By the way how are you connecting from the computer to the dac? Remember some low end soundcards will use the RCA as a digital out or even the headphone out too as an optical. If so you will need to go into the soundcards software to set it up digital output.
Remember only disable the soundmax if it is not your digital sound output card! I assume you are using a different card for this?
Remember only disable the soundmax if it is not your digital sound output card! I assume you are using a different card for this?

