Studio Technologies 780-03 V.4.15 - Manual (Page 43)

Model 780-03/790 User Guide Issue 1, April 2015
Studio Technologies, Inc. Page 43
for Surround
the Model 780-03 the sync status LED, lo-
cated on the unit’s front panel, will light. The
sample rate of the pre- and post-fader digital
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 several
visual indications are provided. On the Mod-
el 780-03 the sync status LED will flash. On
all connected Model 790 Control Consoles
the 4-digit LED display will cease normal
operation, instead alternating between the
words no and sync. When a valid sync sig-
nal is again connected the Model 780-03’s
sync status LED will light steadily. On the
Model 790 units the word sync will momen-
tarily be displayed followed by a brief dis-
play of the active sample rate. The sample
rate will display as 44.1, 48.0, 88.2, or 96.0,
reflecting the impact of the sync source rate
and the Model 780-03’s configuration.
If during normal operation the sync source
changes from one valid rate to another a
visual indication is provided. On the Model
790 units the new sample rate—
44.1, 48.0,
88.2, or 96.0—will momentarily be displayed.
Any time that a valid sync signal is not con-
nected to the Model 780-03 the pre- and
post-fader digital monitor outputs will auto-
matically revert to an internally generated
sample rate of 48 kHz with no digital audio
content present. This audio “black” signal will
allow most connected equipment to con-
tinue to function correctly with, of course, no
meaningful audio signal present. As soon as
a valid sync signal is again connected to the
Model 780-03 the pre- and post-fader digital
monitor outputs will automatically switch to
their correct sample rate and audio signals
will again be present.
Power Down
Great care was taken in the Model 780-03’s
design to minimize the chance that clicks,
pops, or other objectionable audio signals
will be present on the post-fader digital
and analog monitor outputs. A power-down
circuit supplies the main microcontroller
integrated circuit with an indication that a
power loss is imminent. When this condi-
tion is detected the digital monitor outputs
will switch to silence (digital audio “black”)
in preparation for a complete loss of signal.
Electromechanical relays associated with
the analog monitor outputs will change to
their mute state to minimize the chance of
signal transients reaching the connected
loudspeaker inputs.
Power-Up Messages
Upon AC mains power being applied to
the Model 780-03 all connected Model 790
units will go through a power-up sequence.
The sequence starts by each of the indi-
vidual LEDs lighting in a “walk-through”
sequence. Then the 4-digit display tests
all its LED segments. Finally, a set of mes-
sages provide details on the specific Model
790 and connected Model 780-03 software
versions:
1. Displays 790
2. Displays Model 790’s software version
3. Displays Model 790’s unit address
(A1, A2, A3, or A4)
4. Displays 780
5. Displays Model 780-03’s main software
version
6. Displays FPgA
7. Displays Model 780-03’s logic device
(FPGA) software version