The RB-OA3 has been designed for installation in a central technical area with cabling to custom panels, or selection switches, in each studio. If you don’t have any custom switch panels available, you can use an RB-OA3R in each studio. The RB-OA3R is a 1U rack mount switch unit for use in each studio that needs to be connected to the STUDIO 1-3 CONTROL connectors on an RB-OA3. It takes it’s power from the RB-OA3 unit so needs no power supply itself.