PUP phase determination [before install]

[robt57]

I had to share this little tidbit. Excuse me if it is redundant.

This is something i learned years ago and it occured to me while reading another post that it's something a lot of people here may benefit from. I read a lot of posts where someone installed a new pup(s) only to find after re-assembling the guitar that one of the pups is out of phase, giving that thin sound when 2 pups that are out of phase are combined. So i figured that since no one seems to have mentioned this trick i'd post it and hopefully save some people from having to dis-assemble thier fender a second time to rectify the problem.

For those not familiar with pup phase problems, this is something that happens when one of the pups is out of phase with the other(s) and causes a thin weak output when the pups are used together as in the #2 and #4 positions on a strat. The fix is to switch the leads on one of the pups in a 2 pup guitar, or on the offending pup in a 3 pup guitar.

But to avoid this from happening in the first place, you need to know whether the pups are in phase when you install them so that you won't have to open the guitar up again and rectify it. On a start it's especially helpfull because unlike a les paul for example you can't just pop off a cover and reverse a wire. To do this you need a meter set to read ohms.

With the pup not installed yet,(or installed, but with selector set to that pup only and volume knob on 10) set the meter to 20k ohms (unless it's an autoranging meter of course) and put the red probe to either the ground or hot lead and the black to the remaining lead. Doesn't really matter which goes to which, but the important thing is that you REMEMBER WHICH WENT TO WHICH AFTER YOU TEST IT !

Once they are attached and the meter is correctly reading the pup's resistance, take a screwdriver or other magnetic rod shaped object and very slowly lower it towards the pup's polepieces starting from about 8" away. As the screwdriver gets closer to the magnetic field you will notice the resistance reading on the meter begin to change. It will either go up or down. REMEMBER WHICH WAY IT WENT AND WHICH PROBE WAS ATTACHED TO THE HOT AND WHICH TO GROUND !!

So lets say for example the red probe was attached to the hot wire and black to the ground wire, and the meter reading went UP. Test all other pups and they should be wired the same. In other words, if pup #1 was tested as above example where the red probe was attached to the hot wire and the meter went up when you did the test, then attach the red probe to the next pup's hot and black probe to it's ground and do the same test. If it goes up, use the lead that was attached to the red probe as the hot. If it went down, reverse it. (use the wire that was attached to the black probe as the hot wire.

To simplify (hopefully !)make sure that the pups are all installed so that the wire you use as the hot wire makes the meter go the same way in the test on all the pups. Get it? If not i'll try to clarify it if you need me too. It's one of those things that is very simple but hard to explain.

http://fenderforum.com/forum.html?db..._number=333126