Weird (in)harmonic artifacts on new pickup

[Special B]

One of my guitar students just built a guitar from parts he bought online. He used a Duncan Jazz at the neck and a DiMarzio Super Distortion at the bridge. The issue is only with the Super Distortion. He and his dad did the wiring, and from what they told me about it (and from looking at their wiring diagram), I don't see how their wiring could cause this issue, though I didn't take the pickguard off and look at it myself yet.

 

The problem is that when the SD is heavily distorted, there are some very noticeable harmonic artifacts. It sounds almost like it is going through a ring modulator. The harmonic artifacts are very inharmonic/dissonant, so the sound is definitely not desirable and I haven't noticed it on other SDs I have used in the past. It is definitely not a case of any of us not being used to using a high-output harmonically rich humbucker.

 

The Jazz p/u sounds perfect, and there is nothing funny about how the SD sounds when clean. It is just at high gain (which is what he bought it for) that this ugly inharmonic sound is there.

 

We already ruled out magnet/string pull and fret buzz as the issue. We also tried multiple amps and distortion boxes. Tomorrow they are going to try bypassing the tone pot to see if that is the issue. Each p/u has its own pot, and they are just the cheap ones that came with the kit he bought, so could that be the issue?

 

Like I said, the best way I can describe it is like the inharmonic sound of running through a ring modulator. Anyone know what this can be? A defective pickup? Improper wiring? Crappy pots?

 

Thanks in advance.

[WRGKMC]

Sounds to me like you have a one of the coils wired out of phase.

This is a common problem when people use generic wiring configuration charts

or ones posted by manufacturers that are not for your specific pickups

 

Go to the Dimarzio site and get the color code charts for their pickups.

Pickup wiring color codes are different for each manufacturer.

Then you have to apply the Dimarzio color codes to whatever schematic you're using

Its possible they have something wired wrong and the two pickups signals are working against each other

instead of working together.

[Special B]

Thanks for the reply. I will find the wiring chart for the Super Dist. and forward it to them.

[Mr.Grumpy]

It doesn't sound like a coil phase or pickup wiring issue, especially if the pickup sounds normal through a clean amp. If you wire a humbucker with the coils out of phase, it will sound very weak, very trebly and thin. I think there may be something else rattling or resonating. I would check the pickup mounting springs...if it's possible you might try removing the springs and holding the pickups up with a piece of foam rubber underneath the pickup. (This only works with solid body guitars) Also check that there are no loose or rattling pieces on the bridge or tuning keys. Google "foam under guitar pickups" for more info..

[Special B]

Thanks for the reply. I didn't think it sounded like a wiring or phase issue either (since the pickup didn't sound weak at all), but they re-wired the pickup based on DiMarzio's chart and that seems to have fixed the problem. I also thought it could be one of the springs vibrating and told them about that possibility as well. I will hear the guitar again during their next guitar lesson, but for now it seems that re-wiring has fixed the issue.

 

Thanks to both of you.

[Richard Guy]

If the issue persist, try lowering the Bridge Pickup