Okay, well then I have a couple of questions in regards to shielding without soldering (as I have no experience with soldering yet, and was going to buy an iron soon and wait until I had enough experience to shield the bass properly):
1) I know a pickup can pick-up electrical hum. Can a wire alone pick up electrical hum as well or is it done solely through the pickups? Reason I ask is that I've seen lots of people actually shield the wire canals in between cavities as well, but this requires soldering. I would like to simply shield the cavities and run another wire through the canals creating conductivity through the cavities, but this would leave the pickup wires in the canals exposed.
2) Where exactly do I connect the final ground to? I was thinking of soldering it to the ground prong on the output jack, but obviously can't do this without soldering. Could it be connected to the bridge grounding wire?
NOTE: On my Squier fretless jazz, some hum goes away when I touch the strings/bridge, because I'm now grounding the circuit with my body, this makes me believe that the main ground on the bass isn't properly grounded in the first place. I feel like if the bass was properly grounded then it wouldn't need to pass through my body to get to ground. Also, my P Bass or Warwick do not lose hum when I touch the strings.
Here are some wiring diagrams for the two basses I'd like to shield. If anyone can point out where to connect the ground, that would be great.
Typical jazz schematic:
Thanks.
Shielding without soldering and use of aluminum foil. Note that a shield is a CONDUCTIVE box enclosing the electronics as best you can. All parts of this "box" must be connected to ground which means if you use several pieces of foil EACH PIECE must be connected to the next piece and the whole thing connected to ground. Best is as much as possible to use a single piece of foil folded to fit it all. With aluminum tape, the glue is not conductive (unless special tape is ordered) and thus EACH piece of tape must be connected to ground. Standard method is to run a wire from ground to a wood screw through the tape with a lock washer under the head to "bite" into the aluminum. The lockwashers with lots of tiny teeth are best. A wire runs from the screw to ground.
The problem here is you really don't get out of soldering because the ground wires from the tape pieces MUST be connected to ground and that almost always means soldering.
1. Yes wires pickup hum too but if you leave channels unshielded (but run a ground wire between pickup cavity shielding and ground) and twist pickup wires, hum pickup will be minimal. remember pickup cavity foil MUST be connected to ground or other cavity foil (which is grounded).
2. The correct place to connect all these grounds to is the barrel (outside) of the output jack. As you note there is a solder tab to do this. And typically there are wires from there going to be soldered to the backs of the control pots. This is all one solid connection and you can consider ground to be any place along there.
Note that in many basses a single grounding point is used which can be the jack body OR sometimes a screw is put into the wood with a solder lug where all grounds arrive. That common point then runs a wire to the jack.
Note that if you use a common ground screw you can avoid soldering by using crimp-on lugs on the ground wires that you put over the screw before you screw it into the shielding and wood. But you still have the problem of connecting to the jack ground.
Sometimes you can get around this. For example, in a jazz bass the jack can go through the metal control plate. Any conductive metal that the jack is mounted on (or presses against when mounting like say shielding foil will connect to that jack. So shielding a jazz bass with aluminum and no solder is rather easy because you coat the cavity with foil running it up over the lip where the control plate covers it. Now since the jack is mounted on the metal plate that now is ground and since that plate screws down and presses into to foil coming up over the lip at the screws, contact is made and no solder is needed. You just have to be sure that all pieces of aluminum are somehow connected together! This would apply to your Squire Jazz (which typically are not shielded well if at all)
In the diagram the primary ground is at the jack. Note that funny triangular symbol of several lines, THAT is ground. Note that this ground is shown around the bass, ALL those places should already be wired together. And that ground should also connect to your shield foil. Note solderless method above using foil clamped under control plate at screws. If the control plate contacts foil you do not have to worry about running extra ground wires to the jack or other grounds (back of pots). But you DO need to make sure (meter) that all foil pieces are connected to all other foil pieces!
A very quick and dirty Jazz bass Aluminum shield job can be had by getting some decent aluminum foil and a can of spray on glue ("art" glue like Scotch "spra-mount" or Borden equivalent). Coat one side of foil with spray glue to hold it in place so it doesn't vibrate. Form foil into cavity rubbing it down so glue sticks. run foil up over lip of cavity and trim to fit under control plate. Put control cover and controls back on with screws mashing foil to bass. Done. Don't even both with pickups yet. Try bass and check out any improvements. (should be dramatic with both pickups on full) If there is still hum that goes away or changes when you touch the strings with both pickups on full then you may need to shield pickup cavities next, grounding that foil to cavity foil with screws, lockwashers and wires. At that point there should be almost no hum that changes when you touch strings or ground (control plate, jack body, strings etc.)
Good luck!
