Original post by Cheebatone:

Can somebody please, please give me a Pick-up Wiring 101 lesson on...

a) Series and Parallel (I know the electrical difference, but that's about it.)
b) In and Out of phase (I thought I knew the audible difference, but it turns out I'm wrong. See above.)
c) Windings and poles (I know nothing.)

...in a simple; "A Tele/Strat/Les Paul is wired like this... and sounds like this... beacuse of this...", sort of fashion because I've raised questions like this before only to have people use expressions like, "...what you need is a DTDP" and I've always thought that's what you put down to kill rats.

Please help a dumb-ass.



Jim Collins:

I'll try the phase question, first. Way back, in the first level Physics class (now, this was back when electricity was brand new), we learned a memory trick called the Right Hand Rule, and it comes in handy, here. Make your right hand into a fist, with the thumb pointed out, as if you were hitchhiking. Your thumb represents magnetic north, and your fingers point in the direction of current flow. No matter how you orient your right hand, the fingers and thumb still share the same relationship. So it is with magnetic field and current.

This is exactly what a pickup is -- a coil of wire around a magnetic field. As long as each pickup is wired in the proper direction of its own current flow, the pickups will be wired in phase, no matter the orientation of the magnetic field of the individual pickup. If you change only one of these variables in a single pickup -- either wiring direction or magnetic polarity -- that pickup will be out of phase with the others.

In a vintage Strat, all three pickups shared the same magnetic polarity, so all three were wired the same way. In a modern Strat, the middle pickup has reverse polarity. For it to be in phase with the other pickups, it has to be wired to accommodate the reverse flow of the current, which means backwards.

The fact that each of a Strat's pickups is rather thin sounding (as opposed to a P90 or a humbucker), and with relatively low output, means you will tend to hear two, distinct sounds when two of them are in the circuit, in parallel. A Les Paul's middle position is also two pickups in parallel, in phase, but because the pickups are fatter sounding, to begin with, your ears don't have as easy a time distinguishing between the two sounds.

A pickup's output is like a sine wave. The first half of the wave is above the x-axis and the second half is below. If you were to superimpose an identical wave on top of the first wave, but invert it -- make it out of phase -- the two waves cancel each other out, and the result is no sound. If you take the neck and middle pickup in a Strat, they won't produce exactly identical sine waves, simply because they are working on different parts of the string, which have different timbres and different energy levels. If you were to invert one of those sine waves, by connecting one pickup out of phase with the other, the waves would not cancel each other completely, simply because they are not identical, but they would cancel a significant part of the sound. That is why out of phase sounds are so thin and nasally.

Some people like out of phase sounds, and some don't. Out of phase sounds work better, I think, in a guitar with Gibson-style wiring, in which each pickup has its own volume and tone controls. Vary the volume and/or tone of just one of the pickups, and you alter, significantly, the quality of the out of phase sound. Stick with the Strat-style wiring, and you do not have the opportunity to do anything but vary the volume and tone of the combined sound.

Parallel vs. series has nothing to do with phase relationships. Just as parallel sounds can be in or out of phase, so also can series sounds be in or out of phase. The typical humbucker features two coils that are in series and in phase with each other, although modern, four-conductor wiring allows you to change that. (The two coils are also RWRP with respect to each other, which cancels hum, but, again, modern, four-conductor wiring allows you to wire one of the coils backwards.)

If two coils are in parallel, they are, for the most part, independent. The beginning and end of each coil ultimately end up in the same place, and you get two tones that combine to form a pleasing tone, but the output of the pickups is not additive -- two parallel coils are not louder than one of the coils, alone. If the coils are in series, the output of one coil is used as input to the next coil, and the resultant output is additive. If the two coils are in phase, as well, the resultant, added sine waves produce something that not only has greater amplitude (height) but is also fatter. That is why two coils in series (and in phase) sound fatter than the same two coils in parallel (and in phase).

What is it you'd like to know about windings and poles? By "pole", do you mean magnetic polarity, or "pole" when used in the context of switch descriptions, as in double pole, double throw?