I'm just starting to learn about high resolution audio. From what I understand, DVD-A and multichannel SACD will output high resolution signals only via HDMI. Neither my pre/pro nor my DAC has HDMI. The audio de-embedder strips the high resolution audio signal from the HDMI and converts it to either coax or optical, so that it can be accepted by other devices. I don't care to use the analog outs because I'm pretty sure my DAC is superior to the one built in to the OPPO.