Can I introduce a DAC to this??

If it has a digital out (either coax or optical) then you can add a DAC. There are some really good affordable DACs available today. A used MSB Link DAC II or III, Perpetual Tech. P3A, Channel Islands, Birdland Odeon Lite, Scott Nixon, dACK!, etc., would likely be far superior to your changers internal DAC.

Enjoy,

TIC