Crackling when raising pole pieces on DiMarzio* Model P

[LiptonJigglers]

I have the original stock 1980s DiMarzio P/J set in both my Maton JB4's.

The poles can get rusty on these pickups and im wondering if this rust may have extend internally and broke free upon adjusting them, causing interference..

It's been my experience with these pickups, pole adjustment doesn't really add any more volume to the already rather hot pickups, but provides slight tonal adjustments..

 

[iiipopes]

I have the original stock 1980s DiMarzio P/J set in both my Maton JB4's.

The poles can get rusty on these pickups and im wondering if this rust may have extend internally and broke free upon adjusting them, causing interference..

It's been my experience with these pickups, pole adjustment doesn't really add any more volume to the already rather hot pickups, but provides slight tonal adjustments..

Aw, beat me to it! This ^

 

[Riff Ranger]

I have the original stock 1980s DiMarzio P/J set in both my Maton JB4's.

The poles can get rusty on these pickups and im wondering if this rust may have extend internally and broke free upon adjusting them, causing interference..

It's been my experience with these pickups, pole adjustment doesn't really add any more volume to the already rather hot pickups, but provides slight tonal adjustments..

Aw, beat me to it! This ^

I had a hunch that adjusting the pole pieces might have dislodged something. I suspect they had never seen adjustment in their nearly-40-year existence.

I have had no issues since lowering the pole pieces back to their previous positions flush with the top of the housing. Does that tell us anything?

Thank you to everyone who has chimed in thus far, particularly for your patience as I’ve suddenly found myself working with a dedicated bandmate for the first time in ages!

 

[sunbeast]

The poles on these are run through fully enclosed plastic in the bobbin, so no fear of snagging the pickup windings when moving them and minimal fear of dislodging crud into the coil itself. The poles do run between the magnets on the bottom (threaded into individual anchors), and often time the epoxy blobs that hold the magnets in place on older Model Ps is quite dried out leaving the magnets somewhat loose. If the magnets are indeed loose then its possible that moving the poles out might have loosened the little sandwich of magnets and polepiece anchors and caused the poles or their anchors to vibrate against the magnets while playing which could potentially create noise like this. I'd recommend pulling the pickup out and seeing how easy it is to move the magnets or if you see any looseness in the pole anchors when the poles are raised as you had them. most likely either issue could be fixed easily with a little super glue or epoxy

 

[Riff Ranger]

The poles on these are run through fully enclosed plastic in the bobbin, so no fear of snagging the pickup windings when moving them and minimal fear of dislodging crud into the coil itself. The poles do run between the magnets on the bottom (threaded into individual anchors), and often time the epoxy blobs that hold the magnets in place on older Model Ps is quite dried out leaving the magnets somewhat loose. If the magnets are indeed loose then its possible that moving the poles out might have loosened the little sandwich of magnets and polepiece anchors and caused the poles or their anchors to vibrate against the magnets while playing which could potentially create noise like this. I'd recommend pulling the pickup out and seeing how easy it is to move the magnets or if you see any looseness in the pole anchors when the poles are raised as you had them. most likely either issue could be fixed easily with a little super glue or epoxy

Here’s what it looked like when I royally botched the toothpick trick trying to un-strip the screw holes a bit over a year ago (follow that link and you’ll understand why I remain reluctant to go this far under the hood to this day) (and obviously I’ve since had a professional repair this). Can anyone tell from this image whether I have a true DiMarzio or a clone? I can’t tell from listening

 

[Riff Ranger]

While it means the mystery will remain unsolved, it brings me joy to report that I finally made time to try raising the pole pieces again today, which failed to reproduce the bizarre crackling but succeeded in eliminating any noticeable gap in output between this bass and the active basses whose outputs I’ve effectively equalized through painstaking adjustments on their preamps. I MAY NEVER TWEAK KNOBS AGAIN, BWAHAHA!

I would guess the crackling came from the static issue and/or dislodging crud, which somehow all worked itself out as I regularly picked up and played and put down this bass over the last several days.

Thanks again for your thoughtful replies. I kinda wish I had a clear answer, but I’m mostly glad I don’t!

 

[StayLow]

I MAY NEVER TWEAK KNOBS AGAIN, BWAHAHA!

Congrats! That’s a reasonable solution.

Some smacks or a re & re resolves a surprising amount of problems.

 

[Riff Ranger]

Of possible interest to those kind enough to take an interest in any of this: I bumped up the drive on my Para Driver and padded my interface by -10db and now this passive bass with the Model P (or faithful clone) gets 1–2db louder than my active basses so I’ve lowered the pole pieces and pickups a little bit and everything seems close enough