Since your Krell has digital inputs, as others have indicated you can still use it as a DAC. It will probably sound like it always did with a decent transport, say Cambridge Audio or Project, for under a grand. If you go the Bluesound Vault route
you do get a ripper transport DAC and storage all in one. My Bluesound units have mostly mechanically failed after around 4 years of use so personally I would stick to buying the transport and then you don’t have to burn the CDs to listen to them