I also tried the Digital In port on the WT1 and it has the same low volume issue. Has anybody tried the Digital In port on this? My guess is the Analog stuff works well  but the Digital doesn't seem to work all that well. Maybe I have a deffective unit. I tried to contact the US supplier(Micca)...

I received my W1 today from Micca and tried it on both USB(connected to PC as USB audio card) and RCA input connected to Karaoke machine. The unit is pretty impressive. The latency is up to spec. But I hit one issue trying to hook it up still on RCA input but the source is from the headphone...