A quick follow up. The market is full of poor fitting OPTIC cables. The cable should "click" when inserted into a optic socket, mine did not but still worked.
I bought an optic to RCA analog converter for around $25 from amazon. There are lots of venders and the products look the same so take your choice.
The converter is a couple of inches square and is well built. I plugged in the optic cable and no "click" so I wiggled it a bit and everthing worked, for a while.
Then distortion, then silence.
I took the box apart, easy to do and removed the circuit board. The optic socket was a little loose and had three solder joints. I must have broke a solder joint when I wiggled the cable.
I got out my fine tip low heat soldering iron and touched up the three joints then put a bead of silicon around and under the socket to lock it down.
If anyone buys one of these converters the first thing I would do is take it apart and silicon the socket. This will save solder job in the future. Mine works OK now.