Redbox User Handbook No 1
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10
10 RB-DSD1 Digital Silence Detection Unit
Introduction
Fig 10-1: RB-DSD1 Front Panel
The RB-DSD1 digital silence detection unit works in a similar way to the Sonifex RB-SD1
analogue silence detection unit, but has AES/EBU, S/PDIF and TOSlink inputs and outputs
instead of analogue inputs and output respectively. Designed to switch from one input to
another in the event of loss of audio, the unit is ideal at transmitter sites, or after the master
output of a studio, to switch in another audio source, or simultaneous broadcast, should a
master source fail.
The unit can switch:
•
On loss of level of the main input.
•
On loss of level on one channel of the main input.
•
On loss of synchronisation lock of the main input.
The RB-DSD1 has 2 x digital stereo audio inputs, each one selectable via front panel MAIN
and AUX push buttons, from either AES/EBU balanced XLRs, S/PDIF unbalanced phonos
or TOSlink unbalanced optical inputs. Sample rate converters on each input mean that
sources of different sample rates can be used with the output sample rate being defined
independently. Each input is user-defined as either the main source or auxiliary source and
both sources are monitored for failure, each having a remote failure alarm. The colour of
the MAIN and AUX push-buttons indicate which input is the current output channel (green)
and which input is the waiting channel (red) input, with a flashing LED indicating loss of
synchronisation.
In the event of the main source dropping below a pre-set level for a pre-determined
amount of time, the unit will automatically switch through to the auxiliary signal. The
silence detect level is adjustable between -39dBfs and -84dBfs in 3dBfs steps via front panel
DIPSwitches. The silence interval can be adjusted between 0 seconds and 252 seconds in 2
second steps via another front panel DIPSwitch block. A small cover panel can be screwed
in place to obscure the DIPSwitches to prevent tampering of the settings.
There are 2 stereo outputs to allow for distribution of the selected input to multiple outputs.
Each output is available as simultaneous AES/EBU balanced XLRs, S/PDIF unbalanced
phonos or TOSlink unbalanced optical outputs. The output sample rates are selectable via
rear panel DIPSwitches from one of 32kHz, 44.1kHz, 48kHz, 88.2kHz, 96kHz, 176.4kHz or
192kHz.
The unit has TTL wordclock BNC and AES/EBU XLR synchronising inputs as standard and
optionally, the RB-SYA and RB-SYD synchronisation boards can be fitted to synchronise
SYNCHRONISERS, DELAYS &
SILENCE DETECTORS
SY
NCHR
ONISERS, DEL
A
Y
S & SILENCE DE
TEC
TORS - RB
-DSD1
