This DAC is back up for sale. This unit, having M2Tech USB, will not work yet with the latest El Capitain for MAC. If you are using this and are not willing to go back to Maverick for a little while, this is not for you.
The issue is a joint problem with MAC as well as M2Tech, so until both are straightened out, you are in the wind using El Capitain with this Chord DAC.