What is RixVox Audio Streamer Amadeus?

RixVox Audio Streamer Amadeus is an audiophile grade streaming computer-on-a-board
that serves bit perfect and ultra-precisely clocked data to any DAC, thus being the
foundation of the ultimate quality in digital audio reproduction and available to selected
manufacturers as an OEM part for their hi-end audio equipment.


How is RixVox Audio Streamer Amadeus different?


To begin with, RixVox Audio Streamer Amadeus is unique in its mission of being the
ultimate quality source in digital audio reproduction. This resulted in the most
unconventional engineering solutions. Through engineering diligence and a lot of
creativity RixVox team succeeded in diminishing the impact of the fundamental sources of
distortions and errors in the digital signal path to near-undetectable levels, to stream bit-
perfect digital audio.

  • A custom built, optimized for bitperfect audio Linux-based operating system RixVoxCore
  • Special designed 10-layers streaming platform RixVox Amadeus 1.6
  • Two internal hardware Master Clock
  • Isolated processor core for audio streaming
  • User friendly built-in web interface
  • Works with almost every commercially available model of DAC by inputs: USB, S/PDIF and I2S
  • Supported streaming inputs: Roon, MPD, Airplay
  • Support UpnP/DLNA standards
  • Bitperfect playback of audio formats: AAC, AIFF, ALAC, APE, DIFF, DSF, FLAC, MP3, OGG, WAV, WV and WMA
  • Supports DSD playback
  • Easily set up and playback from NAS, SATA and USB drives


What is bit-perfect (in simple terms)?

Distortions and errors caused by power source deficiencies, clock conflicts and
processor re-prioritisation are practically unavoidable. Even the best conventional
streamers can only strive to compensate for them, at times creating more distortion of the
signal. Therefore these digital losses, compensation artefacts and distortions are also
present in the analog signal prepared by the DAC. And they can and will be heard by an
audiophile. While this is accepted as the nature of digital audio reproduction and can be
mitigated to some extent, it is unavoidable.
However, it is also yesterday, thanks to Rix Vox.
RixVox Audio Streamer Amadeus is the first system that almost obliterates these forms of
digital distortions and errors, attaining the ultimate in bit-perfection.

No bit is lost and no bit is added during digital audio streaming. “What comes in – that comes out”.
In technical terms, RixVox Audio Streamer Amadeus serves I2S (PCM) and DSD streams
with up to 99,9997% accuracy*.
For a music lover, the digital audio fed into DAC’s from RixVox Audio Streamer Amadeus
will produce the perfect sound.
* – pending final measurements of particular board versions for each customer.


How RixVox Audio Streamer Amadeus achieves this?


In the development process RixVox team chose to approach the bit-perfection through
three highly innovative engineering solutions. Each of them separately addresses a
fundamental class of distortions and errors, and the sum of these solutions is the RixVox
Audio Streamer Amadeus.



Split Processor Core Functionality

The first and grandest innovation hides in the processor. RixVox Audio Streamer Amadeus
employs 1 GHz dual-core Cortex-A7 processor, that operates asynchronously. The tasks
that the processor executes are not shared between the cores, which is the conventional
approach, but veritably split between them, according to function. One of the cores
manages all of the board’s periphery and the other core takes care exclusively of digital
audio data.
RixVox team succeeded in reprogramming the processor on assembler level. Not a small
feat in itself, as the IT wisdom said – it could not be done, but most importantly splitting
the processor core functionality allows to avoid the whole class of errors that arise from
processor switching and sharing tasks between cores (re-prioritisation).


External Clocking


Another class of distortions and errors in the digital signal path arise from improper
clocking and bus clocking conflicts. These are the main sources of “jitter” in digital audio,
which means bits of data being served with the wrong timing. To counter it, RixVox Audio
Streamer Amadeus has a sub-board of a separate set of clocks, running at 44,1 and 96
KHz respectively. These ultra-precise clocks (optionally, with errors of less than 1 ppm)
govern everything concerning digital audio data. Thereafter bit-perfection of the streamed
data is guaranteed by ultra–precise external clocking. This is the second innovation*.
* – for even more demanding customers RixVox Audio Streamer Amadeus has the special
option of connecting a separate atomic clock with clocking errors far below the
measurable level.


