flykantech.com DCA-II The Digital to Analog Audio Converter box takes your coaxial/optical(S/PDIF or Toslink) digital audio source and converts it to standard analog left/right audio, available for connection to an external device such as an amplifier or recording deck via standard RCA-style jacks. You can bridge your legacy sound system with digital sources such as DVD and CD players that don't have RCA-style analog outputs.