“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
The Alpha USB is an asynchronous High Speed USB Audio 2.0 to digital audio interface designed to provide the highest possible audio quality from computer and music server audio sources.
The Alpha USB has a USB Audio 2.0 Standard input and switch selected digital 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. There is no DC connection and also a high degree of capacitive and inductive isolation between the USB input and the digital audio output.
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 digital 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 Apple Macintosh and Windows PC computers and Linux based music servers. For Linux, the operating system must be ALSA 1.0.23 or above. It must also have the ability to select the output device. Apple computers using Snow Leopard or later operating systems also interface directly with the Alpha USB. It is not necessary to install a USB Audio 2.0 Standard driver for those operating systems.
PC’s using Microsoft Windows 10 release 1703 and above do not require installation of the Alpha USB Windows driver and the driver provided with Windows should be used. Only Microsoft Windows PC’s using Windows XP, Vista, 7, 8, 8.1 and earlier versions of 10 require the Alpha USB Windows driver which is available on the Downloads page.
A User Guide 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: USB Audio 2.0 Standard asynchronous connection, type B receptacle
Outputs: switch selectable, coaxial SPDIF on 75Ω BNC connector or balanced AES on 110Ω XLR connector
Supported sampling rates: 44.1kHz to 192kHz
Supported word lengths: up to 24-bit
Supported operating systems: Apple, Windows and Linux
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