Studio Technologies 742A - Manual (Page 6)

Issue 1, July 2012 Model 742A User Guide
Page 6 Studio Technologies, Inc.
Audio Mixer
for worldwide use, the input voltage can
range from 100 to 240 volts, 50/60 Hz. A
source of 10 to 18 volts DC can also be
connected to power the Model 742A. If
both AC and DC sources are connected,
the AC source will power the unit while the
DC source will serve as a backup. In this
way a battery can be connected, ready to
serve in a standby capacity.
A carefully selected feature set ensures
that the Model 742A will be a “team
player” when it is integrated into an audio
system. A number of internal configuration
“jumpers” allow the unit’s performance
to be tailored to the needs of specific
installations. And while there’s flexibility on
the inside, the operator is presented with
an easy-to-use set of front-panel controls
and indicators—the operator typically
never has to access the back panel to
operate the unit. In this way the goal of
delivering successful on-air and produc-
tion audio, day-after-day, can best be
achieved. The Model 742A’s audio quality
is “pro” throughout. The components were
carefully selected to deliver low-noise, low-
distortion performance.
Long-term reliability was also part of the
Model 742A’s design criteria. To that end
the unit’s enclosure is made of lightweight
yet rugged aluminum with a steel front
panel for overall rigidity which adds to
rack-mounting stability. On the inside,
a conservative circuit design combines
state-of-the-art integrated circuits for sonic
quality with numerous filtering and protec-
tion components for long-term reliability.
System Features
Mic/Line Inputs
Four input channels are provided for con-
nection to microphone or line-level sig-
nals. The electronically balanced circuitry
is “ruggedized” for reliable operation
under tough operating conditions. The
low-noise, low-distortion, high-headroom
audio performance is what’s expected
of sophisticated “pro audio” equipment.
Features provided for each input channel
include an input sensitivity button, rotary
level control, signal level status LED, and
output bus assignment switch. To support
condenser microphones, the four mic/line
inputs can be individually configured to
supply 48 volt phantom power. Four DIP
switches, accessible on the back panel,
allow individual channel phantom power
on/off control.
For ease of use, each input’s rotary level
control sets the gain of the input circuit as
well as the level being sent to the selected
main output bus (or buses). For conve-
nience the input sensitivity button, as with
the other Model 742A operator controls,
is located on the front panel. For operator
assistance, a dual-color level status LED
provides signal present and peak level
indication.
Associated with each mic/line input chan-
nel is a 3-position output bus assignment
switch. This allows each input to be as-
signed to bus 1, bus 2, or both, quickly
creating two fully independent audio
“feeds.” Bus assignment switches, rather
than the more-typical “pan pots,” were
specifically selected for the Model 742A’s
design. This allows a more positive as-
signment of an input source to the desired