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Jbass pick leads missing!

K

Karl Kaminski

Supporting Member
Aug 26, 2008
2,785
3,160
NYC
#1
HI all,
I just got a set of original Jbass pickups (stamp 18 35 73) BUT there were no leads (black/white wires) attached to the bobbin
Can someone tell me the proper wiring layout?
After some searching I've found pics on the net of...

Neck PU:
white-top (toward the neck-side)
black-bottom (toward the bridge-side)

Bridge PU:
white-top
black-bottom

<<OR>>

Neck PU:
black-top
white-bottom

Bridge PU:
white-top
black-bottom

I guess my main question(s) is should the pup be wired the same? and does it matter which is hot/common?
Thanks
Chapito
 
#2
I'd be more worried about how I was going to put leads on the pickups. :)

That said, it doesn't really matter which is hot/common, or which way the pickup is oriented. What will probably happen is that you will get the pickup leads wired out of phase - which leads to note cancellation/funky phasing sound. When this happens, you need to reverse where the leads are connected to the pots on ONE of the pickups.
 
#3
Thanks Slyjoe.
Do you have any suggestions for soldering the leads?
I just assumed standard cloth wire, rosin-core silver solder, with low wattage iron.
(I'm open to suggestions as the winding looks very delicate)
 
#5
slyjoe said:
The pickups I have looked at don't solder directly to the winding wire - the windings are terminated on metal posts that the leads are connected to.

Do the windings come out with bare wire?
Click to expand...

The winding comes out to (2) holes on the end of the bobbin
where is some old solder remaining.

I'm hoping its as easy as re-soldering to those contact points.
 
#6
That should be where the windings come out, and soldering to those should be ok. Just remember there is a 50/50 chance the two pickups will be out of phase. What I would do (if the pickups are the same) is solder them both the same; i.e., put them both so the holes are on the right or left, then put the same colored wire on the top of each. Likewise for the other wire.

You said they were a set, so it's likely just by wiring them the same you won't have the phase issue I mentioned.
 
#7
Ahhh , good point slyjoe
They both have the same fender date stamped on them so, logic would have it that they 'll be wound the same. Cool!
I'll give it a try and post results later this week

MUch thanks again!
Chapito
 
#8
Slkyjoe's got it dead on.

When re-attaching the wires, I think the important thing is to have the pickup lead pre-tinned and have the iron hot enough to do it's work fast. The longer the tip is in contact, the more opportuity there is for you to slip. You have to balance that with the bobbin's capacity to absorb the heat of course. having the pickup mounted in a vise or otherwise held down helps a lot.

J pickup set's are somewhat notorius for phase. For true single coils pickups it's completely a non-issue - you wire them up, listen and if it's whackekd - flip one set of wires.
 
#9
Thanks 4mal

I'm not much of an electronics guy but, I feel better about replacing (installing) the leads now. It seems simple enough.

Does anyone know if I can use a multi-meter (or other tester) to test the pickup before install? -to check my solder job etc.

I guess just installing them would be a test in itself.
But if you know of a method, please leave details...

Thanks
 
#10
Set your multimeter to measure resistance. I don't know off the top of my head what the DC resistance should be for these pickups, but probably in the 5-15K range.

Solder the leads on first, and use the multimeter on the leads - that will tell you if you hit the right solder point.
 
#11
I'm not sure if this is the same but I seem to remember seeing something on the Fralin or Nordstrand sites about 8.5k windings.

Do they mean the # of windings or the resistance?
Or is that the same thing?
 
#12
I might be inclined to check before and after. First make sure that the pickup has continuity, then after to make sure it still has continuty - if they don't have continuity first - there isn't muich point in soldering the leads on. If that were the case, my next step would be Pete Biloft at Invalid Link Removed Pete is my pickup supplier, rebuilder of choice. He does some really special stuff.
 
#13
The reason I would probably just put the leads on first is twofold:
1. You aren't mucking around those tiny winding wires with probes.
2. You can't tell if the solder joint at the end of the pickup is cold.

But that's just me. Probably 6 of one half dozen of the other :)
 
#17
Slyjoe - yep - given the number of times I've done this sort of thing. I'm realy comfortable and I go so sllooowwww, really, really slow and deliberate. If I have real questions, I put the thing under a lit magnifying glass and give it a good look close up. Even with the cold solder I would expect to get continuity. Resistance I'm not so worried about - I just want to know that the coil is intact before I mess with it.
 
#19
using a Craftsmen AutoRanging Digi Multimeter (82029)

Neck:
Continuity [OL.]
Resistance [6.12K]

Bridge:
Continuity [OL.]
Resistance [7.5K]

To the knowledgable-ones, do these numbers fly?
I got no reading with the continuity test - just the opening [OL.] screen
I have no idea if thats good or bad.

But I guess the pups are ok since I got a resistance reading from the posts (solder points). Thoughts?

Should the resistance be the same for both pups?
Can I correct it if they need to be the same? (or simply rewind via a pro?)
 
#20
OL means no continuity. Which doesn't make a lot of sense with those resistance readings.

The resistance readings look like they are probably ok. I wouldn't worry about them being a little bit different - one pickup MAY be slightly hotter than the other one.

I personally would solder them up and plug them in. See how they sound before you start thinking about rewinding.
 

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