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Redbox User Handbook No 1
DIGITAL AUDIO CONVERTERS
DIGIT
AL A
UDIO C
ONVERTERS - RB
-ADD
A2
2
9
1
Sync Button
and LEDs
Frequency Set
Button and LEDs
Bits Button
and LEDs
A/D Source Select
Button and LEDs
CS Data Button
and LEDs
D/A Source Select
Button and LEDs
Reset
Button
2 RB-ADDA2 Combined A/D and D/A Converter 24bit 192kHz
Introduction
Fig 2-1: RB-ADDA2 Front Panel
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 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.
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 nominal
gain incorporated to give a total signal 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.
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