Digital optical to coaxial audio converter, digital audio components cannot be connected (digitally) to one another because different manufacturers use different input/output formats (TosLink/Optical or Coax). Audio Authority's Model 977 series solves the problem by allows to convert digital signals from coax to optical or vice versa. The 977R (receiver) converts the optical output of a digital source (DVD or Satellite Receiver) to Coax for connection to Dolby Digital or DTS receivers. No matter what type of digital audio, Audio Authority can make it work.