So there is a large, in wall speaker system installed where I am living. It appears to be three floors of Channel Vision systems. However, the only way I can find to input into the system is through a Cat5e jack, and I have no idea how to hook up any type of receiver to a Cat5e input. I can't find anyway to plug any rca thing through a converter into this jack. What do i need to be able to play at least an ipod through a cat5e system like this?