Do I even need to shield my Jazz bass?

[MEKer]

To me, I consider hum as much of a STOP sign as I do neck-dive. YMMV, I know. But I just won't have it or a bass I have to "fix" to get rid of it.

That said---good info here as usual! So good I'll say Thanks even though I don't have the problem.

 

[tlc1976]

Aluminum foil works fine as shielding. But remember the shield must be "grounded" (connected to jack body) to work. The only problem with aluminum foil is that you can't solder to it easily. The standard connect to aluminum foil is a wood screw into the body with lock washer that "bites" into the foil. Pickguards often use aluminum foil and the connection is made by having a foil tab come out of the cavity and goes around one of the pickguard screw holes. Then when you put the pickguard screw in it clamps the guard foil down against the tab to make connection.

But generally I use copper foil that is meant for stained glass window crafts. It is not expensive and has the advantage of already coming with sticky adhesive on the back. And of course you can easily solder wires to it to ground it.

I've never soldered to shielding. I always figured having the jack tightened in place against the foil was sufficient. With a washer for added surface area, and a star washer if needed for more bite. Since the outer case of the jack is ground.

 

[DiabolusInMusic]

When I asked a local guitar tech about shielding paint, he suggested I lay down a coat, let it dry for a day, then lay down another and yet another a day later. I also asked if I should paint it up and over the route's edge to ensure proper contact with the foiled pickguard, to which he said "Definitely!". Overall, the results were perfectly fine.

In this case, I used low-adhesive "artists white masking tape" to mask off the overlap's edges. What I didn't do was use any kind of plastic sheeting to protect the rest of the body, a mistake I don't plan on repeating. It seems the paint is incredibly runny and drippy. I only ended up with a couple of drip-spots and fortunately for me, they landed on the black portion of the burst finish.

I wouldn't recommend that paint that black paint. That is like the stuff Stew Mac sells. Use MG Chemicals Supershield. It takes only ten minutes to dry between coats, is more durable, and it will go to a lower resistance. As far as over spray/paint goes, you have to address it quickly otherwise it is in there forever. I just use a little graffiti spray (I think it is acetone) on a rag and wipe the conductive paint off with ease. If it is on nitro, fuhgeddaboudit. Also, you don't need to have overlap from the entire cavity, just a little lip. By the way, the job looks great

Let's hope your tech resolves the issue OP.

 

[Dan Morgan]

It helps sometimes to ground the electronics to the cavity shielding. If you're using that foil duct tape everyone has recommended it's really easy to do. Just shield the cavities, and then solder one end of a wire to the back of one of the pots or to a ground lug, and use the foil tape to tape the other end to the cavity shielding. Some basses now come with this already done via a wire screwed into the shielded wood (the ones with the black shielding paint).

I bought a 2008 Mexican fender jazz, supposedly noiseless pickups. I hadn’t noticed noise until I did more recording the last few years. It was bad enough I’ve blamed everything on setup except the bass and it’s noiseless pickups. I opened it up this week to find the ground wires screwed into a fixture on the wood just as you describe, except no paint or copper tape in there at all . Starting to wonder if I was swindled out of some shielding there? I’ve ordered some copper tape and am interested to see if it does the trick .

 

[tpaul]

I bought a 2008 Mexican fender jazz, supposedly noiseless pickups. I hadn’t noticed noise until I did more recording the last few years. It was bad enough I’ve blamed everything on setup except the bass and it’s noiseless pickups. I opened it up this week to find the ground wires screwed into a fixture on the wood just as you describe, except no paint or copper tape in there at all . Starting to wonder if I was swindled out of some shielding there? I’ve ordered some copper tape and am interested to see if it does the trick .

Yeah, they might have figured they could skip the shielding due to the noiseless pickups, but that's not true. You can get hum from unshielded wiring no matter what kind of pickups you have.

When you apply the copper tape, wrap a little over top of the control cavity so it contacts the metal plate.