Jazzmaster wiring with Shielded Pickguard

[BonesAreTheirMoney69]

I have a shielded pickguard like the one in the imaged attached. If it's shielded this way, and I use the Rothstein Wiring Diagram here, then which ground wires would be unnecessary? I want to avoid a ground loop.




Last time I posted, everyone helped me fix my wiring for my Jazzmaster, and it works great now with some electrical tape, but it was kind of trial and error.

The problem is I don't actually understand why it works, so I was just wondering if I could get some insight to learn about grounding. After that, I plan on rewiring it without electrical tape.

[timtam]

There's no such thing as a hum-producing ground loop in a passive guitar (even if a well-known pickup maker says there is ... but also refuses to provide the simple proof required). So physical loops are OK.

The components in the Rothstein diagram will be correctly grounded if they are in contact with the patches of foil on your pickguard as long as those patches are themselves grounded, or if those components have their own dedicated ground wires. The main foil patch is grounded because it includes the output jack, and the output jack rim is grounded by the guitar's cable - and that grounded rim is in contact with the patch. That patch then grounds the lead circuit pot bodies that contact it. As such the black wire from the output jack to the tone pot body is electrically redundant, but there's no harm in having it too (since ground loops aren't a thing). Some people regard a ground wire as more secure than relying on foil for component grounding (I'm ambivalent).

The rhythm circuit foil patch and toggle switch patch will need to be grounded in order to perform their grounding roles; or you can run a ground wire to the toggle switch body and rhythm circuit bracket.

Grounding the patches will also have some shielding effect, although the patches are rather small. You could cover the whole pickguard with foil (with conductive adhesive so it's electrically continuous). Then the output jack rim will ground all the foil at once, and also provide better shielding.

[BonesAreTheirMoney69]

There's no such thing as a hum-producing ground loop in a passive guitar (even if a well-known pickup maker says there is ... but also refuses to provide the simple proof required). So physical loops are OK.

The components in the Rothstein diagram will be correctly grounded if they are in contact with the patches of foil on your pickguard as long as those patches are themselves grounded, or if those components have their own dedicated ground wires. The main foil patch is grounded because it includes the output jack, and the output jack rim is grounded by the guitar's cable - and that grounded rim is in contact with the patch. That patch then grounds the lead circuit pot bodies that contact it. As such the black wire from the output jack to the tone pot body is electrically redundant, but there's no harm in having it too (since ground loops aren't a thing). Some people regard a ground wire as more secure than relying on foil for component grounding (I'm ambivalent).

The rhythm circuit foil patch and toggle switch patch will need to be grounded in order to perform their grounding roles; or you can run a ground wire to the toggle switch body and rhythm circuit bracket.

Grounding the patches will also have some shielding effect, although the patches are rather small. You could cover the whole pickguard with foil (with conductive adhesive so it's electrically continuous). Then the output jack rim will ground all the foil at once, and also provide better shielding.

Thanks for the insight on physical loops. I feel smarter after reading this post already.

I'm going to remove the black wire from the output jack to the tone pot, then shield the entire pickguard and see what happens. I was originally not getting any sound when following this diagram until I started using electrical tape over the shielding, so I'll have to recheck my wiring and rethink what went wrong.

Thanks again.