G&L MJ-4 audible noise - electronics or pickup problem?

[Cube Bass]

Hello,

I`d like to get some advice about this noise issue on my bass. There is some audible noise in high frequencies, only when a note is played, like it is somehow modulated by that note.. I boosted the treble to max for it to be more obvious to hear. It is not standard EQ setting, however once I know it is there it is distracting me even while the EQ is flat.
For those who don`t know - it is jazz style active bass with blend pot. This is the neck pickup soloed. The blend pot was dirty - the signal droped out on the other side (bridge solo). I thought that it should be the problem so cleaned it, but this noise is still present (listen to the audio).

So, could it be some faulty part in the active onboard preamp or maybe something with the neck pickup? Does anybody encountered this kind of problem on this particular bass or some similiar? The pickups are split humbuckers in shape of jazz style pups..

 

[Cube Bass]

Just trying to bump this one.

I got the advice elsewhere to change batteries and put on fresh strings first. It helped a bit but it is still present. With new strings I am taming treble anyway so not much of a problem now, but it is still itching me, because I know it is there.. Anyone ideas?

 

[One Way]

While you had the back cover off did you spray each control and the output jack with Deoxit?
I recently did this to my M-2500 which has a similar preamp and while inside noted the output jack needed tightening and several of the pots needed the attachment nuts snugged down.
Just providing maintenance ideas that might help.

 

[NG51]

I have an MJ-4, and was having some problems with distortion- I lowered the pickups and it helped. Maybe try that?

 

[Cube Bass]

I tried to spray it where I reached. Not exactly with Deoxit, didn't know the brand.. There is quite a bunch of types.
Will try the lowering of pickups although it seems to me they are low enough.

But maybe something with too much of signal going on should be the problem. Previously I had TI Power Bass strings, which may give too much output. The fresh ones are Dean Markley Blue Steel. But it seems odd to me to be restricted in choice of strings in terms of trying to get those with the lowest output possible.

Honestly I am beginning to toy with the idea of swapping the pickups or maybe the entire guts. Little afraid to end up with "different instrument" though.

 

[dwizum]

This kind of issue can be hard to nail down, it often becomes a "try things and see what happens" problem. It seems most commonly due to poor connections, or dirty parts.

I just fixed an instrument earlier today that had the same issue. Swapping to new pots made it go away. Perhaps they were dirty, or there were bad connections (a prior owner had done some soldering that looked pretty poor). For me, troubleshooting a part that costs about 87 cents is not worthwhile, unless there's some specific reason to retain the original pots - just replace them.

In other cases it's been a poor connection at the jack, or bad soldering at the jack. If cleaning doesn't help, you can bend the contacts on an open jack to get a better connection. If it's a barrel jack, just replace it.

And I've had a few cases where this sort of noise was from a dirty selector switch. Clean or replace.