Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Guitar Pickups - Shapes of magnets used and their importance

  1. Oct 31, 2012 #1
    I'm not electrical minded but I am wondering why my guitar pickup like most have the these rod shaped magnets.

    Why are they that shape and why is it important?

    I would like to make my own pickup to understand better how it functions and to see if I can achieve the attempt in making one.

    But i'm wondering what other shaped magnets I could use instead.

    I know the magnet(s) would have to lay beneath all the strings of the guitar.

    I would like someone to enlighten me some knowledge on this and also answer this question too:

    If they exist as Im not sure if they do, but if I used triangular prism rod shaped magnets instead of the standard cylindrical type, would it change anything drastic? would the pickup work?

    I'm asking because I want my pickup to look different, instead of these round things behind my strings I wanna have triangles instead. I just don't know if it's even possible to do this and whether theres some physical law that states magnets have to be a particular shape to work properlly etc..

    I am a mechanical engineer which possibly explains my lack of intellect due to the overuse of using hammers however please, if you understand what I'm on about and would like to help me out then please do not hesitate to reply.

  2. jcsd
  3. Oct 31, 2012 #2


    User Avatar
    Gold Member

    What you are asking about is pole-pieces, not magnets. If you look at pickup designs over the years, you will find that almost any shape will work for pole-pieces. Bars, rectangles, cylinders, pairs of cylinders... I'm sure that pole-pieces with a triangular cross-section would work just fine, but think of the manufacturing costs. What is easier to make, economically? Machining cylindrical or rectangular pole-pieces is pretty straightforward. Machining triangular pole-pieces or even odd cross-sections like stars, etc costs money with no obvious advantage.
  4. Oct 31, 2012 #3
    If you want to make your magnet unique sounding, you could try a different grade of Alnico. Most pickups use Alnico 3 or Alnico 5. You could even magnetize them yourself if you wanted. I am no expert in the matter but I am trying to magnetize some big alnico blocks right now (you can see it in my 30V 200A pulse thread a few topics below yours). From what I know though, I would suggest against using an Alnico magnet with such sharp angles, because it has very low coercivity vs. remnance compared to other magnets, meaning that it is easily demagnetized unless it is long. I dont own any pickups, but I dont think I remember seeing pole pieces (pieces of iron stuck to the ends of a magnet to guide flux) on the outside of the guitar. Correct me if i'm wrong, but right under each string you have a magnet, I don't think there's a pole piece in between, but i could be wrong. If there is then it really shouldn't make a difference what shape it is so u can make them into stars or skulls or whatever
  5. Oct 31, 2012 #4
    thanks guys makes sense :)
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook