One thing you've gotta love about Audioengine is that they don't rest on their laurels. Even though the Audioengine D1 is our best-selling DAC, they decided to crank things up with the D3. It looks like a flash drive or the old iPod shuffle, but crammed in there is an upgraded asynchronous DAC and nifty headphone preamp, ready to be plugged into any USB port. This is portable headphone goodness at its very best: Audioengine made sure that the D3 can handle low-impedance phones, and they even included a 1/4"-to-mini adapter in the box with the D3. This is a killer piece of gear, and a great intro to improved computer audio.