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Redbox User Handbook No 1
7
SYNCHRONISERS, DELAYS &
SILENCE DETECTORS
SY
NCHR
ONISERS, DEL
A
Y
S & SILENCE DE
TEC
TORS - RB
-DS2
7 RB-DS2 Audio Delay Synchroniser
Introduction
Fig 7-1: RB-DS2 Front Panel
The RB-DS2 is a stereo audio delay synchroniser used for resynchronising audio to video
following delay processes such as standards conversion, transmission delay, logo insertion,
video aspect ratio conversion and network delays. It can be used for fixed installations
to correct a permanent audio delay, or on an intermittent basis to provide occasional
correction, for example for live links. Accepting digital audio signals up to 96kHz, 24 bit, the
sonic quality of the RB-DS2 is superb and silent switching is used to provide the smoothest,
cleanest audio delay available.
The RB-DS2 has both balanced analogue and AES/EBU digital audio inputs and outputs on
3 pin XLR connectors. It can act as a combined A/D and D/A unit meaning that analogue
inputs can be delayed and output as AES/EBU and vice-versa. It is a stereo delay, but can
also be used as a dual mono delay to process each audio path separately, or as a mono delay
using the left inputs and outputs.
As standard the RB-DS2 can provide up to 10.5 seconds of delay at 96kHz sampling, 24
bit (42 secs at 48kHz, 16 bit). An internal Compact Flash™ expansion allows up to 16GB
of memory to be accessed providing delay times of over 24 hours, for example, to delay
a programme output across different time-zones, or to shift a broadcast programme by
1 hour for a satellite rebroadcast. Delay times can be selected in samples, fields, frames,
milliseconds, metres and, with the Compact Flash™ expansion, in hh:mm:ss. Frame and field
definitions can be for PAL (25 frame) or NTSC (30 frame) signals.
A front panel blue vacuum fluorescent display with rotary controller is used for selecting
the various settings of the delay, which include the source (analogue or digital), channels,
sample rate, sample bit width, format (PAL or NTSC), delay units and the delay itself.
Additionally, input peak digits can be selected from +12dBu, +18dBu and +24dBu for FSD
and two left and right pre-set potentiometers on the rear panel allow the input gain range
to be altered by ±3dB around the selected peak digits.
The analogue output gain range can be altered from -6dBu to +24dBu output level, ref FSD.
Both analogue and digital outputs can be separately muted and a front panel Bypass button
disengages electro-mechanical relays to divert both analogue and digital inputs to their
outputs. This is also disengaged automatically when a power-fail occurs.