Separate Power Supplies


Separate stabilised power supplies for each of the board’s main components is the third
innovation. It addresses the class of distortions and errors that arise from parts of the
board being momentarily under-powered. In digital as in analog circuits “under-powered”
typically means voltage drop. Where analog circuits tolerate voltage drops rather well,
digital circuits are highly intolerant to any voltage drop, they may generate switching and
calculation errors, hang-up, or initiate restarts. The common solution of just taking large
enough power supply does not address this properly, as it creates its own distortions.
RixVox Audio Streamer Amadeus therefore has four completely separate power
– for the processor,
– for the clocks,
– for the FPGA circuit,
– for the USB-OUT port.
This allows the system to function error-free with maximum precision and efficiency.
Complete software package
RixVox Audio Streamer Amadeus runs a closed custom Linux build. Our first and
probably the world’s first professional audiophile grade system for a streamer. The
software was developed in-house – optimised for asynchronous processor management
and external clocking.*
* – the system build is closed, as it contains optimisation measures that we consider
RixVox intellectual property. Therefore SDK for OEM manufacturers will not be available.
Porting of OEM manufacturer’s software will be provided by RixVox following separate


Connections to the future


RixVox Audio Streamer Amadeus provides system wide future-proofing through advanced
combination of hardware and software.
Hardware-wise there are: Ethernet 100 Bit/s port, one SATA controller, two USB2 ports,
one USB OTG port, display port, HDMI, native I2S and DSD (a separate 2-channel bus)
with hardware clocking, UART, SPI, I2C interfaces and more. IrDA, WiFi 2,4 GHz and
Bluetooth as yet more options. Please see data sheet for details.
On the software side: IRS, SPI and USR protocols, as well as digital DAC management
are supported as standard. HQ Player and Roon Player are supported natively. By order,
almost any customer software can be ported.


Extended upgrade-ability


By way of complex modular construction RixVox Audio Streamer Amadeus is positioned
to have its useful life extend well past that of its competitors and modern audio devices in
general. Every RixVox will be 100% upgrade-able via factory installed partial or complete
upgrade packages.


An elegant solution


On a personal note – though RixVox Audio Streamer Amadeus is technically a computer,
that will spend its life hidden away in a block of metal, we love it. The complexity of the
project boggles the mind and the final product is a thing of beauty – conceptually,
technically and visually.


Hardware Specification

Streaming Platform  RixVox Amadeus with Cortex-A7 Dual core 1GHz
Video  Dual core Mali 400 GPU, FullHD (1080p) video playback
USB  USB2 host x 2 and USB2 OTG x 1
Ethernet  10/100/1000Mbps
WiFi (option)  Yes
Bluetooth (option)  Yes
Video out  HDMI and LCD port
Interfaces  USART, SPI, I2C, IR Port, 80 GPIO’s
Input Power Main power supply 5V 1A (typically ~0,2A) x 1
Extended power supply 5V 0.2A x 3
USB power supply 5V 1A x 1
Dimensions (W x D x H) mm 134 x 51 x 23 mm



Audio Specification

Digtial Audio Inputs  I2S, S/PDIF, USB, SATA, NAS, Network streaming
Digtial Audio Outputs  I2S, S/PDIF, USB
Sample Rates  I2S and S/PDIF

– 44.1 kHz to 352.8 kHz 16bit/24bit

– 48 kHz to 384 kHz 16bit/24bit


– 44.1 kHz to 352.8 kHz 16bit/24bit

– 48 kHz to 384 kHz 16bit/24bit

Master Clock  Work in Master and Slave modes