I have an Ack! dAck have found that it is best to have a transport with low jitter. I have a cheapie Toshiba 5 disc changer and unless I pass the data stream through a Monrchy DIP to correct jitter, I end up with harsh highs, which I believe is due to high jitter. Also, if you are getting a dAck, then you will need a transport with coax digital out - the dAck does not have a TOSLink interface.