Humbuckers changin

WHen will i know i have to change my humbucker pickup and how long should they last me?

They should last you a lifetime, they are basically just magnetic poles wrapped round with copper wire.

Do you remember your physics lessons, if you move a piece of wire (like a guitar string) in a magnetic field you generate a small amount of electricity and that is exactly how a pickup works. So, nothing to go bad or replace !

You know it's time to change them when the guitar they're in is decent but you're sick/tired of how it sounds and/or it doesn't fit what you need.

hmmm.. interesting question. so, butting in this nice conversation, if my guitar lives perfectly in tack in 200 years, the pickups would still be working perfectly? is there such a thing as a weakened magnet?

I think there is such a thing as a weakened magnet, since that's one of the selling points of a vintage, NOS guitar that I read about in a Fender catalogue.

Makes sense that a magnet would weaken over time, at least to my layman brain.

but does a magnet weaken over time though?

Originally posted by the fool
but does a magnet weaken over time though?

Ummm...

Originally posted by iamthe_eggman
Makes sense that a magnet would weaken over time, at least to my layman brain.

Only if you hit it with a hammer

geesh! sorry. I guess I'm just a layman too. LOL

dr. simon
but isn't it possible for a a magnet to weaken over time? look for instance the magnetic field of earth hasn't it been reported in the news that it has weaken quite a bit?

That could explain why I've only seen like one compass point north in my life. :P

erm i could be wrong... but aint pickups electro magnets??? im not sure bout normal magnets but these deff dont weaken. however they may start to become magnetic when un plagged over years of constant use ...

or perhaps corosion of the metalls might efect the efficiency of the pickups..... aghhh i dunno il stop pretending i know what im on about now.

'active pickups' are electro-magnetic.
As far as I know,Magnets DO weaken over time.An old 50's fridge magnet might fail holding a piece of paper to the freezer today...but I dont know how pickups age as the magnet is more substantial,wrapped...
Good question.

I am no expert here so don't take my word for it but....

From the precept that a magnetic field is created by substances that are composed of polarized ions, I think the answer is that different substances polarize and remain polarized for varying times, some better (longer and more completely) than others,

As far as guitar PUs are concerned I don't think you have a lot to worry about, A vintage axe's PUs may sound week next to some newfangled super high out put mega-metal PU on account of the latter having stronger magnets with more copper wire wound round them. This does not mean the new fanged PUs will sound better simply because they have a hotter output.

As far as the decay of earths magnetic field is concerned, that is again due to the nature of substance crating the field, In this instance I think it is molten iron which is in motion. As motion and polarity are not really compatible the field is decaying.

Lordathestrings would be a good person to ask about this and probably knows considerably more than me !

Lordathestrings? Are you there? I know you're just around in the corner moderating some threads... can u join our lil' discusion?

hmm...

• [u]All[/u] passive pickups use 'permanent' magnets. As the good Doctor pointed out, these are formed by aligning the magnetic poles of the material. I don't know if it's done at the atomic or the molecular level, but once formed, a magnet will stay magnetised unless something is done to it to reduce the uniformity of the magnetic polar alignment.
  



• Physical shock, high heat, or the presense of a strong, varying magnetic field are the sort of things that could reduce the strength of a magnet. The kind of magnetic materials in pickups are specifically chosen to retain their magnetism very well.
  



• There are measurable differences in the way different magnetic materials react to fluctutions in their magnetic field. This is the basis for the distinctions made between Alnico and Ceramic magnets, for instance.

Interesting and very informative as always. thnx for sharing us some of your vast knowledge mr. moderator sir.

just have a couple of questions regarding this particular post:

"Physical shock, high heat, or the presense of a strong, varying magnetic field are the sort of things that could reduce the strength of a magnet. The kind of magnetic materials in pickups are specifically chosen to retain their magnetism very well."

does this mean that if, let's say, my guitar is not properly wired and i get electrocuted, it can also damage the pickups in my guitar?

also, (this one sounds silly but i'm gonna ask it anyway) does this mean that by placing my guitar in places near electonic equipment that uses magnets like a tv, i also risk ruining my pickups? I just had to ask because my basement is damp, cold, and wet especially during this winter season and most of my equipment is in my very small room, so its basically just besides the tv and stuff.

