Originally Posted by bass dan
Just so I'm clear about this. These pickups do hum when you touch the pole peices. This is the way they are made. Unless you sheild the cavity you will always have some hum if you touch the pole peices.
I may have them installed correctly? I duplicated the way the Fralins were installed.
As I mentioned last time, if the start of the coil (which touches the magnets) is connected to hot, you will hear hum when you touch the magnets. If the start of the coil is to ground, you wont. With a P bass you will have one that does not hum, and one that does.
You have to look at it as the two coils in series. Let's go left to right; with the start of the coil on the left, and the finish on the right.
On the start end you have ground, then the start of a coil, then the finish of that coil goes to the start of another coil, and then the finish of the second coil goes to the volume pot.
If the first coil has it's start to ground, the magnets will not hum when you touch them, but the second coil will no matter what. This is because the first coil's magnet's are near the ground side of the coil, and the noise is shunted to ground. The second coil however has its poles in the middle of what is like one big coil, so touching them will always make noise.
If the start of the first coil is to hot, then its magnets will also hum. That's what you have going on. So if you flip the polarity of the pickup, the start of one of those coils should now be at ground, and that coil should stop humming when you touch the magnets. But only one one coil. So that should be the one under the E/A, being that most people rest their thumb on it.
Now there can be a situation where the two coils were wound in the same direction, and then wired up start to start. That will hum no matter what you do, but that's not the normal way to wind a P pickup.
Incidentally, Fender winds the single coil pickups so the start (black wire) is ground to prevent the humming. On the Fender Mustang, you are able to switch the polarity of the pickups. because of that Fender used closed covers so that you could not touch the poles, and wouldn't get the hum.
Ideally the magnets should be grounded. That will stop the problem.