Pickup Theory Question

[ev1ltwin]

Hey all. I'm new to the forum, but I've been lurking here for a while.

I have a general question about pickup construction. I feel like this would be a good forum to pose this question; everyone seems to very knowledgeable about the science behind pickup tone. I realize that there are many factors which go into giving a pickup its unique sound/character. Coming from an engineering background, I'm wondering if we could hammer out all the details. It would satisfy my curiosity, and hopefully it will give us a better way to compare pickups by looking at facts instead of adjectives like hot, compressed, open, etc. which inevitably mean different things to different people.

I'm just gonna list things that I think have an effect on tone:

• gauge of wire used to wind
• magnet type
• size of magnet
• number of windings
• type of pole piece (screw, hex, slug, etc.)
• asymmetry of windings (for humbuckers)

Is there anything else you guys think I'm missing? Feel free to add to the list or call BS on my list.

Thanks to the internets, I feel like I have some grasp on the effect of everything in my list save for the effect the gauge of wire has. Can someone enlighten me on this? Thanks!

[ericsabbath]

wire insulation (enamel, polysol, formvar)

[FELINEGUITARS]

Number of magnets
Length and thickness of magnets
type of baseplate material
Whether the pickup is wax dipped or not - not only can it have a minor effect on percieved high frequencies , it can also anneal the wire whilst it sits in the wax pot and (i believe) raise the inductance, and that is a good thing if I recall what Tim told me.
Covered or uncovered
material cover is made from , and if it is plated etc (and even polished - I've heard that raw nickel has something over polished nickel tone-wise

[Nolly]

Scatter-wound vs. machine-wound
Conductivity of polepieces

[Dizz]

this thread would be even more amazing if anyone could flesh out the specific changes in tone that occur, when one variable is substituted for another. ie: what different gauges/Alnico magnets actually do to the tone.

I just did a quick search on the web and found this paragraph....

MOST pickups are manufactured in the same way. They use a pole piece traditionally a magnet of an alnico alloy (Be careful here, there are several recipes used to create these alloys. . . all impart different characteristics to the sound.) These pole pieces are inserted in a bobbin to ensure exact center to center spacing of the pole pieces and proper alignment with the strings. Around this bobbin is wrapped a tiny copper wire approximately the thickness of a human hair. Usually from 40 to 44 gauge wire is used. The wire is coated with varnish to prevent it from grounding itself out during the winding process. The thinner the wire gauge used the greater the number of turns around the bobbin that can be effected. . . resulting typically in a higher output, but yielding a muddier sound. If thicker wire is used less windings are possible but the pickup will have a brighter sound. Also the distance between pickups (aperture) and the exact position of the pole relative to the string length also effects tone (You know. . . if you strum near the neck you get one sort of sound. . . and picking in close proximity to the bridge yields a brighter, more brittle sound, right?). This is perhaps an oversimplification, but I suspect you're getting the point, that is, that wire gauge, magnet alloy, number of windings, shape of the polepiece, pick up aperture and focal point . . . all of these things must work together to create a great sounding pickup.