Alpha USB

About the Alpha USB

The Berkeley Audio Design Alpha USB is an asynchronous USB-to-digital-audio interface, not a digital-to-analog converter. It accepts computer or music-server audio over USB and outputs either 75-ohm coaxial S/PDIF through a BNC connector or 110-ohm balanced AES/EBU through an XLR connector. A rear-panel switch selects the active output, with only one output active at a time to minimize jitter. Its design separates the USB input circuitry from the output circuitry using galvanic, capacitive, and inductive isolation, while precision reclocking and separate clock and output-driver power supplies are intended to reduce computer-generated noise and timing error. The original Alpha USB is an older product generation; Berkeley Audio Design currently lists newer Alpha USB Reference Series and Alpha USB Series 2 products, so the original model should be regarded as no longer manufactured, although documentation and support information remain available.