Replacing RCA Input Jack

I want to change out the RCA female input jack on a Mark III amp. Does the jack required to be insulated from the chassis? A vendor has a note that the jack they sell is not insulated and is only suited for mounting on plastic or other non-conductive surfaces. But does this warning apply to the Dynaco amps?

Thanks

These amps isolate the ground for the audio inputs, so yes, it needs to be insulated. Probably easiest to just replace it with a similar jack already mounted on a non-conductive board.

Bob or Roy can probably set you up with what you need ...

Thanks sKiZo for confirming.