiring up the dummy coil in parallel, and the sound is way too bright and there is a very noticeable drop in volume. It might be interesting to experiment with caps and resistors to cut the treble a bit, but I think that I will pass on that experiment for now.  
 
    I was thinking about routing out a cavity on the back of my LP Jr for the dummy coil but it would make more sense to put it right under the dog-ear P-90 (some routing my be required to get it to fit but better there than on the back of the guitar!) The position of the dummy coil didn't seem to matter much once I flipped it around for the correct orientation.  
 
    In any case, many guitarists have mentioned that they love P-90's but just can't handle the hum. I think that adding a switchable dummy coil would help a lot, especially for distorted leads.  
 
Steve Ahola  
 
P.S. Adding a dummy coil to a guitar with two P-90's would be more complicated if one of the P-90's is RWRP. You would need to reverse the leads from the dummy coil when switching from one pickup to the other, and you would not want the dummy coil in the circuit when both pickups are selected. Easy enough to do with a rotary switch or a strat style megaswitch, but I'm not sure if there is a multi-pole switch available that will mount in a LP that would look stock.
 
5/7/2003 12:33 PM
SK
For the heck of it I tried wiring up the dummy coil in parallel, and the sound is way too bright and there is a very noticeable drop in volume.
That doesn't sound right to me...sounds like it was out of phase.
 
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