To answer your first question: If you get electrocuted, your heir can worry about the pickups.

For the rest:

This is an excerpt from the Q & A page at the Weber VST website. The answers are from Ted Weber himself. The man knows speakers!

From: Shawn Bolton
"I think I understand your explanation of the differences between AlNiCo and Ceramic magnets in speakers, but what do people mean when they say modern AlNiCo is different than old AlNiCo or that it has a half-life?"

"Shawn, I hadn't heard about the belief that old and new AlNiCo are different, however they are one and the same. For speaker applications, AlNiCo 5 is the best choice in the AlNiCo family of alloy magnets. Its peak energy product is just right for loudspeakers where we need to concentrate high densities of magnetic flux in the gap around the voice coil. AlNiCo 5 is an alloy made up of 8% Aluminum, 14% Nickel, 24% Cobalt, and 3% Copper. The cobalt is what makes the AlNiCo expensive. Most of the worlds supply comes from the African country of Zaire. Besides that country controlling the market, cobalt is also a strategic metal used in missles and other weapons systems. It currently sells for about US $32 a pound.
As far as it having a half-life, that's another new one on me. When a speaker is put together, the magnet is initially uncharged, or unmagnetized. Then, at the end of the assembly line, just before testing, the speaker is passed under a huge electromagnet that zaps the magnet with about 10 to 20 times the magnetism that would be required to saturate the magnet. After the electromagnet is turned off, the speaker magnet immediately loses about 2% of its magnetism and then stabilizes. In the next year, it drops another 1%, and then is essentially stable for thousands of years. Unlike a flashlight battery, the magnet is not being used up or depleted of its energy while in use. All that has happened is that we have forced many of the tiny molecular magnets called domains to realign themselves in one direction. Once 'flipped', they reach an equilibrium and stay there. Besides intentional demagnetization with a demagnetizer, there are three situations that can cause a magnet to become partially or fully demagnetized, and this may be what the half-life comment is all about. The first one is excessive heat. That's not a consideration for speakers because the temperature to demagnetize an AlNiCo magnet (called the curie point) is over 1000 degrees F. The second is from a large, changing magnetic force. This could happen in a speaker. The typical case would be where a person blows out the speaker by using excessive power. The high value of magnetism produced by the voice coil could partially demagnetize the magnet. This is why you should always ensure that anyone who is going to recone a speaker for you have a magnetizer to renew the charge on the magnet, just in case it got partially demagnetized. The third and final situation is physical shock. If you dropped an AlNiCo magnet speaker and it happened to land on the corner of the magnet frame, it could partially demagnetize the magnet."

I recommend spending some time browsing this site. There's a lot of good information here. In particular, I found the user comments very helpful when I was deciding what to install in the Ampeg VT-40 I rebuilt last year.
:)

Cool! Thanx man, that's very informative. Now that you've brought out the topic of alnico 5 magnets and how they're good with speakers and stuff, I would like to ask- which would be a better guitar pickup? the alnico 5 or the alnico
2? I was trying to figure out what are the stock pikcups that my epi has before i replaced them with classic 57 and classic 57 plus (both alnico 2), so I sent pics and sent it to Gibson. Roger Ball, the customer support dude told me that the stock pickups were a 57 humbucker and a hot humbucker which are both alnico 5. I don't remember how they sound like because I immediately replaced these pickups a week after I got my guitar. Are these alnico 5 pickups suppose to sound better than alnico 2's?

You're asking me what sounds [u]better[/u]? :confused:

I do know that Alnico magnets have some compression qualities that makes them sound different from ceramics under some circumstances. The difference between Alnico 2 & Alnico 5? The numbers probably refer to the percentage of one of the elements in the alloy (most likely the Cobalt - it's the expensive part), but I have no idea what differences there might be in the sound, much less which one you would think is better.