The DAC2x being a 15k$ DAC, I would consider auditioning an MS600 or 818v2 audio endpoint with it.

This would be much improved from the C15 digital output.

Also, configure your MD600 to run the core as well to take the C15 completely out of the equation once you have an audio endpoint like the MS200/MS600/818v2.

DSP8000SE, DSP7200SEHC, DSP5200SE sides, DSP7200SE rears, 861v8, 210, Sim2 Ultranero 4, Stewart Cinecurve 2.35:1, XEIT CM-5E Anamorphic lens, Dune HD Duo Cinema 8K and Wireworld Platinum 48G HDMI -> UHD722 -> Shunyata Omega Ethernet. Shunyata/Furutech power-cables/filters. SR Master Fuse@861v8. Uptone Etherregen with 10MHz OCXO clock.