@Eppie : Sorry, I saw your suggestions (with which some I discuss below only after I had posted the following. In particular I have noted my concern with the DAC converters, that I have no RCA or coaxial HDMI connection and that using the Media Player path has not worked so far):
Denon themselves seem to have pointed the way to the DAC converters. So far their other suggestion of using the assignable Media In with the RCA cables and then naming the Media Input 'CD' (as suggested already on the forum) hasn't worked.
I have considered changing to a Yamaha AV Receiver RX-V4A which has the coax input but is a bit more expensive rather than buying a converter. This is because the reviews about such converters that I have read on Amazon show roughly 9-15% of problems or failures such as poor sound, poor volume, distortion or unwanted sounds.
In my search for an answer I would very much appreciate if there are any recommendations or advice from members about DACs
With thanks for any response,
Tony