Fender MIM Jazz Bass Hum, Goes Away When I Crank Tone Control

[stevieb]

Tonight, I heard a hum when I plugged my MIM Fender Jazz bass into my bud's amp. The hum went away when I touched the metal plate the plug and knobs are mounted on, or turned the tone up (or was it down? It's late, I don't remember.)

Is it possible this is a simple thing to fix? My head hurts, I don't want to think about causes too much, tonight.

 

[Roguetitan]

try another wall outlet.
try a different instrument cable.

does the bass do that with other amps?

if so it could be that the electronics are not shielded very well.

 

[daav]

Mine was really noisy as well, until i replaced the pick ups with Fralins. that thing had the worst self-noise before.

Now it is dead quiet as long as both the volumes are turned up equally as much, if i turn one down a bit, it picks up some humm or fuzziness. Wierd.

Daav

 

[stevieb]

I did try another cable- same thing. We also had another bass there, and it did not hum thru that amp.

I really do not want to change the pups- happy enough with their tone otherwise, and I don't have or want to spend the money. If I shielded the cavities in the bass, might that help? Would it make me a bass dentist?? "Open wide!" Could I use aluminum foil?

 

[Tadpui]

Mine was really noisy as well, until i replaced the pick ups with Fralins. that thing had the worst self-noise before.

Now it is dead quiet as long as both the volumes are turned up equally as much, if i turn one down a bit, it picks up some humm or fuzziness. Wierd.

Daav

I think this is related to why the OP's bass hums as well. The two single-coil pickups are most likely wired 180 degrees out of phase with each other. When they're both turned up to equal volumes, the hum is output equally by both pickups. Since the hum is 180 degrees out of phase and at equal amplitude, it cancels itself out. But when you turn one pickup up louder than the other, the phase cancellation goes away.

Its probably related to why stevieb's bass hums when the tone pot is changed. it probably changes the output of that pickup in some way, making the phase cancellation go away.

 

[mrface2112]

i bet you've got a bad ground somewhere. although it could be the tone pot since it "went away" when you had it all the way up. i'd start by taking it to your guitar guitarshop and having its electronics checked out.


cheers,
wade

 

[Roguetitan]

I did try another cable- same thing. We also had another bass there, and it did not hum thru that amp.

I really do not want to change the pups- happy enough with their tone otherwise, and I don't have or want to spend the money. If I shielded the cavities in the bass, might that help? Would it make me a bass dentist?? "Open wide!" Could I use aluminum foil?

yes you can use aluminum foil and you may want to get some contact cleaner and spray the pots.