Vintage modified Jazz bass wiring problem

Hi all,

I bought a second hand VM jazz bass yesterday and took it jamming last night. I found that when the lead went a certain way there was that 'crackling' horrible noise and a loud humming. The kind of thing that happens when you have a dodgy lead. I switched leads to one I know works and still the same problem.

Then...

While we were playing a little later I started to hear a radio station coming through the amp (I thought I was losing my mind big time before I eventually told every body to shhhhh and they could hear it too!)

Iv removed the control plate to see if there were any broken connections but I cant see any.

I searched the forum and came across a .pdf showing how a VMJ should be wired and mine seems to be a little different.

I was hoping to tap into the TB brain trust and see if anybody could shed a little light on what might be the cause.

Iv taken pictures so hopefully they help diagnose the problem!






Any help would be most appreciated!

 

Bump

 

The tone pot works fine, I tried plugging the bass into an amp while leaving the control plate unscrewed, when it starts humming and crackling if i touch the pots with my fingers sometimes it stops but this result is not consistent.

If I wiggle the lead when it's plugged into the bass it can make the electrics start acting up (making the noises). Iv checked and there is really good contact with the input jack and the lead.

I'm totally stumped :-(

I will take better quality picks tomorrow to give a better view.

I wanted to gig this bass this weekend to test it out but it's too unpredictable.... Damn it :-(

 

Hi audioglen, thanks for all your help and suggestions, I replaced the output jack (thanks for the FYI ;-)) and checked the ground under the bridge. The ground under the bridge was just a wire and I can't see how it's not in full contact with the bridge when the bridge is on place.

The problem is still there though :-( there is no noise extra noise when I turn the volume and tone pots only when I move the cable in the output jack.

It's so weird...

Any other suggestions or should I bite the bullet and get new electronics?

 

There arent many techs near me and any that are wont be able to sort me out for a few weeks.
I think I will just buy a new wiring kit and rewire the bass. Do you think it could be anything to do with the pickups themselves because if they could be the problem I would probably buy new pickups that come with new electrics aswell?

Would any standard Jazz wiring kit do the trick or is there certain kits that I should steer clear from?

Thanks again for your help audioglenn its much appreciated!

 

As audioglenn said that is how any VMJ bass he has had has been wired and he hasnt had a problem but then again ill try anything!

Could you maybe tell me what I would wire to where? I am comfortable soldering and love a project ;-)

 

Thanks for your suggestions braud357, tomorrow I am going to resolder all the joints and replace any wires that I can. Hopefully that does the trick!

Hopkins, no the problem stays no matter what orientation/ combination I have any of the knobs. It only happens when I touch/ move the cable in the output jack. I thought replacing the output jack would solve the problem but it didnt make the slight bit of difference.

Iv never heard of a pickup becoming microphonic, is this a common isuue. From the looks of the bass it looks like it hasnt been kept in ideal conditions. all the screws holding the pickguard and control plate has discoloration/rust on them and the pole pieces on the pups also have the same.

I may have been a bit too eager when buying... lesson learned!

 

Not a bad idea and I'm keeping my eye open on the classifieds for something nice but I'm kinda stubborn and its getting to be one of those things where I really want to get to the bottom of.

As well as the electronics acting the goat I can't seem to get the action to where I'd like it to be. I know it's not a top end bass but Iv heard nothing but great things about them and that's why I bought it.

Iv set up all of my other basses great but this one seems to be giving me trouble on all fronts.

I do love the look of it though so I'm not giving up