Whats the buzz about?

[Spacehog]

Ok, So I've had my '83 4003jg for nearly over ten years now. I'm noticing this buzzing coming from my bridge pickup, and when I put my hand on the hand rest it goes away. If I tap on the pickup surround, or the hand rest, it gets picked up in the amp. I know they buzz sometimes but how do I make it stop without sacrificing tone and volume?

[gshadoan]

Sounds like maybe the ground wire to the bridge is dodgy. Could be worth a look see.

[rickenbrother]

Or the ground wire to the bridge pickup surround could be the problem.

[gshadoan]

Or the ground wire to the bridge pickup surround could be the problem.

erm... that's what I ment

[phlemmy]

your bass is ruined. i should take it off of your hands.

[johnallg]

your bass is ruined. i should take it off of your hands.

Sean, are you saying you're a sucker for midish 80s 4003 basses?!

[Spacehog]

well I know the ground is where its supposed to be according to the schematics , so what should I do?

[gshadoan]

well I know the ground is where its supposed to be according to the schematics , so what should I do?

If its a 20+ year old bass, and presumably used in the real world, it might just need a good cleaning, de-oxing, contact filing. The solder might need a touch up. Smoke and sweat can lead to dirty or bad connections. Without the unit in my hands, no telling what is really wrong, just some ideas. It sounds like the ground is interminent. If you are comfortable with disassembling the treble pickup surround, then have at it. Plug it in, and try to reproduce the failure, muck with the wire, till you dial in on what exactly is going on. Or, take it to a local repair person. If the term oxidation is a mystrey to you, then you should probably take it to a shop.

Good luck.

[Spacehog]

according to the diagram of the pickup assembly the ground is sandwiched between the spring and the adusjtment screw. I never really though that would be a good place for it. Do you think maybe relocating the ground elsewhere would be a better idea? Like I said if I'm idle and not playing the bass buzzes a little. when I touch the handrest it stops, and when I play it stops. Also, would it help to shield the underside of the pickguard? I so where do I get the shielding from?

[phlemmy]

your bass is ruined. i should take it off of your hands.

Sean, are you saying you're a sucker for midish 80s 4003 basses?!

[rickenbrother]

according to the diagram of the pickup assembly the ground is sandwiched between the spring and the adjustment screw. I never really though that would be a good place for it. Do you think maybe relocating the ground elsewhere would be a better idea?

Actually it goes between the spring and the surround. To ground the surround, there's no better place.
You can get insulating foil from Carvin, but I doubt that insulating the pickguard would help buzzing. The best thing to minimize buzzing, is to make sure your 4003 is wired properly and that all the solder joints are good.

[Spacehog]

so whats holding the ground to the surround then? I mean I know the adjusting screw goes right through it, but whats to say it has constant contact with the surround?

[johnallg]

Nolan, the tension of the spring holds the ground eyelet against the surround to keep it grounded. Make sure the spring hasn't deformed and collapsed. Assembly should be screw through surround, ground eyelet on screw, spring on screw, screw through pickup.

[Spacehog]

Yeah thats pretty much how I have it.

[johnallg]

And the wire from the grounding eyelet is soldered to a pot body? Try an ohmmeter and measure resistance from the jackplate to the bridge, to the surround, and to the pot bodies. All should be almost zero ohms.