The Apogee Groove is the best DAC USB and portable headphone amplifier to listen to music on your Mac or PC. Groove takes the same high quality audio technology found in the world's most prestigious recording studios and brings it to your laptop computer. Connect Groove to the USB computer port and speakers or speakers amplified to the Groove audio output. It's so easy. The Groove output offers wide power to any impedance, and the Apogee Constant Current Drive technology makes the headphones sound the best. You will be amazed by the difference in sound quality - the precise stereo image, incisive bass and extraordinarily clear loudspeakers.