Now I know why I always take it to a pro - pickup installation issue

rappa29 · #1 03-09-2009, 08:53 AM

Bass: MIM Precision Special, passive
Pickups: Stock P and single coil J bridge
The job: replace stock pickups with Fralin P (standard) and J split coil (+5%)

Another Saturday night and I ain't got nobody.... but I bought a soldering kit (Weller 25W) and decided to try do the 'the job' listed above last Sat night.

Started (and ultimately ended) with replacing the J. Successfully removed the old pickup without too much mess. Kind of successfully installed the new pickup, but it's an ugly solder job.

Did not get around to installing the Fralin P because I think I botched the J job.

The good...soloed, the pickup has greater output, no more hum and just plain sounds good!

The bad...together both pickups (stock P and Fralin J) sound like crap! There's significant volume drop and my lows are lost!

I'm not sure if it's a 'phase cancellation' issue because I don't think I'm losing volume of either pickup when both volume pots are up. I'm pretty sure both pickups are still making sound.

I'm pretty positive though, that I'm losing lows when both pickups are up. You can distinctly hear them disappear as I raise the volume of either pickup to match the other. I get the lows back when I lower the volume of either pickup, but not both (e.g. P is still full and J is lower or J is full on and P is lower). There's a distinct change in volume and lows when I do this, you can hear them come back at a specific point either pot hits in this situation. Weird....

There were 3 wires on the Fralin pickup. A black and a white the had ends that could be soldered and a black one that was already soldered onto the pickup to itself (assuming this wire connected the 2 coils. I soldered the white wire to the pot loop tab thing and the black wire to the back of the pot. This is the same way the stock pickup was soldered.

One thing to note, the black wire on the stock pickup was soldered to a ring shaped thing screwed to the bottom of the pickup cavity. Another black wire was solder from that and to the back up the pot. So the stock pickup had 2 black wires from pickup to ring from ring to pot vs only 1 from the Fralin. I assumed that was some type of ground and I removed it along with the stock pickup since I didn't think I needed a ground since the Fralin is a split coil, hum canceling pickup.

Anyhow, as usual, any advice is welcome, but I'll probably just end up taking it to a shop to redo my shoddy job and install the Fralin P. I don't know if I'm up to redoing myself and trying to do the P pickup without effin' it up.

Oh well...at least I took a shot at it and it wasn't my MIA Jazz or my Stingray!! LOL!

Craig_S · #2 03-09-2009, 09:42 AM

Swap the wires on one of the pickups. You should be good to go after that.

JustOpenYourMind · #3 03-09-2009, 09:51 AM

You are exactly describing how two out of phase pickups react with each other, simply swap the leads on one of the pickups.

rappa29 · #4 03-09-2009, 10:13 AM

So, staying with the J pickup, switch the leads so the white is soldered to back of the pot and the black is soldered to the pot tab thing?

Right now white goes to the pot tab and black is going to back of the pot.

I'll try that! I suspected they were out of phase, but the last time I had out of phase pickups (same configuration) I had slightly different symptoms.

Thanks!

John Wentzien · #5 03-09-2009, 10:21 AM

It probably won't be out of phase with BOTH of the new pickups installed..
Might want to install the P pickup instead of switching the leads on the new J.
(same amount of work)

rappa29 · #6 03-09-2009, 11:04 AM

Quote:

Originally Posted by John Wentzien

It probably won't be out of phase with BOTH of the new pickups installed..
Might want to install the P pickup instead of switching the leads on the new J.
(same amount of work)

Good point. I might as well take a shot at installing the new P as well....

Jefenator · #7 03-09-2009, 11:13 AM

I had the same thing happen, putting in a new Fralin P - didn't get along with the old J at all. (Lost 99% of the signal w/ both turned up.) I got back in, reversed the leads and... bingo!

In your case, I would probably just proceed with installing the second pickup. (And this time, check for phase issues before buttoning everything back up!)

Do a quick search for some tips on soldering - with the right tools, it's not that tough IME. (Someone should really make a "sticky" with the best guide.) Or farm it out... it's all good.

Good luck & good drummers.

TrooperFarva · #8 03-09-2009, 11:17 AM

Also

Quote:

Originally Posted by rappa29

I assumed that was some type of ground and I removed it along with the stock pickup since I didn't think I needed a ground since the Fralin is a split coil, hum canceling pickup.

That's wrong. You still need to connect the negative wire to ground.

rappa29 · #9 03-09-2009, 11:38 AM

Quote:

Originally Posted by TrooperFarva

Also
That's wrong. You still need to connect the negative wire to ground.

So I have to put that ring back in? Dang!
So the J pickup wiring should look like this?

J pickup black-->ring-->another black wire-->back of pot
J pickup white -->pot

Dang! Back to the drawing board.

The stock P pickup has that ring also.