AQ’s Diamond USB cables pull out all the stops and therefore feature 100% perfect-surface silver conductors (that is, solid silver—not just silver-plated—conductors), which AQ suggests minimise “distortion caused by the grain boundaries that exist within any metal conductor, nearly eliminating harshness and greatly increasing clarity compared to OFHC, OCC, 8N, and other coppers.” Then, AQ gave its Diamond-series USB cables sophisticated foamed-polyethylene insulators chosen “because air absorbs next to no energy and Polyethylene is low-loss and has a benign distortion profile.”
To further minimise the potential sonic effects of the cable dielectrics, AudioQuest fitted the Diamond USB cables with the same, patented 72V dielectric-bias system that is found on the firm’s upper tier analogue cables. The DBS system applies a bias voltage across the cable’s insulators with an eye toward minimising “both energy storage in the insulation and the multiple non-linear time delays that (can) occur.” The result, says AQ, is that “sound appears from a surprisingly black background with unexpected detail and dynamic contrast.”
Next, in the interest of “preventing captured RF interference from modulating the equipment’s ground reference” the Diamond USB cables use a carbon-based 3-layer noise-dissipation system. Finally, cable terminations feature ‘direct-silver’ plated pins and are attached using AQ’s proprietary solder (a type of solder said, oddly enough, to sound better and to provide more durable and reliable connections than conventional ‘silver solder’).
As you can tell from some of the passages I’ve quoted above, AQ’s product messaging is some of the best going, but do the Diamond-series USB cables, which are obviously chock-full of technical features, actually sound as good in reality as they do on paper? In a word, yes!