Shielding inside of amp

[Steveo]

I got some shielding for my amp. I got shielding tape and these thicker rectangular pieces. I was going to stick the thicker pieces on the bottom of my headshell but not sure about tape. Has anyone ever stuck the tape to the inside of the chassis? Any benefits or pretty much the same as what an aluminum chassis would already do by itself? Thanks

[xtian]

You can't improve on the RF rejection of the chassis itself, assuming the chassis is properly earthed. But most chassis have an open side, and by adding a "lid" to the chassis, making it completely enclosed, you can sometimes improve RF rejection. Just note that all sheilding you add needs to be electrically connected to earth.

Are you having noise now that you're trying to fix? Maybe you just need a shielded (co-ax) run from the input jack to the first stage, for example. Let us know which amp, etc.

[ViperDoc]

That's interesting. Say if you're using foil on the inside floor of the head cab under the chassis, what's the best way to ground that? Just over extend it to contact the mounting flange, or would you wire the shield panel to a washer, or something? Thanks.

[Phil_S]

To close the open side of the chassis in a head case, I smear ordinary glue on the bottom (where the open side will be) and then apply heavy duty aluminum foil, the kind you find in the kitchen. It's cheap. It works as well as anything. I use a bunched up rag to rub it onto the glue. No one sees this, so it can have some wrinkles in it. Your chassis is going to make contact with it, so I don't see a need for anything fancy to insure it's grounded. You'll need to run screws through the bottom of the case into the chassis. Theyr're going to contact the foil, too. Don't overthink this. Save your tape for something that really needs tape.

[Blindog]

To close the open side of the chassis in a head case, I smear ordinary glue on the bottom (where the open side will be) and then apply heavy duty aluminum foil, the kind you find in the kitchen. It's cheap. It works as well as anything. I use a bunched up rag to rub it onto the glue. No one sees this, so it can have some wrinkles in it. Your chassis is going to make contact with it, so I don't see a need for anything fancy to insure it's grounded. You'll need to run screws through the bottom of the case into the chassis. Theyr're going to contact the foil, too. Don't overthink this. Save your tape for something that really needs tape.

Yep, simple yet effective. Used this method on my last 5E3 build.

[xtian]

You just have to make sure the contact between chassis and foil is good. I've chased some vibration noise (specifically Fender HRD, where the back panel is covered in foil) because the contact was intermittent.

[ViperDoc]

Sounds easy enough.

[R.G.]

A can of spray on pressure sensitive adhesive is a great tool for making aluminum foil into 12" wide aluminum shielding tape. Or you could spray on an adhesive layer inside the amp, with masking to control the overspray, and just lay the foil in place and tear/cut off the excess.

[Steveo]

Ok thanks all. I got these mu metal .004” thick sheets called ultraperm 80. Ill stick them to the bottom of the head shell. The chassis has threaded inserts. These should make contact with the sheets. Ill save the tape for my guitars. Theres not a lot of noise just wanting to make it as quiet as possible.