RFI/noise will find a way to ride into the cage from any wire entering the cage. My music server has a built in Faraday cage to isolate certain stages from noise entering or exiting the cage. The means of isolation are quite extraordinary. For the signal to pass through the cage, it is first converted to optical so that optical fiber passes the barrier and then it is converted back to an electrical signal.
Build a Faraday cage around your equipment.
I just realized that there is an abundance of Material (cloth) that has EMF blocking characteristics on the market now. Considering it is a woven material flexible and can be easily sewn by ordinary means, this could easily be used to create a simple form of a faraday cage around your high end stereo equipment. They even have Curtains for your windows. I intend to experiment with it and have already started looking at potential heat problems and effectiveness of ONLY a partial cage, because of course you want to leave much of the Front and back of your equipment open. I believe it has a lot of potential in stopping interference between individual pieces of your equipment package and especially for those who like me have their setup contained in a rack/structure of some kind. There are numerous places that can be approached like even laying a sheet of the material over cable runs to keep out stray signals. This can be done in simple ways or you could get very deeply involved in configuring everything in the system to incorporate the blocking material. Some simple places it could be utilized are simply a sheet of it placed on a shelf before placing the equipment on it or as a simple barrier between pieces of equipment. Attention to the types of material should be considered a high level of concern as the different types have different characteristics. Has anyone else experimented with this?