hifi engine

Proton AMS 2583 Manual/help needed

I bought a used proton AMS 2583 and I was wondering if any of you might know know how to make it play sound through its coaxial/optical inputs. I cant find the user manual and everything I tried so far won't mak eit play DTS/AC3 or anything at all from these inputs...
Analog ins are fine though

Thanks in advance for your help