Alpha DAC Reference Series 2

The unprecedented resolution of the Alpha DAC Reference Series allowed Berkeley Audio Design to develop analog circuits and digital algorithms that achieve completely new levels of realism in the Alpha DAC Reference Series 2. The only way to understand the level of excellence of the Alpha DAC Reference Series 2 is to hear it.

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The Alpha DAC Reference Series 2 delivers significantly better sound quality than its predecessor
and in ways that matter the most to musical enjoyment. After listening to music through the Alpha
DAC Reference Series nearly daily for the past two years, I'm shocked that the Series 2 could push
the state-of-the-art that much further."                                                                                                                                        (Full review coming in the October 2016 issue of The Absolute Sound)
Robert Harley                                                                                                                                                                             The Absolute Sound                                                                                                                                                                  July 2016


Listening through the Berkeley Audio Design Alpha DAC Reference Series 2 has enabled me to hear my                        favorite music again for the first time. I now hear fine details that I've never heard in all my years of                               listening. Who'd have thought there was so much more to be squeezed from our favorite recordings?                                 (Full review coming)

Chris Connaker
Computer Audiophile                                                                                                                                                              June 2016


Product Highlights

The original Alpha DAC Reference Series was a breakthrough product that reduced noise, particularly in the time domain, to levels significantly lower than any audio D to A converter previously available. The result was an immediacy and presence of music reproduction that was closer to the microphone feed than ever before. Very fine spatial and timbral information heard in real life that was previously lost or hidden by noise was revealed by the Alpha DAC Reference Series.

The unprecedented resolution of the Alpha DAC Reference Series allowed and demanded further development and perfection of digital algorithms and analog circuitry that otherwise would not have been possible. The lengthy development process that resulted in the Alpha DAC Reference Series 2 was challenging and resulted in design improvements that we feel again define the edge of what is possible. The only way to appreciate the level of performance achieved by the Alpha DAC Reference Series 2 is to listen to it.

The presence and sonic reality of the Reference Series 2 is also made possible by tremendous electrical and mechanical noise isolation coupled with extreme time domain stability. Ceramic aerospace circuit board materials are used in all critical areas and the enclosure is carefully engineered to minimize electrical noise and maximize mechanical and thermal stability. The Reference Series 2 weighs 30 pounds and the entire enclosure is precision machined from solid billet 6061-T6 aluminum alloy.

A high output metal IR remote control with direct input source selection is provided with the Reference Series 2.

Careful consideration was given to providing the highest possible fidelity reproduction of DSD files by the Alpha DAC Reference Series 2. 99+% of modern DAC’s, including the Alpha DAC Reference Series 2, use multi-bit D/A converters because they provide better performance than 1-bit converters - even DAC’s who advertise “native” DSD compatibility. So, at some point, the 1-bit DSD stream must be converted to multi-bit for all of those DAC’s.  

We could, like many other manufacturers, convert 1-bit DSD to multi-bit within the Alpha DAC Reference Series 2 and show “DSD” in the front panel display. That would be the easiest approach from a marketing standpoint and would also be very simple and low in cost to implement. But that approach would also mean increasing the amount of processing in the DAC during playback which would degrade audio quality, and audio quality is the reason the Alpha DAC Reference Series 2 exists.

Virtually all reproduction of DSD files using external DAC’s is with a computer based music server as the source. If 1-bit DSD to multi-bit conversion is done first in the computer it can be performed with extremely high precision and superior filtering that preserves all of the content of the DSD file. Computer DSD to multi-bit conversion can be at least as good as that performed in a DAC and without adding processing noise near or in the D/A converter chip. Also, conversion of DSD to 176.4 kHz, 24 bit AIFF or WAV files can be done ahead of time resulting in no conversion processing occurring during playback. Another advantage of computer based DSD to PCM conversion is that if higher performance DSD versions such as DSD 4X appear in the future, they can be easily supported with a software upgrade.

For all of these reasons, DSD capability for the Alpha DAC Reference Series 2 is provided by a state of the art software application, JRiver Media Center, that provides either real time conversion of DSD 1X and DSD 2X to 176.4 kHz, 24 bit PCM during playback or, for the best possible audio fidelity, easy conversion to 176.4 kHz, 24 bit AIFF or WAV files prior to playback. The JRiver Media Center software application is included in the price of the Alpha DAC Reference Series 2 and either Windows OS or Mac OS versions are available.  




  • Input sampling rate: 32kHz to 192kHz

  • Input word length: 24-bit

  • Ultra low phase noise Precision Clocking at 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz and 192kHz sampling rates ± 100 ppm

  • Two channel analog stereo outputs: XLR balanced with pin 2 positive and RCA unbalanced

  • Digital Inputs: AES - XLR, 110Ω; SPDIF1 - BNC, 75Ω; SPDIF2 - BNC, 75Ω; TOSLINK - Toslink optical connector

  • HDCD decoding detects 16-bit flag at 44.1kHz or 24-bit flag at all sampling rates

  • Multiple digital filter options

  • Balanced analog output level: +18dBu (6.15Vrms) maximum, +12dBu (3.1Vrms) or lower recommended

  • Unbalanced analog output level: 3.25Vrms maximum, 2Vrms or lower recommended

  • Digital volume & balance control: 0.1dB/step with .05dB/step L/R gain trim, 60dB range  

  • Frequency response at ≥ 88.2kHz sampling rates: ± 0.1dB from < 0.1Hz to 35 kHz,  - 3dB at 59kHz for 176.4kHz and 192kHz sampling rates

  • Distortion at recommended levels: all products ≤ -120dBFS

  • THD+N at maximum level: < -110dBFS

  • Firmware upgradeable through signal inputs

  • Enclosure dimensions: 3.5”H X 17.5”W x 12.5”D

  • Weight: 30 lbs.

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

  • Power consumption: 25W