trouble shooting question.

[kevinT]

Have a customer who bought one of my neck pickups. He installed it in an SG. Both the neck and bridge are working fine, however, when he puts it in the middle postion it drastically looses power. The polarity is correct and according to my LCR and the meter i use for DCR, everything seems to be working properly.

I am thinking that it is the switch or that a wire was touching one of the legs of the pot which is wasn't supposed to..

Does anyone else have any ideas what it could be?

[NightWinder]

....

Have a customer who bought one of my neck pickups. He installed it in an SG. Both the neck and bridge are working fine, however, when he puts it in the middle postion it drastically looses power. The polarity is correct and according to my LCR and the meter i use for DCR, everything seems to be working properly.

I am thinking that it is the switch or that a wire was touching one of the legs of the pot which is wasn't supposed to..

Does anyone else have any ideas what it could be?

I'd look in the switch for a stray wire barely touching something other than the appropriate tag. Only occuring in the middle position..There could be a short in the wire from the switch???

[GlennW]

I'd guess both pickups have their own volume knobs and that the volume drop occurs when both knobs are on 10. If so, there's an explanation for that, but I don't know it. Usually backing off one volume knob a little will make it louder. I doubt if it has anything to do with the pickups.

[kevinT]

I am very careful about wiring up the leads to the hookup wire (BTW it is 4 conductor) could hooking up the wrong wires do this.... He says that it has a volume drop and a phase effect kick in when it is in the middle position. I had this happen once but i couldn't figure it out for the life of me after checking everything a couple times.

Each pickup works fine on its own.

[kevinT]

I'd look in the switch for a stray wire barely touching something other than the appropriate tag. Only occuring in the middle position..There could be a short in the wire from the switch???

that is what i was thinking. He said that he had all the electronics changed over recently.

[David Schwab]

Are they out of phase? That's what it sounds like to me. Since he's also using an existing pickup, I think that's the issue. Did he say they get real thin sounding?

[SK66]

I'm guessing winding direction (electrical phase). I would suspect any "shorting" to ground by a switch (other than some kinda "barely short) would kill things, unless it was grounding thru a resistor or something...
This is simple enough to test, just wire them in with hot/grounds reversed for one. If these are humbuckers with vintage gibson type leads, the pickup may(will) become very noisy but it won't have the "phase quiet" if that was the problem.

[SK66]

I'd guess both pickups have their own volume knobs and that the volume drop occurs when both knobs are on 10. If so, there's an explanation for that, but I don't know it. Usually backing off one volume knob a little will make it louder. I doubt if it has anything to do with the pickups.

This is due to the fact that with the vintage gibson wiring, at full volumes the pickups are 100% parallel and load each other. Slightly reducing the volume of either control creates a resistance to the parallel wiring and prevents the pickups from loading themselves.
This can be prevented by wiring a small resistor in series to each volume pot.
However, this would not be a "new problem" occurring with new pickups.

[David Schwab]

This is due to the fact that with the vintage gibson wiring, at full volumes the pickups are 100% parallel and load each other. Slightly reducing the volume of either control creates a resistance to the parallel wiring and prevents the pickups from loading themselves.
This can be prevented by wiring a small resistor in series to each volume pot.
However, this would not be a "new problem" occurring with new pickups.

That's true of course, but if the customer is saying he's "drastically" loosing output, and this seems like an issue to him, as compared to how the guitar was with the original pickups, then it's a phase issue.

You always have a chance of a new pickup being out a phase with existing pickups.

It could be winding direction, it cold be the magnet, and it could be the electrical connection. That's why I always use 4 conductor wiring... makes it easy to reverse the electrical polarity. Vintage style coax is a pain... but then flipping the magnet around will also fix it.