P90 magnet questions

Fuhgawz

New member
Hi! I am interested in swapping magnets in my dual P90 Gibson SG Classic. Especially the bridge pickup could use some extra beef and some taming of the highs. I found out that standard Gibson P90's have two A5 magnets, which, according to most people, can be really bright indeed.

After some reading I discovered that the A8 magnet is the thing for me. They should give my pickup more low/mids and output. However, I am not really clear about mixing different types. Some say it's okay to put an A5 with an A8 in one P90, others say that the stronger magnet will 'degauss' the lighter magnet, causing further decrease of power in that lighter magnet. I cannot find how long it will take for one magnet to negatively affect the other magnet to a point that it will be audible. Q1: Does anyone know?

Because of this controversy, and the fact that all commercial P90 producers I could find (SD, DiMarzio, Rio Grande, Bare Knuckle, etc) only use ONE type of magnet, I think I will take the safe route and order two A8's for my bridge pickup.

Then there's the neck pickup. It could be a little less boomy and could use some high/mids. Some P90 producers use A2's, others use A3's. Q2: What do you peole here recommend?

Finally, there's a question about orientation. I found out that magnets should repel. That means either south and south should be together or north and north. But does it matter which part of the magnet is up and which part is down? If your pickups lay south to south and you flip one over over the length of the magnet, they still lay south to south, but another side is now up. Q3: Does this have any influence? Or shouldn't up/down matter, only north/south?

Ah yes, the actual final question! About the whole RWRP thing. The standard Gibson P90's do not come in RWRP sets, so every pickup has either south to south or north to north. Let's say it's south to south and I put in new magnets. Do they also have to be south to south? If I put the new magnets north to north in, the pickups will be RP, but not RW. Q4: Could this cause phase problems when using both pickups or doesn't it matter?

Lots of questions, I hope you nice people here can help me. Thanks in advance!! :)
 
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Re: P90 magnet questions

q1- they may degauss but it will take some time. it seems that many people do it with out any ill effects but i havent tried it myself.

q2- a2 probably wont do it, a3 might be a better choice. maybe one a3 and one a5 to go with the a5 and a8 in the bridge

q3- as long as the two south poles are facing (or north poles facing) it shouldnt matter

q4- if the two pups are magnetically out of phase (one n-n the other s-s) the pups will sound out of phase when both on in the middle switch position. you could make the pups rw by switching the hot and ground wires but with the typical gibson braided shield wire you would want to swap the wires at the pup end.
 
Re: P90 magnet questions

q4- if the two pups are magnetically out of phase (one n-n the other s-s) the pups will sound out of phase when both on in the middle switch position. you could make the pups rw by switching the hot and ground wires but with the typical gibson braided shield wire you would want to swap the wires at the pup end.

Mmm, I find this very interesting! You are saying I could easily RWRP a pickup myself by switching the ground and hot wires and flipping the magnets around? I always thought I would need to unwind the wire around the pickup and rewire it the other way around. I will look into this some more!!

Yup, that's it.

What about using an A4 in there?

Do you mean at the bridge or at the neck?

Thanks you guys!! :)
 
Re: P90 magnet questions

I have modified the Gibson P-90s in my SG Classic thusly:

Neck: A5 + A4 combo.

Result: Smoother tone. Slightly more compressed. Rounder bottom. High-end less shrill but still bright. Greatly improved sounds w/ volume and tone knob rolled back a bit vs. straight A5+A5 setup.

Bridge A5 + A8 combo.

Result: Killer. Thicker midrange and a little more bottom end. Highs are slightly tamed in the ice-pick frequencies but a nice crisp brightness is still retained. Slight perceived increase in output when strings hit HARD, however overall sound seems less compressed - more touch-responsive.
 
Re: P90 magnet questions

I have modified the Gibson P-90s in my SG Classic thusly:

Neck: A5 + A4 combo.

Result: Smoother tone. Slightly more compressed. Rounder bottom. High-end less shrill but still bright. Greatly improved sounds w/ volume and tone knob rolled back a bit vs. straight A5+A5 setup.

Bridge A5 + A8 combo.

Result: Killer. Thicker midrange and a little more bottom end. Highs are slightly tamed in the ice-pick frequencies but a nice crisp brightness is still retained. Slight perceived increase in output when strings hit HARD, however overall sound seems less compressed - more touch-responsive.

+1. You made some nice combinations. You can really get excellent tones my mixing magnets in P-90's. There are boutique PU makers that mix different magnets in their P-90's. I have a pair of Brian Gunsher P-90's that came stock with an A4/A2 pair. I doubt degaussing is an issue. I did my first P-90 magnet mixing a year and a half ago and haven't noticed any waekening. Go for it.
 
Re: P90 magnet questions

+1. A4 + a5 in the neck.

But it all depends on what sounds good in your ears and in your guitar. Could even use a4 + a8 in the bridge, but many might find it too mid-rangey.
 
Re: P90 magnet questions

a4/a5 in the neck is probably the best combo you'll find out there for the neck, especially for an SG. same for a5/a8 in the bridge, you'll have all the cut and treble from the a5 and the fatness and girth from the a8. i also tried a2/a8 in the bridge at one point, but it was too fat without enough treble.
 
