A:B-W-Y-R, B:B-W-R
Plugged in USB JCAT FEMTO USB card 5V  Nothing
Plugged in regular USB  Nothing
" While the T+A DAC 8 DSD does not require the 5v as an operating voltage supply, it does require the 5v for identification. That information comes directly from T+A in Germany in response to my query. I believe that this is commonly referred to as "handshaking". Related?