You have a PC with a USB output and you have a fine DAC with a USB input. You can start with iTunes and just connect the PC to the DAC. I think the USB on your DAC will only accept 44 or 48 KHz audio, but it will give you a good idea of how it can sound. If you want to do higher resolutions you can get a usb to S/PDIF adaptor to connect the PC to the Byrston at higher sample rates.
Once you have this working you can try a different player like foobar (free) or J RIver ($50, but has a 30 day free trial).
I would suggest taking small steps before investing in more hardware.
Once you have this working you can try a different player like foobar (free) or J RIver ($50, but has a 30 day free trial).
I would suggest taking small steps before investing in more hardware.