I see that Shenzhen audio is having 15% off sales going on until tomorrow. I plan to use pair the DAC with my node2i via coaxial. DAC directly hook to my Parasound A21 (via xlr). Speakers will be Paradigm Persona B. I also plan to add a sub to the setup via RCA. Room is small. Listening distance will be about 7 ft away. Why adding external DAC? I think using better DAC might improve the high notes. Which would you suggest? Thanks!