Noisy electronis / pickups, help please!!!

[BassCrazi]

I have an Ibanez Prestige SR1005EFM with Bartolini pickup. The tone is awesome, however if I put the treble up I get a horrible osculating interference in the amp. The problem is worse if I increase the balance to the neck pickup. If I change my position/stance in relation to the amp, the noise either increases or decreases as well so there definitely seems to be interference from the pickup or electronics with the amp. I have tried different cables and amp and the problem persists. The real problem with this is that when I play at venues where the sound is setup by independent sound company (i.e. we don't use our own rig), the sound engineers complain about the noise, which has to be "e.q.ed" out at the desk. Any idea on how to combat this irritation?

[David Schwab]

OK, a few questions; when you say "osculating interference" what exactly does it sound like? Are you standing very close to the amp? Does it go away if you move farther from the amp?

[BassCrazi]

Hi David, thanks for the reply. To describe the noise exactly is a bit of a challenge... The only other time I have heard something similar is when I have brought a drill or fan near a stereo, you hear the interference of the electrical motor in the stereo. Oh yes, also in very old motor vehicles, if you switched on the wind shield wipers while the stereo was playing then you would hear the wiper motors' interference in the stereo. That is the best that I can describe it, I hope you have a better idea of what I mean... I am not sure if it totally disappears if I move really far away from the amp, I am usually within about 3 meters of it though and can still hear the noise. It is when I change my stance so that I am almost side-on (not directly facing toward or away from) to the amp that the noise quietens down quite a bit. However the scope of movement is small, i.e. two degrees either way from that position and the noise is back.

[David Schwab]

Did this problem just start, or was the bass always like this?

Right off hand I'd say it sounds like a shielding issue. Those pickups are supposed to be noise canceling, but it seems lie they are picking up something the way single coil pickups do.

I would check over all the ground connections, and make sure the shields from the pickups are still connected to ground. That might be the bare wire, if the pickups use 4-conductor cables.

I had one of those basses in my shop not long ago.. if I remember correctly, the bottom of the Bart pickups are made from copper clad circuit board material, so there should be a ground wire soldered to that, as well as the ground lug.

If all the grounds check out, and there isn't an issue with the pickup (is the bass new?), then I would try installing some grounded copper foil into the pickup's cavity and see if that helps. If the bass is new, you might want to see about having it checked out for a warranty repair.

If you don't turn the treble up on the bass, and turn it up on the amp, does it still make that noise? Originally I thought maybe the preamp was osculating, and I was going to suggest moving input and output wires away from each other, but since the noise goes away when you move, it's the pickups doing it.

Anyway, the pickups should be quiet. If all the grounds are good, there might be a fault in one of the pickups (sounds like the neck pickup is the problem).

You can get replacement Barts.. those might be the import Barts and not the real ones.

I also make very quiet replacements for those size pickups.

[BassCrazi]

Hi David, thanks for the info. What you are saying makes perfect sense. The bass is about a year old and as far as I can remember, the noise was there from the start. I only really noticed it when I got my SWR amp which is clearly more sensitive than my little Peavey. However once I noticed it and plugged back into the Peavey, I noticed it there as well, just not as pronounced. If I turn the treble down on the bass and up on the amp, the noise is definitely reduced. Thanks again David, I will check for grounding connections etc and if nothing appears to be amiss, then I'll take it in for repair. Either way I will post the outcome for interest sake.

Thanks again.
Cheers.

[BassCrazi]

Problem solved....!

Hey David, I took the neck pickup out of it's cavity and inspected the earthing cable. Alas, the soldering on this connection was disgusting. I re soldered it and now it's almost dead quite. Thanks for the tip.

Cheers

[David Schwab]