i have an IMAC, yamaha reciever and a focusrite pro 40. Goal here is to get sound from imac, to focusrite then to reviever that has a 5.1 system hooked up to it. firwire from imac to focusrite right now.... then fiber optic audio cord from focusrite to yamaha reciever. i have no idea why its not working. I chose the setting on mac so it goes thru the focusrite. i can see the sound bars moving when i open the focusrite software. but there is something wrong from the foucusrite optical out to the yamaha reciever optical in. any ideas thanks..