How to connect TV audio sound out digital optical only to analog RCA
Digital Optical Coax to Analog RCA Audio Converter Adapter
Fiber-optic cable - Wikipedia
Buy Easyday Digital Optical Optic to Analog (L/R) Stereo Audio Converter Adapter - Changes Digital Coaxial or Optical SPDIF into Stereo 3.5mm Jack or L/R (Red/White) RCA Audio Outputs - Includes AC