Upgrading a Sony dav hdx500
My parents have a Sony dav hdx500. They want to hook their cable box and fire TV stick to the surround sound. But this box doesn't have any inputs. I was going to see about swapping the main unit with just a new receiver but read that sometimes the speakers aren't compatible. Can anyone tell me if the speakers would be compatible with a normal receiver or are they stuck upgrading everything?
As an alternate I'm going to see if their cable box and tv at least has an optical connection as that may be my only option. Those are becoming a bit rare. So not sure if they have an optical option.