Magnet swap and other pickup mods

[Eric Schmitt]

I have a box of cheapie humbucker pickups that are just sitting in a box collecting dust. I want to get into winding & modding pickups and figured these things might be a good place to start learning. My thought are to take these spare pickups and instead of pulling them apart and rewinding and whatnot, I'd try doing some modification to them as a start (swapping out the magnet, pole pieces/slugs, base plate, etc). Of course I have a couple of questions for the experts:

1. Is there any good way to tell what kind of magnets are already in them?
2. How about the pole pieces, any way to tell what they may be made of?
3. The set I want to start with is in the 8-9 Kohm range, can I assume they would have 42 gauge wire wrapped in the 5000 turn per bobbin range?
4. The base plate appears to be brass, would changing this to a different material make any difference and if so what kind of difference?
5. Not that I'm going for any specific sound but how would one roughly predict what kind of tone they would have?
6. Lastly, As I've searched the web for info on pickup construction, materials, and how they affect tone I've come across all kinds of contradicting information. What are some good reliable sources to get more info on this subject?

Thanks in advance for any help!

[David King]

Identifying magnets takes a Gauss meter and a good way to charge them to full capacity at the very least. A2 will be a bit hotter than A3 and A5 will be a bit hotter than A4. You might be able to analyze the slugs on a high speed grinder in a dark room if you have some known samples to compare sparks against but identifying 1018 vs 1022 will require some serious equipment and knowhow.
Replacing the brass baseplate with nickel silver probably will make a small difference.
A good source of information would be someone like Veronica Merryfield who just gave a talk about it at the GAL conference last month. That write up will appear in future GAL publication. Short of that start reading wikipedia entries on magnetism, electromagnetism, guitar pickups etc.

[Eric Schmitt]

Thnaks for the info david, I look foward to reading that article when it comes out.

I don't have any meters or anything to analyze the current components so I guess my best course will be to swp components out to things of known values & materials and go from there.

I minored in physics in college so I have a good background of electromagnetics, magnetist and how things interact in a general terms. My short-comings is how all of this relates to guitar pickups and its effect on tone. That's the part I'm really trying to get info on, and this is where I'm getting all the contradicting info. For example you say A2 magnet is hotter than A3, some sources agree with that while others I've read say the opposite. I'm not doubting you or doubting the sources I've read as it may be misuse of terms; as in maybe to one hotter = more highs where to another hotter = more output or muddy = lots of bass end vs muddy = loss of clarity. Or there's the ever popular "this = crap" with no other evidence other than they don't like it. This has been my biggest source of confusion.

I guess maybe I should change my approach to this project. Instead of reading contradicting info on how components effect tone I should go ahead treat it like a R&D experiment and get some different magnets, poles, baseplates etc., swap things out one at a time, and record my observations. in the mean time if anyone has some more info on the subject or even better some sound clips that demenstrate the differences that would be helpful and greatly appreciated.

[Jason Rodgers]

I don't have any meters or anything to analyze the current components so I guess my best course will be to swp components out to things of known values & materials and go from there.

I guess maybe I should change my approach to this project. Instead of reading contradicting info on how components effect tone I should go ahead treat it like a R&D experiment and get some different magnets, poles, baseplates etc., swap things out one at a time, and record my observations.

Good thinking. I don't think you could get a better education on the subject.

[Eric Schmitt]

So I did a magnet swap on an old ibanez INF2 stock pickup from A5 to ceramic magnet. I did notice a change in tone right away but in general how long does it take for everything to fully adjust to the new magnet, few hours, a day, a week?

[Jason Rodgers]

Instantaneously, I would think.

[Eric Schmitt]

My experiments are coming along nicely, I've learned a good bit so far and have been having fun with it. I decided to do my tests on a spare Ibanez INF2 pickup I had laying around. So far, along with the stock A5 magnet, I've tried out A2, A8 & ceramic magnets. I'm still waiting for a few magnets to come in the mail to try out but here are my observations so far. All sound tests were done on a basswood V style guitar maple/rosewood neck. All the amp settings remained the same, eq-ed pretty flat across the board & same volume levels. Pickip height was consistant with all the tests also.

A2 - Really nice mids, lows are pretty tight and light on the highs. It gives the pickup a really nice crunch tone with a lower vintage output. It reminds me of a PAF style pickup. I did notice a perceived volume boost compared to the stock A5, my assumption for this is that it comes from the boost in mid range frequencies. Overall I say it's a good fit for that crunchy classic rock rhythm sound.

A5 - This was the original magnet. The Eq on that was good highs & lows but scooped mids It wasn't as full sounding as the other magnets and seemed to have a lower volume output. Again I'm attributing this to the mid frequencies or lack of them. Overall it was good but it sounded comparatively weak & bland.

A8 - Very similar in tone to the A2 but more balls to the walls. Really nice mid range, tight lows and lighter on the treble but not lacking in them. As expected with a stronger magnet it had more output, it turned the pickup into a beast (in a good way). This would be perfect fot that in your face crunchy heavy metal rhythm sound. It's by far my favorite of the ones I've tried.

Ceramic - It has about the same output as the A8 but with less mids and more trebel; the lows are nice and tight. It's very articulate in high gain settings. I would say it a good fit for classic rock & heavy metal lead guitar and still work well for rhythm. This setup would be my 2nd favorite.

When switch magnets I did observe that when changing from a weaker to stronger magnet (A2 to A8) the changes were almost immediate but when switching from a stronger to weaker magnet (Ceramic to A2) it took about a day to notice any changes. My theory on that is that the other metal components in the pickup held on to the stronger magnetism for a while before it adjusted to the weaker magnetic field.

Like I said I still have a few more magnets I'm waiting on to be delivered (A3, A4, A6, A9, and an unoriented A5). Once those come in I can finish up my experiments. I'll post a full observation analysis / comparison and try to post some sound samples for those who are interested.

[David King]

Eric,
This is a great baseline series of observations. I don't know this particular pickup at all so I have no idea what parts of the armature might be storing residual flux when changing from a stronger to a weaker magnet. It might be handy to pickup a little handheld demagnetizer and see if you can hear those differences right off the bat. If you have a way of making sound sample snippets and posting then we could all come crashing in with our binders full of adjectives.
I also wonder if your A5 is a little low in the Gauss from when it was new. You might need to juice it up. Also many people claim to hear subtle differences between batches of A5 and different vendor's magnets in general. I've heard more than one pickup maker rave about the A2 from Azindustries for example (but only in the context of Telecaster pickups.)