Jazz bass Pickups, if not out of phase, are they doing RWRP?

[samurai1993]

I've just finished the custom Ric-inspired wiring for my Jazz Bass, and it was all good ok. For a 1st completely self-made design, it's great that it worked at the first try.

But the problem is, I feel the pickups are running a little on the noisy side. At first I wired them out of phase (the sound was really thin) so I switched the leads on one of them - I don't remember if neck or bridge - and I had full sound, but also lots of EMI. Maybe because haven't shielded the cavity yet, or maybe because of some problem I'm testing it in a guitar amp but well, I'll keep testing.

I don't have problems with the wiring, I understand it pretty well, my question is, with proper Jazz Bass pickups (This are from a Geddy Lee), if I had them first out of phase, switching the leads in one of them is ALWAYS the correct way of doing it? It doesn't matter if I switch the neck or the bridge?

Thanks!

[SGD Lutherie]

Are they humming, or buzzing? The pickups in the GL should hum cancel.

If you are getting a lot of buzzing then you need to shield the bass.

Humbuckers, and RWRP only gets rid of hum. The high pitched buzzing is electrical field noise, and you need shielding to fix that.

[Bassamatic]

It doesn't matter which is switched - phasing is relative.

Shielding may help. Perhaps you have a long hot lead now that is very susceptible to noise pickup. I also find that some noise is location specific. My computer causes a lot of noise in my instruments, for example.

[Stealth]

Also, if you did swap the leads on one of the pickups, maybe the now-hot wire is actually tied to the pickup ground somewhere - that would certainly cause hum.

[valentine1]

sorry to hijack the thread everyone, but is this guide on 'shielding your bass' pretty much what the doctor ordered?

http://www.notreble.com/buzz/2011/09/20/the-buzz-killer-how-to-shield-your-bass/

i just purchased a geddy lee jazz bass (2008 CIJ) and i have noticed that there is both a hum and a bit of buzzing.

75% of it comes from my DI/preamp when OD is engaged (i'm still not sure why this is) but I was thinking about shielding the cavity this way before I start fiddling and replacing any pickups. is this a good guide to go by?

thanks.

[Stealth]

Yep, that's how it's done.

[walterw]

Also, it does matter which pickup is reversed; with fender-types, reversing the leads puts the hot end of the coil against the magnets, making them noisy when touched.

Both pickups should be wired black to ground.

[Stealth]

Walter, doesn't Fender insulate the magnets themselves? That's an oddity.

[SGD Lutherie]

Originally Posted by Stealth

Walter, doesn't Fender insulate the magnets themselves? That's an oddity.

No they don't. And even if they did, since the magnets are not grounded, having the start of the coil, which touches the magnets to ground is a good idea to reduce noise.

[samurai1993]

I'll took note, in fact, when I touch the magnets they hum...

I was playing a little and the RWRP seems to work. First soloing the neck pickup and then maxing both volume pots, I notice that the hum dissapears, so the noise I hear should be EMI from the non-shielded cavity. Also I'll remember to ground the magnets.

In the other hand, I'm pretty happy with the tone these pups give, they work very well with the bass (A GL maple neck with a custom made 70's spacing Jazz Bass, made of Patagonic Lenga). I'll post some clips and pics when I get rid of the buzz :P

[walterw]

Originally Posted by samurai1993

First soloing the neck pickup and then maxing both volume pots, I notice that the hum dissapears, so the noise I hear should be EMI from the non-shielded cavity.

nope, that's straight single-coil hum, which shielding doesn't really help that much.

shielding helps with that extra buzz you get when you let go of the strings.

[samurai1993]

Originally Posted by walterw

nope, that's straight single-coil hum, which shielding doesn't really help that much.

shielding helps with that extra buzz you get when you let go of the strings.

I'm starting to think that maybe the problem is in the pickups polarity, I'm gonna do some tests to check that.

If that results to be the problem, is there any guide on how to repolarize them? I'm going to need some neodymium, right?

[walterw]

huh?

just take a little screwdriver or something and touch it to the magnets to make sure they still have a strong pull.

if they do, and if the hum goes away when both pickups are full-up while the sound is still strong and full, your pickups are fine.