Stupid?

Have Bel Canto CD2 and interested in buying a DAC3 to go with it. I know I would run my balanced cables from the DAC into my amp. How is the CD2 connected into the DAC? Via AES? I also need to connect my sub which at this time is connected to my CD2 via Rca's as I am using the balanced into my amp.
Thanks for the help as I called Bel Canto 4 days ago with no response.