Sonifex Redbox RB Series, Руководство пользователя, Страница: 25 / 160

Redbox User Handbook No 1
9
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 channel status can be forced to either Professional Mode (PRO), Consumer
Mode (CON) or to follow the mode of the input (FOLLOW).
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 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, 96kHz,
176.4kHz or 192kHz).
Slave Mode
In this mode the unit is synchronised to an external source, using the digital audio sync or
D/A input signal from which the clock signals are stripped, or to the TTL level Word Clock.
The FREQUENCY LED will indicate the synchronised sample frequency and if no sync is
present, no output will be generated.
Auto Mode
Here, the unit is synchronised to an external source, using the digital audio sync or D/A
input signal from which the clock signals are stripped, or to the TTL level Word Clock. If no
sync signal is present the unit runs from the onboard master clock at a rate selected by the
front panel control (32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or 192kHz).
Auto Lock Mode
This operates like the auto mode except that if no sync signal is present the unit will run at
the closest master clock rate to the last locked incoming signal. The FREQUENCY LED will
indicate the synchronised sample frequency.
When operating in sync modes, 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 12dBFS, +18dBFS or +24dBFS. The
RCA phono outputs have a further 10dB nominal attenuation to reduce the signal to that
expected by consumer equipment. 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.
The RB-ADDA2 automatically decodes 50/15µs emphasis if this is indicated by certain
channel status bits in the incoming digital audio data. In both A/D and D/A sections, audio is
sent to all of the outputs simultaneously. A red LED indicates when power to the RB-ADDA2
is on.
2
DIGITAL AUDIO CONVERTERS
DIGIT
AL A
UDIO C
ONVERTERS - RB
-ADD
A2