Question on P-Bass pickup

[cynical1]

I have just acquired what I believe to be an original epoxy potted Bill Lawrence (pre-split) EB-60 p-bass pickup. But considering it's been over 25 years since I've seen one, the wiring on the back has me puzzled.

Here's the pickup from the front:



...and here it is from the back:



You'll notice that there is a white wire coming out of the left pickup, and a black wire coming out of the right. And there's the white wire tying the two halves together. This all looks pretty typical. It meters at 10.15K from the black and white leads coming from inside the pickup.

Then there's the red and black wire soldered to the baseplate on the left pickup. Here's a close-up:



And it looks like there may have been wires soldered to the right side as well, but they have long since gone the way of all things. Again, here's a close-up of the right baseplate:



Considering I had no plans of doing anything fancy with this pickup, I assumed I only needed the black and white leads and I could just cut and heat shrink tube off the red and black wires...

Then I started thinking...maybe I should seek confirmation and a valid second opinion first...so...

Does anyone remember these pickups from years back? Is the consensus with cutting and taping off the red and black wires from the left baseplate...or should I try and figure out what's supposed to go on the right baseplate before attempting anything else?

I fired off an e-mail to Wilde pickups hoping this is an older Lawrence and he might remember it and offer some insight. In the meantime, anyone out there with an insight is more then welcome to chime in.

Happy Trails

Cynical One

[JohnH]

I'm only guessing here. Just a few thoughts on things to check:

If you connect to amp between the black and white wires from inside the pup (ie the ones with 10.15k between them), and tap the poles of the two pup halves, are both halves of the pup active (hoping so)?

Are either of those two wires also connected to the case? Im guessing not, but if one is, then you know which coil wire has to go to ground.

If as above, then Im guessing the black wire that is soldered to the case of one half wants to be resoldered to the case of the other half, for shielding, then you have the red wire to go to ground to shieild everything, and the black and white coil wires.

cheers

John

[cynical1]

John -

Good point. I found something in the Interweb about a red wire going to ground...but nothing about a mysterious black wire.

And both halves tap test just fine. I should have mentioned that before....getting old...but not as old as SG...

I remember a friend of mine having these in his bass back in the early 80's and it just thundered. The bass this is going into has two jazz type single coils and this will help bottom it out quite nicely.

I haven't heard back from Wilde yet, but it does take a few days.

Thanks again, John.

Happy Trails -

Cynical One

[newey]

I'm guessing, too- never saw a pair of those even back in the day. But I wasn't a bass guy so I wasn't paying much attention to them.

I'm guessing the wires to the baseplate are not original, and that they were added later by someone who thought things might get quieter. I say this because:

• The wires coming out from under the covers must carry signal; these therefore figure to be shields.
  
  
• Red is not a usual wire color for a shield/ground. Looks like someone used what was around.
  
  
• Insulated wire is not needed and a manufacturer would save the cost.
  
  
• Assuming the upper coil once also had wires attached to its backside, it doesn't seem to be soldered in the exact same spot as the lower coil; production would be more uniform.
  

OTOH, things could have been done sloppier way back when, too. Again, I'm guessing.

[sumgai]

c1,

All is as John has suggested. newey's guesswork was properly qualifed as such.

These were built by hand, as are all of Willy Stitch's pickups. (Lawrence pickups, however, are usually made off-shore, by machine.) Therefore the solder spot isn't likely to be in the same spot.

Insulation is deemed necessary because of where the wires go within the overall scheme of things, which is to say the pup maker doesn't know where his/her product will end up, so it's best to play it safe. Besides, there was an extra 1000' spool laying around the shop, and really, who cares if it's red instead of green, right?

Denoting that a wire coming out of a coil must be a shield has no foundation. All we can gather is that it's connected to one end of a coil, and that's only because we have a meter reading smaller than infinity (open loop). Now if there were a meter reading between said wires and the baseplate, that'd be a different story.

I'd re-attach the "mysterious" black lead to the other pup's base plate for grounding/shielding purposes, and install the things.

HTH




sumgai

[roadtonever]

It's not uncommon for Bill's pickups have two ground wires. I'm not 100% sure but I have a vague memory of a post at the Wilde-gate stating one wire goes to the pot, the other to common ground. It may be a given but it should work as well to connect both wires to either ground point.

[cynical1]

May 6, 2011 0:56:16 GMT -5 roadtonever said:

I'm not 100% sure but I have a vague memory of a post at the Wilde-gate stating one wire goes to the pot, the other to common ground.

I'll need to start haunting there. The closest I found to an answer was the red wire going to ground. My senior moment came in trying to figure out what to do with the black wire...and what was soldered to the right side back plate. John's answer seems the most logical to me.

I did get this back last night from Wilde pickups:

"Hi! Let me ask Bill about the wiring here. I'll be back in touch.

Sincerely,

Becky"

And they've been like that for years. I remember actually talking to Bill years ago at a NAMM show. Scores of people with money (read as non-musicians) and he spent time with me to discuss bass pickups. They broke the mold after him.

Happy Trails

Cynical One