Connecting Windows PC to DAC

You can use a usb to digital interface. Most have RCA outputs but you could use a RCA to XRL adapter. Some have XRL outputs, but they are more expensive. You also need to decide if you want 24/192 or not. Not sure if you DAC has that or not.

Here are a couple of converters to look at, although there are lots out there.

M2Tech HiFace

and

M2Tech Evo

These are generally referred-to as USB converters. There is a large range in SQ from these. You get what you pay for, and this is the most important part of the digital audio system. The lower the jitter of the master clock and the design and power system, the closer it will be to analog sound quality. The Off-Ramp 5 has S/PDIF, AES/EBU, I2S, HDMI I2S outputs.

Steve N.
Empirical Audio

FWIW, a friend is using the Musical Fidelity USB-to-RCA converter (not a DAC), with satisfying results. I have heard the system and it sounded fantastic to me. This is one of the cheaper options out there, too.