improving SQ using optical connection?

[andrew_brown]

It would be ideal for me if Spark would read directly from my NAS.  In the meantime I use an optical (toslink) cable from a Sonos Connect to my Dialog.  Sound Quality is outstanding (but limited to CD quality).  Technically it should be better than using Bluetooth as there is no compression involved.

I would not worry about the quality of the optical cable: if it works, it will work perfectly.