I am building a simple outboard input selector to accompany my S.E.X. amp. I've had it for almost two years, and I'm finally tired of only having one input. This seems like a simple build, but I'm faced with a early dilemma. I will be using a small aluminum project chassis for the selector, and I have a plethora of un-insulated RCA panel jacks. Now since the selector won't have ground running through the chassis, I was wondering if I'll need to buy some nice RCA jacks with nylon washers to isolate the signal from anything. Seems simple enough, I just don't want to make a move until I'm sure. Thanks.