Alpha USB

“The Berkeley Audio Design Alpha USB is a breakthrough product that not only overcomes the limitations of the USB interface, but provides a state-of-the-art method of getting audio out of a computer.”
—Robert Harley, The Absolute Sound, Issue 214
“After four months using the Alpha USB, in combination with the Alpha DAC Series 2, I'm continually astonished by its level of performance. In fact, the Alpha USB is so good I've yet to hear a better digital interface. Period.”
—Chris Connaker, The Computer  Audiophile,  March 2012


Product Highlights

The Alpha USB is an asynchronous High Speed USB to digital audio interface that extracts the highest possible audio quality from computer audio sources. 

The Alpha USB features a High Speed USB 2.0 input data connection and switch selected audio output signal type – either coaxial SPDIF using a BNC connector or balanced AES using an XLR connector. Sampling rates up to 192 kHz and word lengths up to 24 bit are supported.  

Great care was taken in the design of the Alpha USB to isolate the noisy computer/USB environment from the digital audio output. The USB receiver and processing are powered by the computer, while the output master clocks and line drivers are powered by a separate isolated linear power supply.

Two key factors combine to achieve the excellent audio performance of the Alpha USB - the unprecedented degree of electrical isolation between the USB input connection and the audio output and the very low noise/low jitter performance of the individually tested audio output master clocks.  

The Alpha USB is designed to work with both Apple Macintosh and Windows PC computers. Apple Macintosh computers using Snow Leopard or later operating systems have a High Speed USB Audio Driver that interfaces directly with the Alpha USB. It is not necessary to install a special driver. Microsoft Windows PC’s require the included Alpha USB Windows driver which works with Windows XP, Vista and 7. 

A User’s Guide, Windows driver CD and 6’ power cord are included with the Alpha USB. 



Controls & Indicators

  • Output Select: switch selects SPDIF or AES type outputs

  • Status LED: Green indicates USB Lock, Amber indicates Standby


  • Input: High Speed USB 2.0 asynchronous connection - type B receptacle
  • Outputs: switch selectable, coaxial SPDIF - BNC, 75Ω or balanced AES type - XLR, 110Ω 
  • Supported sampling rates: 44.1kHz to 192kHz
  • Supported word lengths: up to 24-bit
  • Supported operating systems: Apple Macintosh and Microsoft Windows 
  • Enclosure dimensions: 2.3”H X 10.5”W x 5”D, 2.55”H including feet
  • Mains power: 100/120/240VAC, 50/60Hz, IEC power input connector
  • Power consumption: 3W, designed for continuous operation