Can someone diagnose what went wrong here? Slight wiring problem

phxlbrmpf · #1 06-11-2008, 05:26 AM

My band's guitar player recently added a bridge pickup into my fretless SX P copy (It's a humbucker for the bridge position made by a smallish German luthier, my guitar player offered to do it for me and I said yes as I'm really broke right now and having an experienced luthier do it would have cost me an arm and a leg). He said he had to redo the entire wiring as it was pretty crappy. He downloaded a J bass wiring schematic and wired the bass in Volume, volume, tone fashion.

Well, the bass works great except for a tiny fly in the ointment:

I noticed that even when the neck (P) pickup is rolled off, it's still not completely silent but still gives off a bit of a signal. I thought: "well, maybe the pot he used for it is faulty".

Yesterday I found out that the tone pot needs to be rolled off as well for the P pickup to be completely silent. The bridge pickup interacts with its volume pot without any problems.

Can someone figure out what the wiring mistake is based on my description or should I post a pic of the wiring? It's not a huge problem but it can be a bit annoying when recording. Lots of thanks in advance.

robert43 · #2 06-11-2008, 06:11 AM

Post pictures please

mjolnir · #3 06-11-2008, 06:52 AM

Wow... Yes, please definitely post pics.

I'd personally check the integrity of the pot first, considering I've had this same problem in the past and it turned out the little strip of resistive material was done wrong and left exposed metal where there should have been none.

phxlbrmpf · #4 06-11-2008, 07:02 AM

OK, I'll try to post some pics as soon as I can, it may take a while though, I've got some studying to do and a rehearsal tonight and getting the dang pickguard off to expose the wiring is always a bit of a pain.

mjolnir · #5 06-11-2008, 07:03 AM

Take your time, bro, we all know how it goes.

Rickett Customs · #6 06-11-2008, 07:06 AM

At least until the pics are posted, my vote is checking to ensure that it's grounded properly.

phxlbrmpf · #7 06-14-2008, 01:03 PM

Sorry 'bout the delay, I wonder if you can even tell anything from these pictures.

mongo2 · #8 06-14-2008, 06:51 PM

Quote:

Originally Posted by phxlbrmpf

Sorry 'bout the delay, I wonder if you can even tell anything from these pictures.

I can tell it's either a left-handed bass or the pictures are flipped.

It's hard to tell form the pics since there's a lot in the way of seeing the actual connections and the focus is way off on several shots, but what I can see looks like it's trying to be OK unless there's a bad component, ground, or solder joint.

**DougD** · #9 06-14-2008, 07:09 PM

It may not be the wiring, could be interference from lights. Some humbuckers can be a little noisy. Especially when you mix and match pickups.

Rickett Customs · #10 06-15-2008, 08:53 AM

Quote:

Originally Posted by DougD

Some humbuckers can be a little noisy. Especially when you mix and match pickups.

+1, he does have a point there.

Additionally, being a rigid perfectionist (one of my many character defects

), IMO, it looks to me that the wiring could have been re done a bit more neatly (to my eyes). Another thing you may want to try is: ground the back of both volume pots together, this may or may not make a difference for you, (although i'm not an electrical engineer).again, anyone correct me if i'm in error

And if all else, make sure it is not the pickup itself.