I am using an old Sonos bridge to power 2 non-Sonos speakers in my outdoor kitchen. Having a hard time re-connecting to “line-in” feature for TV play. I assume direct Digital Optical cable wont work (don’t see input). I tried RCA’s directly with no luck. Thinking I need Optical converter/adapter into RCA’s. The speakers work with normal play (Spotify, etc) but can get the TV to connect.