I am trying to hook up my sound card from our computer to a Denon PRA-1100, which is connected to a Rotel amp. I get no sound. But I do get sound when I connect the computer right to the amp. Is this a volume out issue on the sound card, a digital v analog signal issue or could the be something wrong with the pre-amp. I will be connecting my CD player up to it later on this evening to check that it works - but any thoughts at this point would be helpful. Thanks