The defacto standard for all external DACs is going to be USB. Specifically, the asynchronous USB developed by Wavelength. In theory, this method of transfer introduces no more jitter than a single one box CD player design because the transport (computer) is slaved to the DACs word clock.
Wavelength, dCS, and Ayre are the only ones using it as far as I know.
Wavelength, dCS, and Ayre are the only ones using it as far as I know.