I owned the C47 for a while and was not happy with the built in dac. I bought a Musetec MH-da005 for about 3K. I know this may be above your budget, but some feel this compares well to dacs costing 10K. Much has been written here on the Audiogon digital forum about it. Some think it may be the end of the search. I wrote a detailed review.
https://forum.audiogon.com/discussions/musetec-lks-mh-da005-dac