Studio Technologies 742A - Manual (Page 12)

Issue 1, July 2012 Model 742A User Guide
Page 12 Studio Technologies, Inc.
Audio Mixer
inputs not be wired by way of points on
an audio patch bay. It certainly can be
done, but the possibility for intermittent
connections, especially in mobile applica-
tions, may significantly increase.
Line Inputs
The Model 742A contains four line-level
input channels. (Refer to Figure 4 for a
detailed view.) Each input uses a 3-pin
female XLR connector. Prepare the mating
connectors (males) so that pin 2 is signal
high (+ or hot), pin 3 is low (– or cold),
and pin 1 is shield. Unbalanced signals
can also be connected. In this case, pin
2 is connected to signal high (+ or hot),
and pins 1 and 3 are connected to shield.
If this results in hum or other noise being
present, try connecting pin 2 to signal high
and shield to pin 3; leave pin 1 unconnect-
ed (“floating”). To provide maximum flex-
ibility, it is recommended that the signals
connected to the line inputs be wired by
way of points on an audio patch bay.
Main Outputs
The Model 742A contains two main out-
puts which are directly associated with
output buses 1 and 2. (Refer to Figure 5
for a detailed view.) They are electronically
balanced, capacitor coupled, with a nomi-
nal level of +4 dBu. The output circuitry
is capable of driving balanced or unbal-
anced loads of 600 ohms or greater. Note,
however, that as the load impedance
approaches 600 ohms the output levels
Figure 4. Detail of back panel showing line input connectors
Figure 3. Detail of back panel showing mic/line input connectors