I have several old Bass Humbuckers that I have collected over the years that need their magnets re magnitized. Anyone have a clue as to how and where I may be able to get this done ?? Thanks !!!!
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Re Magnitze Bass Humbucker Magnets ? HELP !!!!
- Thread starter 51pbass
- Start date
- Aug 21, 2008
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- Owner, SGD Music Products
David, I wonder how this happens? Bill Lawrence says to store unused pups so the mags never touch another pups mag or any metal object and they will remain mag'd indefinitely. Your thoughts? How long can one expect mags to remain useable in a pickup?
- Aug 5, 2005
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Demagnetization can occur with heat and physical stress as well, so it's not just the presence of opposing magnetic fields that will do it. All of that depends on the magnetic materials, because some of the stronger magnets frequently used in pickups wont undergo much physical stress in a pickup housing and aren't often stored above 250 degrees F (or whatever the exact Curie temperature happens to be for each magnet).
I agree with the statement that with most pickups, proper storage will keep them magnetized well past the age where you can no longer play the bass.
- Aug 21, 2008
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I'm guessing the pickups were in a box or drawer or something, and around other pickups.
If you push two opposing alnicos together you can weaken them. If you do that with a alnico and ceramic, you can demagnetize the alnico quite a bit.
Ceramic magnets on the other hand are very hard to demagnetize.
Neodymium magnets are almost impossible to demagnetize, and are in fact often used to magnetize alnico magnets.
- Aug 21, 2008
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It's probably a good idea to try and keep them separated. They can be next to each other, but don't let the faces stick together.
That's exactly what Mr. Lawrence says, thanks David! Makes sense since alnicos are magged after assembly; they would be susceptible to demag under the right (wrong) conditions.
Well You guessed wrong. I know how to store pickups my friend .Just need to get them remagnatized. A guy from L.A> contacted me and my problem has been solved. Thanks.
- Aug 21, 2008
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OK so how did they become demagnetized?
Magnets don't just go dead, my friend. That's from being around other magnets or magnetic fields. Period.
- Aug 5, 2005
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OK so how did they become demagnetized?
Heat and physical stress can cause demagnetization, but the opposing magnetic field option is the only one that makes sense under any normal circumstances.
For those interested:
Magnet - Wikipedia, the free encyclopedia
- Aug 21, 2008
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You have to heat alnico up to 1,470°F to demagnetize it! They start to lose power at 538°. Ceramic magnets have a curie point is 860°F. Neodymium is only 590°F, and they start to lose power at 176°F.
I have pickups that are 40 years old and the alnico magnets are fine.
I actually own a business that sells magnets, here's the lowdown.
It's true that vibration can demag Alnico materials, the heat required to demag it is very high and will not be part of the usual atmosphere a bass could live through, the same applies to the ceramics. Neo has a fairly low curie point, but again, way beyond what your bass would typically experience.
As the player of a early 70's Rickenbacker, I'm casting a dubious eye at my pickups, even ones I've had re-wound. Rewinding with the correct gauge is critical to re-achieving the same sound and output.
One thing that is overlooked, and i can't really say how much this applies to bass pickups, is irrecoverable losses. These are losses that are very small ( 0.02% ) as the material is cycled up and down the temp curve. In our industry , we will use a rule of thumb that states we'll assume losses of 3-5% over 10 years. For most magnet applications, this is meaningless, except for closely calibrated applications. With modern sound equipment, I would be willing to put stringed instrument pickups in that category of closely calibrated applications. They get old, they lose a bit of field strength.
It's true that vibration can demag Alnico materials, the heat required to demag it is very high and will not be part of the usual atmosphere a bass could live through, the same applies to the ceramics. Neo has a fairly low curie point, but again, way beyond what your bass would typically experience.
As the player of a early 70's Rickenbacker, I'm casting a dubious eye at my pickups, even ones I've had re-wound. Rewinding with the correct gauge is critical to re-achieving the same sound and output.
One thing that is overlooked, and i can't really say how much this applies to bass pickups, is irrecoverable losses. These are losses that are very small ( 0.02% ) as the material is cycled up and down the temp curve. In our industry , we will use a rule of thumb that states we'll assume losses of 3-5% over 10 years. For most magnet applications, this is meaningless, except for closely calibrated applications. With modern sound equipment, I would be willing to put stringed instrument pickups in that category of closely calibrated applications. They get old, they lose a bit of field strength.
Well, if it's true then there's something really, really wrong here
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- Aug 21, 2008
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- Owner, SGD Music Products
Well, if it's true then there's something really, really wrong here
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Whats really wrong is your understanding of what you are looking at.
Nothing is wrong there because of the way the magnets are oriented. I said pushing opposing poles will weaken magnets, right? That means North to North.
What do you see in that picture?
Assuming north is facing up, and south is facing down, the magnets are attracting, and not opposing, and this is the way you want to store pickups, as long as they are the same type and strength of magnet.
Understand?
Another thing, the OP said humbuckers. Unless they are Music Man humbuckers, which use rod magnets, most humbuckers have steel poles and a bar magnet connecting those poles together at the bottom. The poles on top form an open gap.
Whats really wrong is your understanding of what you are looking at.
Nothing is wrong there because of the way the magnets are oriented. I said pushing opposing poles will weaken magnets, right? That means North to North.
What do you see in that picture?
Assuming north is facing up, and south is facing down, the magnets are attracting, and not opposing, and this is the way you want to store pickups, as long as they are the same type and strength of magnet.
Understand?
Another thing, the OP said humbuckers. Unless they are Music Man humbuckers, which use rod magnets, most humbuckers have steel poles and a bar magnet connecting those poles together at the bottom. The poles on top form an open gap.
Just joking man, relax ok?
- Aug 21, 2008
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What does rewinding have to do with magnets becoming demagnetized?
I own two '73 Ricks with long magnet toasters. Those alnico magnets are still at full strength.
All Rick pickups are wound with 44 AWG wire.
It's easy to check magnets with a gauss meter. I have old Fender pickups, some Jazzmaster pickups from 1959, and some Mustang pickups from '72. I also have one bobbin from a '74 P bass. These all read full strength, except for one Mustang pickup which had been in a parts box with some ceramic magnet pickups. That lost most of it's strength. Butt it was a simple matter to recharge it with a couple of neos in a charging jig.
- Aug 21, 2008
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- Owner, SGD Music Products
Just joking man, relax ok?
Well you don't want people reading this that don't know any better to think that's a bad thing.
That's exactly the way you want to store those pickups, and not face to face, which is what I said. But even when you have magnets stuck together, either in pickups like that, or in a block, which is often how you get them when you buy a bunch, you have to peel the alnicos off slowly as to not demagnetize them.
- Aug 5, 2005
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- Endorsing Artist: J.C. Basses
