Toslink / Apple TV connection / Unitilite

Whilst we wait for some sort of Spotify support I decided to just unplug my Apple TV and use its airplay capabilities ( also setting up a NAS , just wanted to mess about with  airplay )  Plugged in the cable to the ATV little red light and other end into digital 4 of the UL …. NO SIGNAL ARGHHHHHH …. is there a setting on the apple tv i don't know about ? I looked through the settings but didn't look like i needed to switch to optical out .. looks like a constant feed ?? Only one thing .. the cable makes a nice click into the ATV and doesn't into the Naim ,don't want to force it anymore but it seems to go in ok and looking at the forum some people say the connection isn't great / tight .. maybe another cable maybe I'm doing something wrong …