Studio Technologies 76DBA V.3.00 - Manual (Page 21)

Model 76DBA/77B User Guide Issue 1, November 2010
Studio Technologies, Inc. Page 21
for Surround
remain enabled. However there might be
special cases where this resource isn’t
desired and it can be disabled.
Auxiliary Stereo Monitor
Output Nominal Level
The nominal level of the auxiliary stereo
digital and analog monitor outputs can be
configured to match the requirements of
a specific installation. Devices connected
to the auxiliary stereo digital and analog
monitor outputs could include an amplifier
associated with a loudspeaker system or
inputs on self-contained amplified loud-
speakers. (These types of devices must
include a means of adjusting their output
level.) This configuration setting defines
the relative output level when an input
source is connected and the auxiliary
stereo digital and analog monitor outputs
are enabled. The choices are 0, –6, –12,
or –18 dB. The 0 dB setting will typically
be correct when connecting to the input of
a device that’s not associated with a loud-
speaker system. With no gain or loss, this
setting creates a unity-gain input-to-output
relationship. Devices such as amplified
speakers will often perform better when re-
ceiving signals with a lower nominal level.
In this case the ability to comfortably use
a level potentiometer may be enhanced by
selecting the –6, –12, or –18 dB settings.
Sync Source
The Model 76DBA requires that the desig-
nated external timing reference (sync) be
defined. Three of the choices—word clock,
DARS, and video—are associated with a
signal that is connected to the sync input
BNC connector. The fourth choice allows
the L/R input of the currently selected sur-
round or stereo digital audio input to serve
as the system’s sync source.
Sync Input Termination
The sync input circuitry can be configured
to terminate the signal connected to the
back-panel sync input BNC connector.
When termination is selected a 75 ohm
load is applied to the signal. When the
sync input is not terminated the input im-
pedance is very high, essentially applying
no load to the source. If the sync source is
connected only to the Model 76DBA then
enabling termination is typically appropri-
ate. However, if the sync source is being
“shared” by multiple inputs then care must
be taken so that the signal is only termi-
nated by one device.
Audio-Synced-to-Video
Sample Rate
If a video sync signal is being used as the
Model 76DBA’s timing reference the sam-
ple rate of the connected digital audio sig-
nals must be specified. In most cases the
default value of 48 kHz will be appropriate,
but rates from 32 to 192 kHz are available.
Pre-Fader Surround/Stereo
Input C Direct Digital Monitor
Output Type
To meet the needs of specific installations
the nominal impedance and level char-
acteristic of the pre-fader surround and
stereo input C direct digital monitor outputs
can be selected. They are selected as a
group; configuration of individual digital
outputs is not provided. If the digital output
signals are going to be connected to bal-
anced AES3 inputs then the setting that
provides a source impedance of 110 ohms
and a nominal 5 Vpp output level would
be appropriate. If the digital output signals
are going to be connected to unbalanced