Introducing The New Alpha USB Reference Series

The Alpha USB Reference Series Has ultra low Phase noise reclocking technology from the Alpha DAC Reference Series 3P Plus increased enclosure mass and vibration isolation. The result is an unprecedented Level of time domain Coherence That Results In dramatically Real Music reproduction.

read Robert Harley’s comprehensive review of the Alpha USB Reference Series and the new Alpha DAC Reference Series 3P in the July/August 2025 issue of The Absolute Sound

Alpha USB Reference Series Front Panel

 

Alpha USB Reference Series rear Panel

 
 

Product Highlights

Introducing the Alpha USB Reference Series

The Alpha USB Reference Series is a noise isolating, reclocking digital audio interface with an asynchronous USB 2.0 High Speed Audio input optimized to connect to modern high speed, low latency USB 2.0 High Speed Audio drivers. It has selectable coaxial SPDIF or balanced AES/EBU digital audio outputs.

The USB input is galvanically (DC), capacitively and inductively isolated from the digital audio output which is re-clocked using the proprietary ultra-low phase noise clock technology in the Alpha DAC Reference Series 3P. The result is an unprecedented reduction of time and frequency domain noise and dramatically improved audio realism.

The Alpha USB Reference Series also builds on the strengths of the Alpha USB Series 2 with proprietary USB 2.0 High Speed Audio input software optimized for modern high speed, low latency USB 2.0 High Speed Audio drivers. The result is very significantly improved audio quality.

The Alpha USB Reference Series has a USB 2.0 High Speed Audio input data connection and switch selectable output signal type – either coaxial SPDIF using a 75Ω BNC connector or balanced AES/EBU using an XLR connector. Sampling rates up to 192kHz and word lengths up to 24-bit are supported. 

Great care was taken in the design of the Alpha USB Reference Series to isolate streamer/server noise on the USB input from the AES/SPDIF digital audio output. The USB input receiver and processor are powered by the USB input source, while the AES/SPDIF digital audio output ultra-low phase noise master clocks and line drivers are powered by a separate isolated linear power supply. There is also no DC connection and a very high degree of capacitive and inductive isolation between the USB input and the AES/SPDIF digital audio output.

Three key factors combine to achieve the unmatched audio performance of the Alpha USB Reference Series; ultra-low phase noise audio output master clocks using the same technology in the Alpha DAC Reference Series 3P, high speed, low latency input software and an unprecedented degree of electrical isolation between the USB input and the AES/SPDIF digital audio output 

The Alpha USB Reference Series is designed to work with modern Linux based music servers and Apple Macintosh and Windows PC computers.

A User Guide and 6’ power cord are included with the Alpha USB Reference Series. 

 
 

Controls & Indicators

  • Output Select: switch selects SPDIF or AES/EBU type outputs

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

Specifications

  • Input: USB Audio 2.0 Standard asynchronous connection, type B receptacle

  • Outputs: switch selectable, coaxial SPDIF on 75Ω BNC connector or balanced AES/EBU 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 5.38”D, 2.88”H including feet

  • Weight: 2.8 lbs.

  • Mains power: 100/120/240VAC, 50/60Hz, IEC power input connector

  • Power consumption: 3W, designed for continuous operation