Studio Technologies 770 - Manual (Page 32)

Issue 1, October 1997 Model 770 User Guide
Page 32 Studio Technologies, Inc.
Model 770
whenever energy in the voice band is
present with sufficient level. “Clickless”
electronic switches control the routing
of program and audio signals to the IFB
output.
With the Model 770 any of seven audio
sources can be assigned as a program
or interrupt audio source; mixer main bus
audio, mixer AUX bus audio, IFB line
inputs 1-4, and telco interface receive
audio. Any signal assigned as program
audio will be connected to the IFB output
whenever there is no signal present on the
interrupt bus. If voice energy is detected
on the interrupt bus, it is connected to the
IFB output, and the program audio signal
is muted or dimmed. Once voice audio is
no longer present on the interrupt bus, the
interrupt bus is disconnected from the IFB
output and the program bus is again
connected.
Semantics are what leads to the confusion
when learning to use the Model 770. When
users start describing the actual signals
that will be presented to the IFB section,
all clarity seems to disappear! On the
Model 770, how does a user assign a
signal to give the desire cueing perfor-
mance? First lets start with some ex-
amples of audio signals that may be
encountered. It is common for an “inter-
rupt” signal to originate from a control
room located in a major city, such as
New York. This may be a program or mix-
minus signal that gets interrupted in the
aforementioned control room. It’s really a
combination of program and interrupt. In
a second example a program signal may
come from an off-air receiver, with no
cues present. A third example could be
the output of a 2-way radio that a director
is using to “cue” the talent.
The best way to determine whether these
signals should be assigned as program
or interrupt is to decide what you want to
do with them, as related to the IFB output.
Decide if each signal must always to be
heard by the talent, or if another signal
needs to have priority over it. Signals that
must have priority over others need to be
assigned as interrupt audio. Signals that
need to be muted (or dimmed) when other
signals are active, should be assigned as
program audio. Signals that neither have
priority or are subservient to others should
be assigned as program.
Figure 13. Detail of front panel showing IFB
line inputs