Studio Technologies 770 - Manual (Page 8)

Issue 1, October 1997 Model 770 User Guide
Page 8 Studio Technologies, Inc.
Model 770
System Features
Mixer Section
Mic/Line Inputs
Three transformer-coupled input channels
are provided for connection to micro-
phone or line-level signals. The circuitry
is “ruggedized” for reliability under tough
operating conditions. Features provided
for each input channel include selectable
input sensitivity, low-cut filter, and level
control. For operator assistance, a bi-color
LED provides signal present and peak
level indication. Two push-button switches
control the routing of the input signal to
the main and auxiliary (AUX) audio buses.
For convenience the three mic/line input
sensitivity buttons, like all the Model 770’s
operator controls, are located on the front
panel.
Stereo Line Inputs
Two stereo line-level input channels are
provided and are intended for connection
with audio signals associated with video
playback. To support “real world” broad-
cast applications the stereo inputs auto-
matically mix, using individual level con-
trols, to monaural. Two buttons are part of
each input channel, controlling the routing
of the signals to the main and AUX audio
buses.
Main Output
Signals from the mic/line and stereo line
input channels combine to create a mon-
aural signal, called the main output bus. A
studio-quality, limiter/compressor circuit is
provided to control the dynamic range of
the main audio bus. Far from a simple
“clipper,” the limiter/compressor circuit
utilizes a sophisticated laser-trimmed
voltage-controlled amplifier (VCA) inte-
grated circuit for quiet, low-distortion
operation. For installation flexibility, four
output circuits provide access to the main
bus: three are electronically balanced; the
fourth is transformer-balanced.
AUX Output
The Model 770 provides a second monau-
ral audio bus. The AUX bus allows special
applications to be easily supported, such
as creating a “mix-minus” feed or serving
as a second output for on-air use. Signals
from the mic/line and stereo line input
channels section can be assigned to the
AUX bus. Access to the AUX bus is pro-
vided by means of one electronically
balanced and one transformer-balanced
output.
Configurable Outputs
Three monaural, electronically balanced,
line-level outputs are provided and can
serve in a wide range of installation-spe-
cific applications. DIP switches, located
on the back panel, are used to select
from the five available signal sources:
main output, AUX output, IFB output, IFB
program only output, and mic/line input
channel direct. The DIP switches can be
set to provide additional outputs, create
a summed output from the sources, or to
provide direct outputs from the mic/line
input channels.
IFB Section
The IFB section provides an extensive set
of resources to create and maintain one
channel of excellent-quality IFB audio. A
full set of controls and indicators make
operation fast and simple. A front-panel-
mounted gooseneck microphone allows
an operator to make “local” interrupts. IFB