It's so much fun and so much cheaper.

[bloke]

I've done several things cosmetically to my pawn shop purchased five string Fender jazz bass.
I swapped out the pickguard which cost about 10 bucks (simply for the sake of the color preference), Monday I'll order a different set of tuners (5) - simply because I don't like the style and look of the originals - and that will cost less than $50. I swapped out a couple of other things which cost about $20 for those things total. I also bought a set of strings (overdue, and the ones on there were probably the originals) that cost under $40.

So far that will be $120 or so.

Thinking further, I did just buy some carbon paint to create a Faraday cage around the electronics (many of you know what this, is but others can Google it) to cut down on external electronic interference noise. That was about $15. (This stuff can be made at home, but I'd rather repair instruments for money than mix this stuff up and use up my time that way.) ...
...and (a lot more expensive) I might put some "humbucking" (dual coil) pickups on this instrument that I might possibly (??) give myself for Christmas. Traditional Fender pickups are single coil, whereby - even if all the other electronic interference is done away with via a Faraday cage - one still might detect a little bit of 60 cycle hum making it to the speakers in the amplifier. Dual coil pickups cut this out. Two like this (whereby an aftermarket highly thought of company manages to jam dual coil pickups into the small Fender sized plastic shells) cost around $300. That would be a considerable expense, but (comparatively speaking) a fairly cheap visit to a brass repair shop and not even the cost of parts for a typical brass instrument customization. That said, if the Faraday cage eliminates most all the interference noise (which can even be caused by having the potentiometers turned to different positions) and the 60 cycle hum is nearly imperceptible, I might well forgo this. (I'm certainly not some superstar bass player...) Even in a recording studio, it's really easy - with modern technology - to digitally eliminate anything that is 60 cycles from a recording.
I've got the string action low, and there aren't any fret buzzes.

[tubatodd]

I would recommend copper tape. Any bass that I have removed installed/reinstalled pickups in, I like the control cavity and pickup cavity with copper tape. I also run a small wire linking the 2 copper cavities. Then I add copper tape to the BACK of the pickguard near the pickup route. Also make sure you gave a good ground from the electronics and there is a good ground from the control cavity to the underside of the bridge.

That being said, jazz pickups (as you know) will have a hum if either pickup is soloed. They SHOULD be hum-canceling with both pickups on.

[bloke]

I'm going with the carbon paint first and if that doesn't work well enough I've got conductive-adhesive-backed copper foil here.
I'm probably going around the corner to the top to make good contact with the covers (pick guards) of those cavities to increase the likelihood of good contact with the tops of the Faraday cages with the sides and bottoms.

There are some passive "Apollo" SD humbucking pickups whereby they manage to jam dual coil into the skinny fender single coil plastic pickup plastic frames.

The particular ones that I think I would like to try are about $150 apiece for five string. I'm putting off that until I give it a lot of thought. At that point (considering the bargain I got on the five string) the overall cost would start approaching the area whereby I would really be upset were it's stolen.

It's not that this bass doesn't deserve those pickups. It's not as if it were a Glarry or something. Again, all this stuff costs peanuts compared to upgrades and custom stuff on tubas.

[iiipopes]

You will receive twenty million recommendations about pickups if you choose to change them. Having been this route many times with friends' basses, as well as choosing pickups for my own basses, it is my opinion that if you do not want to go EMG actives and rout a battery cavity, that the best overall noiseless J-bass humbuckers are the Seymour Duncan Apollos. They were designed by Kevin Beller, a Jazz bass player, and with his engineering degree Seymour Duncan's head of engineering and research and development. To my ears they are the closest in tone and output to "real" Jazz bass single-coil pickups, when that is the vibe you want. There are many other end-to-end and stack pickups, but these are the closest. I dare say that if you turn the mid control down on the amp a half-notch, and/or turn up the treble and bass, and/or the volume a half-notch, you can't tell the difference. As with all humbuckers, their tone, to my ears, is slightly compressed, but I find that a help when I have to carry the room and maintain an even volume, or even with a good sound man. Link to comparison:

[bloke]

Yeah, those are the ones that I'm considering. Maybe for Christmas present to myself, or maybe never...??

Thanks for the input!

The net output of my 72 4-string jazz pickups is less than with this five string... noticeably... but they are also less noisy.