which is positive/negative wire????

[d14099]

i am new to this and need to know the best way to determine the positive and the negative on a single coil p/u that has two seperate wires,

[ashcatlt]

Welcome aboard!

The answer is unsatisfactory. Neither is + or -. We're dealing with AC, so they swap polarity fairly rapidly. Unless one of them is connected to a metal shielding around the coil, it doesn't matter which end is connected where if the pickup is all by itself.

Now, if you've got another you'd like to use with it, you'll want to be sure that their relative phase is the same. This requires testing both pickups. All you need is a screwdriver (or other ferous object) and a volt (or multi) meter. Alligator clips are nice.

Connect one of the meters leads to each of those from the pickup to be tested. Put the screwdriver very close to the pickup and then pull it up and away. The meter will read some minimal voltage. The number doesn't matter, only the polarity. My meter is an old analog, and either needle moves on the scale (for positive), or it tries to move the wrong way and can't (negative). Make some note or marking that is meaningful to you re: this measurement.

Now do the same thing with your other pickup. When the needle moves the same direction for both pickups you know which wires to connect to get them wired "in phase" together.

Now, just for fun, try to touch the pole piece side (the side you'll see when it's installed) of one pickup against that of the other. If they stick, they're reverse magnetic polarity from one another. Opposites attract, right? This means you'll get happy humbucking when the two are connected.

Does that help?

[ChrisK]

Well, this is a difficult question in that there is not a positive or negative on a pickup. Pickups are an AC generator and generate waveforms that are comprised of sine waves.

Pickups do have phasing issues. If one pickup is electrically out of phase with another, the signal components that are common will cancel.

Phase is only relative to another pickup, and only other pickups within the same guitar. If only one pickup is in a guitar, phase is not of concern. If a guitar has more than one pickup, reversing the wires on all pickups will result in the guitar sounding exactly the same (phase is relative).


Now, many manufacturers do color code their pickups to make proper phasing easy when they are wired in the factory (and beyond). This is often called polarity, which is a DC term. However, phase is just a form of relative instantaneous polarity.

Unfortunately, there are no universal standards. Knowing the manufacturer of the pickup can help.

If you are installing this pickup in a guitar with other pickups and it sounds weak and "tinny" when selected with another pickup, just reverse the connections of the two wires (reverse the phase).

[ashcatlt]

That's what I'd call the hard way, seeing as it might require taking the thing apart, soldering, and putting it back together more than once. Of course, if you haven't got a meter, or need practice soldering...

It raises an interesting question, though. Does anybody care which way the speaker moves when you hit the strings? In the (audio) engineering circles in which I occassional run, there are some who claim there is a noticeable difference when it comes to the absolute phase of certain instruments.

According to this school of thought, the initial attack of something like a kick drum should push the speakers out, toward the listener. Also, I've heard that sometimes if a kick drum and bass instrument are not meshing well in a mix, flipping the phase on one of them can sometimes get them to "push together", and tighten up and/or punchify the low end.

I've always heard that absolute phase doesn't make any difference in guitar pickups. But what if you've got some metal group with a couple of drop tuned guitars, bass, and drums? Think it might make a difference the relative phase between the various instruments?

[d14099]

i should have been more specific, the pick ups are out of a 50/60's reissue strat, i was told japanese, the neck has red/white wires, the mid and bridge have white/black, i tried the screw driver trick and got the reading when i hook the meter up with positive to the white wire and negative to the black wire i get a negative reading on the meter, the same for the neck when negative is hooked to the red wire, so im assuming all the whites go to the switch and the red and the two blacks get grounded to the pots, the screw driver sticks to the neck and bridge pick ups and falls off the the mid pick up is that because it is reverse wound?? when i take another bride pick up it sticks to the installed bridge somewhat sticks to the mid and pushes away from, the neck pick up, does any of this make sense ?? the neck measures 5.90, the mid 5.96 and the bridge 6.06 ohms

[ashcatlt]

Again, doesn't really matter which one goes to the switch and which to ground, so long as all of the pickups are pushing the same direction at the same time. Sounds like what you've proposed will work okay.

Is your screwdriver magnetized?

The pickup you used to test with certainly is, and from what you describe there it sounds like your neck pickup is reverse magnetic polarity from the other two. In standard strat wiring, that's the one you'd prefer to have in the middle in order to get hum cancelling in the 2 and 4 positions.

In a "matched set" of pickups, you'll often find the lower resistance in the neck. All other things being equal, it would be expected to have a slightly quieter, slightly brighter output. Since it's not a matched set, all other things probably are not equal.