I have an old JVC TH-A55 5.1 Channel. It has a Digital In Optical.
Link to its image
https://drive.google.com/file/d/1NbxxMcUU2TCkspkFwUG47aMhTGYoECBO/view?usp=sharing
I have a newly built desktop pc with an Asus A320M-K motherboard with SPDIF OUT-digital audio connector.
Link to its image...