Studio Technologies 770 - Manual (Page 14)

Issue 1, October 1997 Model 770 User Guide
Page 14 Studio Technologies, Inc.
Model 770
should be wired via a patch bay to allow
ready access.
While balanced operation is preferred,
unbalanced operation is not a problem
for the output circuit. To connect to an
unbalanced load connect the tip to high
(+ or hot), and both the ring and sleeve to
shield. For optimal unbalanced operation,
it is important to connect both the ring and
sleeve together directly on the plug that
mates with the Model 770, and not at the
other end of the cable.
AUX Output 2
AUX Output 2 has been optimized for
connection to devices located external
to the vehicle. This “ruggedized,” trans-
former-coupled output has a nominal level
of +4dBu. A 3-pin male XLR-type connec-
tor is used for interconnection. Prepare the
mating connector (female) so that pin 2 is
high (+ or hot), pin 3 is low (– or cold),
and pin 1 is shield. It is recommended that
AUX Output 2 be wired, via a patch bay, to
the vehicle’s input/output connector panel.
AUX Output 2 was specifically designed
to provide a fully isolated output with good
sonic performance. It was NOT designed
to drive full level into 600 ohm loads! While
a 600 ohm load can be connected without
damage, a 2dB level drop should be
expected. Used with 2k ohm or greater
loads, AUX Output 2 will provide its full
specified performance.
Configurable Outputs
Each of the three configurable outputs
is electronically balanced, has a nominal
level of +4dBu, and is capable of driving
balanced or unbalanced loads of 600
ohms or greater. The outputs are intended
for connection to devices located only
within the vehicle. DIP switches are associ-
ated with each configurable output. Details
on using these switches can be found in
the Configuration section of this guide.
Each of the configurable outputs is acces-
sible via a ¼-inch 3-conductor phone jack.
Prepare the mating connectors (plugs) so
that tip is signal high (+ or hot), ring is low
(– or cold), and sleeve is shield. To con-
nect to an unbalanced load connect the
tip to high (+ or hot), and both the ring
and sleeve to shield.
It is highly recommended that the config-
urable outputs be routed via a patch bay.
Or, if there are no immediate needs for
these outputs, be certain to terminate
them on a patch bay for future use.
IFB Section
IFB Line Inputs
The Model 770’s IFB section allows four
line-level audio sources to be connected.
These sources can serve as program or
interrupt audio signals, their function being
selectable by the operator using front-
panel controls. The direct-coupled, elec-
tronically balanced input circuitry is
intended for connection to sources lo-
cated within the vehicle. The nominal input
level is +4dBu, but a trim potentiometer
associated with each input gives a ±8dB
input sensitivity range. The Configuration
section of this guide has details on using
the trim pots.
Each of the four IFB line inputs use a
¼-inch 3-conductor phone jack for inter-
connection. Prepare the mating connec-
tors (plugs) so that tip is signal high (+ or
hot), ring is low (– or cold), and sleeve is
shield. With an unbalanced source con-
nect the plug’s tip to high (+ or hot), and