You must use the correct OS driver. You must also install it correctly. First run the dmg file, which will unzip and execute creating a container. Then execute the container. It will ask for your computer password. When its done, then plug the USB cable. Then select the device in system preferences - audio/sound. Then if you are playing from iTunes, make sure that the sample-rate matches the rate in utilities - audio MIDI.
Steve N.
Empirical Audio
Steve N.
Empirical Audio