I'm using a 25 year old Yamaha CDX660 CD player as a transport, connected via a premium coax cable to a Cambridge Audio CXN. I'm wondering if sound quality would be improved by swapping the Yamaha for the Cambridge Audio CXC transport? Basically I don't know how much of the 'work' is done by the transport and how much by the DAC. Although the Yamaha is old (very!) it works perfectly, so maybe its age doesn't matter? Any thoughts/ advice would be greatly appreciated. Thank you.