Manual

Chapter 4 - RB-ADDA Combined A/D and D/A Converter
Redbox User Handbook 4-1
4. RB-ADDA Combined A/D and D/A
Converter
4.1. Introduction
Fig 4-1: RB-ADDA Front Panel
Using 24 bit, 96kHz capable devices, the RB-ADDA A/D and D/A Converter is a 1U
rack-mount which produces an AES/EBU or S/PDIF level digital audio output from a
balanced XLR or unbalanced phono stereo audio input. The unit also produces a stereo
balanced XLR or unbalanced phono output from an incoming AES/EBU or S/PDIF
digital input signal.
The unit operates in four modes:
Master Mode - In this mode the unit receives an analogue audio
signal, which is digitised and formatted for digital serial
transmission (IEC958). The necessary clock signals are generated
internally from an on board master clock at a selectable rate
(32kHz, 44.1kHz, 48kHz, 88.2kHz or 96kHz).
Slave Mode - In this mode the unit automatically detects the presence of a digital
audio sync signal, if present at the digital input, and synchronises the digital output to
it. If no sync is present, no output will be generated.
Auto Mode - Here the unit synchronises to the digital audio sync signal if present at
the digital input and uses the internal master clock only if no sync input signal is
detected. In this case, the internal master clock is used at the selected sample rate.
Auto Lock Mode - This operates like the auto mode except that if no sync input
signal is detected, it will use the internal master clock to sync to the sample rate,
which was last clocked to.
When operating in sync modes, the front panel power LED flashes whenever the unit
is not synchronised to the incoming digital signal, or when the unit is being calibrated.
The RB-ADDA should be calibrated once it has been powered up for more than 10
minutes.
RB-ADDA
COMBINED A/D AND D/A CONVERTER