While, for casual listeners, the Mac's DAC (digital-to-analogue converter) delivers decent enough quality via the headphone output, it's a low cost solution, and one that's easily improved upon in terms of noise, jitter and overall fidelity. Arcam's rPac is a small, solidly built aluminium box designed to do just one thing: deliver pristine stereo audio output from your USB-connected Mac.



Link: Techradar