Studio Technologies 770 - Manual (Page 13)

Model 770 User Guide Issue 1, October 1997
Studio Technologies, Inc. Page 13
Model 770
Main Output 4
Main Output 4 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
Main Output 4 be wired, via a patch bay,
to the vehicle’s input/output connector
panel.
Main Output 4 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, Main Output 4 will provide its full
specified performance.
AUX Outputs—General Information
The Model 770 contains two outputs
associated with the AUX audio bus. AUX
Output 1 is electronically balanced, has a
nominal level of +4dBu, and is capable of
driving balanced or unbalanced loads of
600 ohms or greater. AUX Output 2 is
transformer balanced, with a nominal level
of +4dBu. It is capable of driving full level
into a balanced or unbalanced load of 2k
ohms or greater.
AUX Output 1
AUX Output 1 is intended for connection
to devices located only within the vehicle.
The output utilizes a ¼-inch 3-conductor
phone jack for interconnection. Prepare
the mating connector (plug) so that tip is
signal high (+ or hot), ring is low (– or
cold), and sleeve is shield. This output
Note: While the electronically balanced
output circuits are capable of driving
loads of 600 ohms or greater, the out-
put level will drop slightly as the load
impedance approaches 600 ohms. A
0.5dB difference in output level can
be expected as the load impedance
changes from 10k ohms to 600 ohms.
This applies to all of the electronically
balanced output circuits provided on
the Model 770.
Main Output 4 is transformer balanced,
with a nominal level of +4dBu. It is ca-
pable of driving full level into a balanced
or unbalanced load of 2k ohms or greater.
Main Outputs 1, 2, and 3
Main Outputs 1, 2, and 3 are intended for
connection only to devices located within
the vehicle. It is recommended that either
Main Output 1, 2, or 3 be used as the “on-
air” source. Each output utilizes a ¼-inch
3-conductor phone jack for interconnec-
tion. Prepare the mating connectors
(plugs) so that tip is signal high (+ or hot),
ring is low (– or cold), and sleeve is shield.
Whether these outputs are wired via a
patch bay will depend on the specific
installation.
While balanced operation is preferred,
unbalanced operation is not a problem
for the output circuitry. To connect to an
unbalanced load connect the tip to high
(+ or hot), and both the ring and sleeve
to shield. For optimal unbalanced opera-
tion, it is important to connect both ring
and sleeve together directly on the plug
that mates with the Model 770, and not at
the other end of the cable.