The Sonifex RB-ADDA bi-directional audio converter was originally released in 2001 and has had sales of over 1,000 units. On IBC stand 8.561, this product’s “big brother” has been announced with release expected in November 2005. The RB-ADDA2 is a high performance, enhanced version of the RB-ADDA providing the following additional features:
- It supports higher sample frequency rates up to and including 176.4kHz and 192kHz.
- It has additional independent AES/EBU and Word Clock synchronising inputs, so that the A/D and D/A sections can operate independently, with the digital outputs synchronised to an external master reference clock.
- It has TOSlink optical digital audio input and output.
- It has front panel push-button switches for all the main settings. The buttons are arranged in sets, where pressing the button advances the current selection and LED indicator.
- A serial RS232 port is included so that the RB-ADDA2 settings can be controlled remotely. The front panel LED indicators alter automatically when using RS232 commands.
Eamonn Heffernan, Sales Manager at Sonifex Ltd said “With the current trend for recording at higher sample rates, the RB-ADDA2 provides some future-proofing for customers who want a cost effective way to upgrade their recording facilities to 24bit, 192kHz. The RB-ADDA2 is more suitable for studio use because all of the operational controls are on the front panel, instead of on the rear (like the RB-ADDA). The synchronising inputs also mean that the A/D and D/A sections can be used separately and the TOSlink provides greater connectivity.”
The RB-ADDA2 A/D and D/A converter is a 1U rack-mount which produces an AES/EBU, S/PDIF or TOSlink optical level digital audio output from a balanced XLR or unbalanced phono stereo audio input. It also produces a stereo balanced XLR or unbalanced phono output from an incoming AES/EBU, S/PDIF or TOSlink optical digital input signal.
The A/D SOURCE push-button is used to select from either the balanced or unbalanced stereo analogue inputs and this push-button also defines the input level for full scale digits at one of +12dBFS, +18dBFS or +24dBFS. These values can then be fine-tuned by using rear-panel pre-set potentiometers which give another ±3dB of gain adjustment, allowing a signal range from +9dBu to +27dBu. The RCA phono inputs have a further 10dB gain incorporated to give a total gain range of -1dBu to +17dBu for full-scale digits.
For the digital output, there are three push-button switches to select the sample frequency, bit depth and status bit modes. The FREQUENCY button allows selection of the master sample frequency from one of 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz. The BITS button sets the output bit depth as one of 16, 20 or 24 bits, and the CS DATA button defines the content of the channel status bits embedded within the digital audio stream.
The SYNC button is used to select the synchronisation input, from Word Clock, AES/EBU or the D/A input, and also the synchronisation mode of the digital output. The A/D section of the RB-ADDA2 operates in four selectable synchronisation modes and the SYNC button flashes whenever the unit is not synchronised to the incoming digital signal.
The D/A section has one SOURCE push-button which is used to select the digital input source from AES/EBU, S/PDIF or TOSlink optical and which also sets the analogue output level to be generated for full scale digits, from either +12dBFS, +18 dBFS or +24 dBFS. There are factory-set internal level controls for fine tuning the analogue output gain adjustment. If no digital audio source is present, the D/A SOURCE button flashes.
