blacktop p bass pickups humming

[zaviere]

ok guys, just bought a used blacktop p bass from a guy off craigslist. Pretty beat up (looks like he wore a bracelet with mini-hammers dangling from it on his picking hand ***) but figured as long as it sounds good. Bring it home and its humming pretty loud. Given that they're supposed to be hum"buckers", I figure they shouldnt be doing that. Kinda weird though. It quiets down when I touch metal like it should. But theres still this weird loud almost squeeling. Kinda like the pickups sound microphonic. It went away when I turned my tv off. But why is it only with this bass? I have two other p basses. One with the stock mim pickup and one with dimarzio model p's and they dont do this at all. I really wish there was a way to describe it. It also goes away when I roll the tone knob all the way off. But comes back as soon as I raise it up the slightest. I checked the ground wire underneath the bridge and it seems to be ok. Made sure it was touching the bridge when I screwed it back down.

Could it be a bad tone knob? I tried spraying contact cleaner in there but it didnt help. Also the jerk failed to mention that he probably spilled soda on it. When I was unscrewing the pickguard I saw that it was sticky underneath the screws. Could it have messed with the pickups?

Another side note, could be nothing. But when I touch the pole pieces, only the top rows buzz (view as if the guitar was on a stand).

any help would really be appreciated. I'd hate to take it to a tech and pay to have him tell me the pickups are bad or something cause I can replace them myself. Hate to cause this was supposed to be the beater rock star bass. thanks guys

[llldino]

You said it went away when the TV was off? Does this mean that you only hear the noise when you're around your TV? Try playing in other parts of your room/house and see if it only happens around TVs. Fluorescent lights/Cpus/Tvs all produce E-fields that can mess with the sound of a pickup.

If the sound doesn't happen around other electronics, you might have a bad ground connection. You can check the connections with a multimeter.

[Stone Soup]

My basses make a wierd high pitched sound when I'm in too close to my laptop.

[zaviere]

well its only when I had a high gain setting on my pedal. BUT it doesnt do it with my other basses. only this one. And yes it went away to some degree when the tv was offbut you can still kinda make out that its still there. I really love the way this thing sounds by the way. Very deep and punchy so I really wanna get this straightened out. With the multimeter. I'm new to this kinda. I have one but what do I set it to? and connect the ground to what? anything metal? but connect the red wire to what? I apologize for my newbness. but yeah even now when I close my laptop and it goes into sleep mode it quiets down a bit. I know things like this will cause weird sounds and stuff but I thought these things were supposed to be whisper quiet. Maybe I'm thinking too much of it. Just let me know :P but yeah its really annoying to think that as soon as I kick in a little gain its gonna scream back at me. what about if I hit the stage and all the lights n stuff. It'll prolly cause all kinds of noise. I thought that was mostly with single coils.

[zaviere]

@stone soup. yeah I'll admit my guitars are super noisy but I alwasy figured well they're fenders. single coils = noise. but even my other basses are nowhere near this noisy

[JoeWPgh]

Sounds like a shielding issue to me.

[zaviere]

k hopefully the attachment works. but i attached a sound clip of the bass. I'm using a zoom b3 with just like a rat preset to demonstrate the sound. Again, my other basses dont make a sound anywhere near that rowdy.

In the clip (sitting in front of my laptop and the b3 on the desk. and the tv to my left about 5 -6 feet away)

First with the tv on
then I turn the tv off
then last I roll off the tone knob completely down.

[zaviere]

Bump? Is it really just shielding even tho the black shielding paint looks fine? So does the foil tape on the pickguard.

[zaviere]

last bump. I swear