XDR, though I don't have personal experience with these particular products, Wadia makes some of the best products in the world in the digital audio domain.
I have once heard one of their DACs feeding a Bryston amplifier that was driving two B&W speakers. I have also watched a HT system that had a number of Wadia DACs in the chain.
Wadia products are expensive, but deliver world class performance.
Cheers
