DAC-R Digital to Analogue Converter
Contents Introduction 1 Technology 2 Front panel indicators & operation 3 4 In use - Digital output & optical inputs 5 Filter settings 6 Connectivity (examples) 7 Back panel - inputs and outputs USB set-up and connectivity 8 Remote control and notes on high resolution playback 9 Technical specifications 10 Glossary of terms Owners log 11 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.
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.
Front panel indicators & operation IR sensor Sample Rate LED On/Off Filter Input Input locked LED Power on/off When the power button is pressed the Rega logo illuminates. Input Selects the 5 available digital inputs. Push to advance. Filter Selects the three avaiaible filters. Push to advance Input locked indicator Indicates the digital input signal is valid and the PLL in the receiver is locked. When the Input locked LED is off, the soft mute is activated.
Back panel - inputs and Outputs Inputs USB - Isolated Asyncronous/type B connector Optical Digital Input 1- Optical/Toslink Optical Digital Input 2- Optical /Toslink Co-Ax Digital Input 3- Isolated 75Ω Co-axial Phono Co-Ax Digital Input 4- Isolated 75Ω Co-axial Phono Outputs Digital output (via receiver & PLL) -SPDIF Optical Toslink Co-axial/Phono Isolated 75Ω Analogue Output Left and Right Phono Power Mains/line input IEC C13 type Fuse Fuse holder 4
In use Power-up the DAC-R using the power switch on the front panel. After a few seconds you will hear an audible click from the output mute relay and the analogue audio will be active. Please note: the front panel will display the previously selected setting’s displayed before the unit was last powered down. If the currently selected input has an active source connected, the ‘Input locked’ LED, along with the appropriate incoming sample rate LED, will illuminate.
Filter settings The cut-off points of the filters are in the upper end of the frequency range. However, due to complex technical phenomena, this will have an effect lower in the frequency band. For further description, see the glossary of terms. These settings are a matter of personal taste and may only offer subtle changes. We suggest using Filter setting 1 and trying different settings with various music and equipment. Filter setting switch & LED’s - Push to advance to the next filter.
Connectivity (examples) 1 USB A-B/ 2 OPTICAL/3 CO-AXIAL This page offers ‘suggested connectivity’. With so many products offering a number of options, it is important to check the manual of the product your are connecting for the appropriate or optimum output connection and settings required to operate properly. Please note : This unit only accepts two-channel PCM digital audio.You cannot connect a Dolby Digital 5.1/7.1 or a DTS signal as they will not be recognised.
USB Setup and connectivity Connect a USB A-B type lead (as illustrated) from the DAC USB to a USB output on your PC. IMPORTANT: Before you can use the USB function of the DAC-R you must first download the Rega USB Windows driver and install it on your PC. This driver is available for download from the Rega website, www.rega.co.uk. Go to ‘product range’ and select CD players / DAC’, then DAC-R. Under product downloads on the product page you will see the USB driver. Follow the instruction for installation.
Remote functionality The DAC-R is supplied with a mini system remote which gives the user the ability to switch inputs via a single button marked ‘DAC Input’. The Solaris system remote (sold separately) also allows remote function of the three digital filters. Notes on high resolution playback The DAC-R can operate up to 192kHz when used with a capable soundcard connected via the Co-axial, optical or USB input.
Technical Specifications DAC 2x Wolfson WM8742 Frequency Response (100KΩ load) Filter 1 selected Low data rate 44.1/48KHz = 10Hz -0.05dB to (44.1K) 20.02KHz (48K) 21.7KHz -0.03dB Medium data rate 88.2/96KHz = 10Hz -0.05dB to (88.1K) 28.7KHz (96K) 31.2KHz -3dB High data rate 176.4/192KHz = 10Hz -0.05dB to (176.4K) 44.1KHz (192K) 47.7KHz -3dB Maximum output level = 2.175V into 100KΩ load Bit resolution (all inputs) 16 to 24bit Supported data rates = 32, 44.1, 48, 88.2, 96, 176.
Glossary of terms ASYNCHRONOUS An asynchronous USB DAC uses its own clock to regulate the data rate from the computer, which allows for jitter-free data transfer PLL Phase lock loop PCM Pulse code modulation SPDIF Sony Philips digital interface protocol SOFT MUTE Software mute (not output mute) SOFT KNEE FILTER Filter with a large transition band which reduces dispersion and delay HALF BAND Filter where the transition region is centred at one quarter of the sampling rate APODISING FILTER Filter exhibiting a
Owners Log (1) Owner.................................................................................................. Date..................................................................................................... Where purchased................................................................................. (2) Owner.................................................................................................. Date.............................................................................
Rega Research Ltd. exceptional hi-fi designed and made in England.
