New pickups, with hum

[Music_Jag]

I just replaced my pickups in my CIJ Fender Jaguar. I put Fender noiseless pickups in them. Now I'm getting a hum when I'm not touching the strings. I figured its probably a grounding issue but not sure where to start to fix it. All advice would be great. Thanks

 

[Music_Jag]

Please, any help would be awesome.

 

[BassistFreak416]

grounding

 

[bassmodder]

Did you try shielding the control cavity with foil? I find that it helps some but depending on the pickups, they might just hum...

Also, black wire grounded to jack and white going to the "hot" on the jack?

 

[RickenBoogie]

Yup, recheck that everything's properly grounded.

 

[FunkMetalBass]

Sounds like you don't have the bridge properly grounded.

Also, make sure that all of the pots are grounded to each other.

 

[HeyyyyyJoe]

I'm actually having the same problem with my modified Jazz Bass. I get a hum when I'm not touching any strings. I replaced the stock pickups with Dimarzio ultra jazzes. The White and Black ground wires are not touching anything, should I just solder them to any of the volume pots to ground them and stop the hum?

I've already shielded the cavities and the pickguard.

 

[walterw]

I replaced the stock pickups with Dimarzio ultra jazzes. The White and Black ground wires are not touching anything, should I just solder them to any of the volume pots to ground them and stop the hum?

:scowl:
does no one read the instructions that come with their pickups?

those black and white wires get soldered to each other, then isolated from everything else with tape or heat-shrink.

grounding them would just shut off half of the pickup.

as for the noise when not touching the strings, it's normal. shielding should reduce the extra background noise, if the shielding is grounded. if the shielding is not grounded, it will add noise instead of reducing it. i would check for this first.

 

[HeyyyyyJoe]

:scowl:
does no one read the instructions that come with their pickups?

those black and white wires get soldered to each other, then isolated from everything else with tape or heat-shrink.

grounding them would just shut off half of the pickup.

as for the noise when not touching the strings, it's normal. shielding should reduce the extra background noise, if the shielding is grounded. if the shielding is not grounded, it will add noise instead of reducing it. i would check for this first.

Actually, that's exactly what I did. They are soldered together and have electric tape around them. But how do I ground the shielding properly?

 

[Music_Jag]

I didn't change any of the wiring, i just cut and spliced the old wire and attached it to the new wire, matching white-white, black-black, and yellow-yellow. All my splices were soldered and covered with shrink tubes.

 

[bassbenj]

I'm actually having the same problem with my modified Jazz Bass. I get a hum when I'm not touching any strings. I replaced the stock pickups with Dimarzio ultra jazzes. The White and Black ground wires are not touching anything, should I just solder them to any of the volume pots to ground them and stop the hum?

I've already shielded the cavities and the pickguard.

White and black wires are NOT ground wires. They are the connection between two coils. They should be soldered together and not touch ANYTHING (tape or shrinktube over the connetion!)

Whenever you get a hum that goes away when you touch the strings (or any other ground like the jack body or metal knobs) that means your shielding isn't working. Since you've shielded the cavities that has to mean that somehow the conductive shielding isn't grounded for some reason. All shielding should be grounded to the body of the jack (or it's equivalent if that is nearby such as when there is a wire from the jack BODY (not "ring" which is battery ground for active basses!) to say the backs of the pots. Check your shield connections with an ohm meter. Make sure the shields under the pickups have been connected to the rest of the cavity shield too! Make sure you've got a good contact to cavity covers and the pickguard foil. I like to run a wire from the cavity shield up around a nearby screw hole where the guard foil covers that screw hole. That way the pick guard screw mashes the foil into the wire to make good contact. Happy hunting.

 

[walterw]

...how do I ground the shielding properly?

Whenever you get a hum that goes away when you touch the strings (or any other ground like the jack body or metal knobs) that means your shielding isn't working. Since you've shielded the cavities that has to mean that somehow the conductive shielding isn't grounded for some reason.

what benj said.

another trick that fender uses to ground their shielding paint is to run a 3/8" long wood screw right into the side of the control cavity (piercing the regular paint and going into the graphite paint underneath it), and run a wire from that screw to ground.

when all is said and done, you might still get some noise when lifting your hands off the bass, but good shielding should at least reduce the effect.