The DAC provides analog support for the receiver, but there is also optical S/PDIF available from the same jack. Same goes for the transmitter as well but with an ADC which by the way has been tested now and verfied to provide CD-quality performance. But, if you plug in a digital interface on both ends (TX and RX), you should get a bit-for-bit copy on the receiver end.

We've made a few changes to the hardware to make it simpler to build and to use as well as designed an enclosure for it (learning CAD is so fun!)

Hope that answers your question.

Stu