I've recently rezerected a Technics SA-DX950 DTS Amp and am having trouble getting 5.1 through the Xbox One. I'm using a fairly basic set of Samsung satalite speakers which work ok, my main issue is with the sub (Eltax 03949). When I run a test all the speakers work accept the Sub. The connection between the Xbox and the Amp is optical and the connection between the Amp and the Sub is coax although I suspect it may need to be just a basic phono but its been so long this I used his stuff I can't remember. Any suggestions on the Amp set up and connection would be appreciated.