Solved Audio channels reversed using USB

Not sure if this is a hardware or Win 8 problem. I've now run four dacs off two USB 2.0 ports and each has had the channels reversed, per the Windows 8 Sound test among others. There is no problem with the Dacs - I've checked elsewhere - and the interconnects from the Dacs have run to the proper speakers. One of the USB ports I've used belongs to the mobo and the other to a USB add-in card. So, where is the likely fault, on the mobo or within Windows? It's not the biggest deal - no problem switching channels - but I'd like to figure out what's behind it. Thanks,

Update: From some further exchanges, it seems some or all dac makers set up speaker interconnect ports looking from the back rather than the front. Screwy, since that means crossing wires if the unit is facing forward.