I want to connect this DAC with my PC. I have 2 options. One is using USB, the other is using S/PDIF ( on My motherboard - M4A78T-E ). I am not sure how good the PDIF port is, because it is on a motherboard instead of a professional sound card. I know USB supports 16bit 48K sample rate, while PDIF can support 24bit/192K. If I mainly use 320K mp3 or APE as the source, what is the best option for me? I can not compare now since I do not have a PDIF cable. I may get 1 to compare if more people think PDIF will output better quality sound.