Lea Paul type guitar shielding (P90)

[pk317]

Hi guys,
I want to learn how to make a proper shielding and I'm going to experiment with this on my LP style P90 guitar. I red a lot of info about it, including on this forum, but still have some points that are not really clear for me. Ok, so here we go:

LP style guitar, with 4 cavities (knobs, switch and 2 pickups). All covered in copper foil. 

1. All the pots are sitting on the foil, so they're all connected (continuity test confirms that). Does it mean that I don't need to run a ground wire between the pots as usually shown in wiring diagrams?
2. Input jack socket also sits on the foil, do I still need to wire the ground wire to the sleeve?
3. Hot output from pickups go to the switch, ground wires from pickups go to the ground lug of the switch, that touches the foil, that is connected to the foil of knobs cavity that is connected to the jack socket. Again, do I need to run another wire other then hot output from switch to the input socket?

Basically, all my questions are related to the fact that now all the knobs, switch, pickup covers and input jack socket are connected through the foil, so I'm not sure whether I need to run a separate ground wires or not. Sorry if this is a dumb question, I just want to understand the basics.

Thanks.

[Deleted]

Slug tape. Is copper tape
Sadly if look for a item for a set market IE guitar shielding they can up the price but when you use the same thing as Slug tape and it's cheaper

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1. All the pots are sitting on the foil, so they're all connected (continuity test confirms that). Does it mean that I don't need to run a ground wire between the
pots as usually shown in wiring diagrams?

They are connected but not a great connection so I would connect the pots hard wire wise.


2. Input jack socket also sits on the foil, do I still need to wire the ground wire to the sleeve?

Yes always good to have a direct path


3. Hot output from pickups go to the switch, ground wires from pickups go to the ground lug of the switch, that touches the foil, that is connected to the foil of knobs cavity that is connected to the jack socket. Again, do I need to run another wire other then hot output from switch to the input socket?

Don't trust a bit of foil as connection, if it breaks , has any bends that can increase the current flow and up to he resistance.
Yes the foil is a Faraday cage but one made of paper thin. Would you want to wear a suit of that and walk in to 1000v

[pk317]

Mar 18, 2022 6:55:05 GMT -5 @angellahash said:

1. All the pots are sitting on the foil, so they're all connected (continuity test confirms that). Does it mean that I don't need to run a ground wire between the
pots as usually shown in wiring diagrams?

They are connected but not a great connection so I would connect the pots hard wire wise.


2. Input jack socket also sits on the foil, do I still need to wire the ground wire to the sleeve?

Yes always good to have a direct path


3. Hot output from pickups go to the switch, ground wires from pickups go to the ground lug of the switch, that touches the foil, that is connected to the foil of knobs cavity that is connected to the jack socket. Again, do I need to run another wire other then hot output from switch to the input socket?

Don't trust a bit of foil as connection, if it breaks , has any bends that can increase the current flow and up to he resistance.
Yes the foil is a Faraday cage but one made of paper thin. Would you want to wear a suit of that and walk in to 1000v

angellahash, thanks for the reply.

Won't kind of double ground path (via foil and via wires) create a ground loop? Or is it something that won't really affect the sound/shielding?

[Deleted]

It's not a good grounding
It's like using a KitKat foil to ground the house electrics

[unreg]

Mar 18, 2022 8:27:19 GMT -5 pk317 said:

Won't kind of double ground path (via foil and via wires) create a ground loop? Or is it something that won't really affect the sound/shielding?

hi pk317.

I asked a similar question, and was instructed that ground loops don’t exist inside guitars… so don’t worry about a potential ground loop affecting sound/shielding. Follow @angellahash’es advice, wire from a ground-point to shield is a super direct/strong ground path; relying on foil for that connection is a mistake bc foil is thin and can break easily, causing terribleness to envelope your guitar sound; which will cause you to open your guitar electronic cavity(s) again.

[newey]

We have always advised that best practice is to not run guitar signal through the shielding, for the reasons stated above.

It is not that ground loops do not exist inside a guitar, they do. But the loops are so small as to be of no concern, they aren't long enough or extensive enough to generate noise.

[pk317]

Ok, thank you all for your answers, will experiment with that.