Re: P90 magnet questions

Okay, thanks!! So you guys think it is okay to mix magnets in P90 pickups and don't experience any undesired effects? How can you really be sure? The degaussing is a process that slowly takes place. You wouldn't notice overnight anyway. Okay, it may be a dumb question by me (sorry for that!), but I am just wondering. There's just not a lot of information available about this subject.

q1- they may degauss but it will take some time. it seems that many people do it with out any ill effects but i havent tried it myself.

How long do you consider 'some time'? 2 years? 20 years? Does anyone have at least 'some' idea as to how long it will take? 20 years I can live with. The guitar could probably use some new pickups after 20 years anyway. If it's closer to 2 years I might not think it's worth it and would rather just put in two of the same magnets. And why haven't you tried it yourself? Again, sorry for the questions, just trying to get to the bottom of this.

Also, has anyone tried two A8's in the bridge? Could it possibly be too midrangey? I found two builders that offer them, Stan Hinesley and Toneworks, but I could not find reviews of either. Coincidentally (or not), they both offer three kinds P90 pickups with exactly the same magnets and impedence, which makes me suspect there's a link, but I'm not certain.
 
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Re: P90 magnet questions

Okay, thanks!! So you guys think it is okay to mix magnets in P90 pickups and don't experience any undesired effects? How can you really be sure? The degaussing is a process that slowly takes place. You wouldn't notice overnight anyway. Okay, it may be a dumb question by me (sorry for that!), but I am just wondering. There's just not a lot of information available about this subject.

How long do you consider 'some time'? 2 years? 20 years? Does anyone have at least 'some' idea as to how long it will take? 20 years I can live with. The guitar could probably use some new pickups after 20 years anyway. If it's closer to 2 years I might not think it's worth it and would rather just put in two of the same magnets. And why haven't you tried it yourself? Again, sorry for the questions, just trying to get to the bottom of this.

I am not a scientist but I assume it would be a gradual process that probably wouldn't be audibly discernible for a number of years. How many? I don't know.

Buuuut... I don't really care, either. I mean, a pickup bar mag is like four dollars. If it degausses, you're out about 10 minutes and four dollars. No biggie, right?
 
Re: P90 magnet questions

Weeell, you're probably right! I just don't want to change magnets every couple of years. On the other hand, if the sound does degrade noticably, I would only have to change the bars again one more time, back to normal.

So yes, practically speaking, it is probably worth the shot. I just wonder if someone has the theoretical background or extensive practical experience to settle this whole question.
 
Re: P90 magnet questions

I am not a scientist but I assume it would be a gradual process that probably wouldn't be audibly discernible for a number of years. How many? I don't know.

Buuuut... I don't really care, either. I mean, a pickup bar mag is like four dollars. If it degausses, you're out about 10 minutes and four dollars. No biggie, right?

You're not out any money. All you'd have to do is recharge the old magnet by putting a fully charged one on it. They don't go bad.
 
Re: P90 magnet questions

Weeell, you're probably right! I just don't want to change magnets every couple of years. On the other hand, if the sound does degrade noticably, I would only have to change the bars again one more time, back to normal.

So yes, practically speaking, it is probably worth the shot. I just wonder if someone has the theoretical background or extensive practical experience to settle this whole question.

Like I said, I've got some for over a year and a half with no discernable weakening. Gibson uses an A2 & side ceramics in the Tony Iommi signature HB, and that's as extreme in PU magnet stength as you can get (powerful vs weak). Boutique PU makers have been mixing magnets in P-90's for years. You're worrying too much. It works, no downsides, just do it. You make it sound like your guitar is going to explode. Relax man.
 
Re: P90 magnet questions

I am not a scientist but I assume it would be a gradual process that probably wouldn't be audibly discernible for a number of years. How many? I don't know.

Buuuut... I don't really care, either. I mean, a pickup bar mag is like four dollars. If it degausses, you're out about 10 minutes and four dollars. No biggie, right?

+2 with Adam. Worst case scenario = the magnets degause in 2 years and need to be replaced. This will cost you $5/mag and 10 minutes of your time to replace. If you are a gigging musician and only play once per weekend, this costs you less than 10 cents per gig to have the tone that you WANT rather than settle for a tone that's close to what you want.

Don't worry about the miniscule cost and time, get the tone that gives you a big grin and makes you never want to put your guitar down.:18:
 
Re: P90 magnet questions

I have modified the Gibson P-90s in my SG Classic thusly:

Neck: A5 + A4 combo.

Result: Smoother tone. Slightly more compressed. Rounder bottom. High-end less shrill but still bright. Greatly improved sounds w/ volume and tone knob rolled back a bit vs. straight A5+A5 setup.

Bridge A5 + A8 combo.

Result: Killer. Thicker midrange and a little more bottom end. Highs are slightly tamed in the ice-pick frequencies but a nice crisp brightness is still retained. Slight perceived increase in output when strings hit HARD, however overall sound seems less compressed - more touch-responsive.

I'd like to try this on my special....

Stupid question: Does it matter which is on top when combining types?
 
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Re: P90 magnet questions

You're not out any money. All you'd have to do is recharge the old magnet by putting a fully charged one on it. They don't go bad.

Quick question off topic: what would one use to recharge a magnet?

Btw, I am going to order two A8 and one A4 magnet from Wymore. I live in Europe, so it might take some time to arrive, but I will let you guys know when I changed it.
 
Re: P90 magnet questions

I'd like to try this on my special....

Stupid question: Does it matter which is on top when combining types?

I can't believe that noone has made the obvious comments about this. But let it suffice to say that it matters to ME who's on top.:18:
 
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