I am running an upgraded XU208 USB module in my DAC. A couple folks measured it and found that it worked really well in this specific application (Holo Spring) better for example than when adding a Singxer SU1 I2S converter box. Analogue was supposed to be the tweaky format but digital has it beat at this point.
HAL wrote:
I prefer I2S Bus over all of them, but not a widely adopted standard for external DAC connection. Used in about 99.9% of DAC's internally for separate Data and Clock lines.
USB2 Audio is my second choice for a fully asyncronous bus flexible buffer length interface. The USB interface at the DAC does all the high precision clocking in the DAC.
It is just getting the PC power supply noise off the interface. Very simple actually, just break open a USB2 cable and break the +5VDC connection and add your own regulated low noise supply. Lots of those out there. LT1083 +5VDC regulators work very well. Hard to beat the iFi iPower low noise 5VDC regualtor for $50.
If you have to reclock the USB interface, the XMOS U8 or XU208 USB2 Audio interface in the DAC sucks.
YMMV