Technical notes, Loss of sync – Studio Technologies 76DA V.4.12 User Manual
Page 46
Issue 9, May 2014
Model 76DA/77 User Guide
Page 46
Studio Technologies, Inc.
for Surround
where non-technical personnel are allowed
only to use the rotary level control. A con-
figuration parameter, previously described
in the Model 71 Control Console Configu-
ration section, allows button operation to
be disabled.
Rotary Level Control
The rotary level control is used to manually
adjust the post-fader surround and stereo
monitor output levels. Its operating charac-
teristics are identical to those of the Model
77 Control Console, discussed earlier in
this section.
Dim
The dim function allows the post-fader sur-
round and stereo monitor output levels to
be reduced by a fixed amount. Its operat-
ing characteristics are identical to those of
the Model 77 Control Console, discussed
earlier in this section.
An indication is provided should the dim
button be pressed when button operation
has been disabled. Its associated LED will
flash briefly but no operating change will
occur. The LED will continue to display the
status of the dim function as selected by
other Model 77 and Model 71 units.
Reference Level
The reference level button sets the post-
fader surround and stereo monitor output
levels to their preset values. The operat-
ing characteristics are identical to those of
the Model 77 Control Console, discussed
earlier in this section.
An indication is provided should the ref-
erence button be pressed when button
operation has been disabled. The associ-
ated LED will flash briefly but no operating
change will occur. The LED will continue
to display the status of the reference level
function as selected by other Model 77 and
Model 71 units.
Technical Notes
Loss of Sync
The Model 76DA relies on an external
timing reference (sync) source for proper
operation. This can be in the form of an
AES3, word clock, DARS (AES11), bi-level
video, or tri-level video reference signal. In
most cases the sync signal will be con-
nected to the sync input BNC connector
located on the Model 76DA’s back panel.
Alternately, a configuration choice allows
the L/R input of the AES3 source currently
selected for monitoring to also serve as
the system’s timing reference. Whenever
a valid sync signal has been connected
to the Model 76DA the sync status LED,
located on the unit’s front panel, will light.
The sample rate of the monitor output
channels will reflect the rate of the sync
input and, if a video sync source is utilized,
the configured rate.
If a valid sync signal is not present sev-
eral visual indications are provided. On
the Model 76DA the sync status LED will
flash. On all connected Model 77 Con-
trol Consoles the 4-digit LED display will
cease normal operation, instead alternat-
ing between the words no and sync. When
a valid sync signal is again connected
the Model 76DA’s sync status LED will
light steadily. On the Model 77 units the
word sync will momentarily be displayed
followed by a brief display of the monitor
output sample rate. The sample rate will
display as 32.0, 44.1, 48.0, 88.2, 96.0,
176.4, or 192.0, reflecting the impact of the
sync source rate and the Model 76DA’s
configuration.