Buzzy pickup. John East related.

[NancyJohnson]

At Christmastime, I installed a John East Uni Pre 3 knob into one of my Lulls.  To be honest, what with what's been going on in the outside world, I've not been doing that much playing, but a couple of weeks back I picked up the bass and was noodling.  During my little session, I noticed that while the neck pickup was fine, the bridge pickup was very buzzy when you touched it, although it was silent otherwise.

I popped John a quick email - to his credit he's been great - and the determination seems to be an earth/ground fault with the pickup.  I've problem-solved at length here, run the pickups in isolation, swapped the pickups around etc. every conceivable combinations and the evidence leads to the pickup, although the pickup was fine pre-installation.

Now then, does anyone know how to solve buzzy?  Can I run a bit of wire from anywhere to anywhere?

[Doctor J]

Are the pole pieces exposed at the bottom of the pickup? Run a strip of copper tape along the poles, solder a wire to it and earth the other end.

[mcnach]

1 hour ago, Doctor J said:

Are the pole pieces exposed at the bottom of the pickup? Run a strip of copper tape along the poles, solder a wire to it and earth the other end.

 

This.

Find a way to ground the polepieces and you'll be ok.

If that is complicated (magnets being in the way, or epoxy or whatever), a little clear nail varnish on the polepieces will fix that too, but I'd try grounding them in the first place.

[NancyJohnson]

Thanks for these.  John has been brilliant so far, we're still not fixed, but he's been great.  I have made a suggestion to him about how the pickup wires are connected and he's been positive about that, so maybe something might change on that front in a later iteration of the unit.

[NancyJohnson]

All solved.  Considering the complexity of the issue, we seemed to get it sorted.

Turns out a ground wire had come off one of the pickups.  I mean, you pay thousands for a bass, soldering fails...sigh.

[prowla]

I've got a J-Retro in one of my basses and it is really a great piece of kit - deep and authoritative bass.