Rega DAC-R User Manual
DAC-
Digital to Analogue Converter
R
Contents
Introduction 1
Technology 2
Front panel indicators & operation 3
Back panel - inputs and outputs 4
In use - Digital output & optical inputs 5
Filter settings 6
Connectivity (examples) 7
USB set-up and connectivity 8
Remote control and notes on high resolution playback 9
Technical specifications 10
Glossary of terms 11
Owners log 12
Introduction
The Rega DAC-R is a 16/20/24-bit at 32kHz to 192kHz digital to analogue
converter. Incorporating an enhanced version of the Rega designed circuit,
the DAC-R offers the highest possible resolution over all inputs including
fully asynchronous USB with the addition of remote functionality.
Developed to be simple to set up and use, the Rega DAC-R is designed
to optimise performance from any two channel PCM digital audio source.
With the PC now widely accepted as a credible medium for storing and
streaming music,the use of high quality lossless files such as WAV, FLAC
and ALAC offer performance through the DAC-R equal to and in some
cases better than Red Book CD. Great care has been taken to remove
noise generated by the PC and other input sources. (During development
this was identified as a major drawback with many DAC’s on the market
today).
The DAC-R is housed in a custom aluminium and steel case and boasts
a pair of Wolfson DAC IC’s, three user selectable digital filters and one
isolated asynchronous USB, two isolated Co-axial inputs & two Toslink
SPDIF inputs.
The DAC-R has been designed and engineered to integrate perfectly into
any system and achieve the highest performance in its class. We hope
you enjoy this Rega product for many years to come.
1
Technology
The optical and coaxial input stage comprises a Wolfson digital receiver
with a high stability, low jitter clock driving the receiver PLL. The receiver and PLL have their own dedicated power supplies. The DAC stage
comprises a pair of parallel-connected Wolfson WM8742 DAC’s, that are
driven via a buffer stage, which ensures the integrity of the data being fed
to the DAC IC’s similar to the arrangement used in the Isis reference CDP.
The USB input stage is comprised of a bit perfect XMOS USB Audio 2.0
with asynchronous clocking. The USB input stage feeds the Optical and
Coaxial input stage via an isolating transformer giving total isolation from
the host computer.
The output amplifier employs a discrete differential, multiple feedback
filter and output amplifier, with a high cut-off frequency for use with higher
sample rates. We decided not to use a sample rate converter and process
the data at the incoming sample rate which keeps the signal processing to
a minimum. Jitter was minimised by synchronously clocking the digital data
with our receiver PLL (removing any jitter from the input signal).
All the capacitors associated with the analogue signal path are audio grade
bypassed with MMK polyester capacitors, and low impedance conductive polymer capacitors are used for DAC decoupling. The power supply
utilizes a toroidal transformer, fast rectifier diodes and again audio grade
capacitors. There is a power supply for the control micro controller, separate from the digital & analogue audio stages. Special attention being paid
to the inter IC control signals ensures the control data noise is kept to a
minimum.
2
Loading...