04-Dec-2014, 18:54
I played around with a short DIY usb cable connecting to a Macbook Pro. Signals (Pins 2&3) are sufficient once a connection is established and connecting ground (Pin4 at the A end) is necessary to establish that connection (even worked when I used the ground post of the D250 instead of the USB input). There was no advantage sonically not to have a ground in the USB cable.