Studio Technologies 740 - Manual (Page 12)

Issue 3, May 2004 Model 740 User Guide
Page 12 Studio Technologies, Inc.
Model 740
so that pin 2 is signal high (+ or hot), pin
3 is low (– or cold), and pin 1 is shield. To
connect to an unbalanced load connect
pin 2 to high (+ or hot) and both pins 1
and 3 to shield. Whether or not this output
is wired via a patch bay will depend on the
specific installation.
Reference Tone Direct Output
Direct access to a continuous source of
sine-wave reference tone is provided by
means of a line-level output. As one of
the unique features of the Model 740, it
should definitely be utilized! This output
is intended to be connected to the au-
dio input associated with a audio/video
switcher’s “bars and tone” position. For
maximum flexibility, it is recommended
that this signal be routed via a patch bay.
In this way it can be easily accessed for
other test and calibration purposes.
The reference tone direct output is
electronically balanced, has a nominal
+4 dBu level, and is accessible via a
3-pin male XLR-type connector. The
output circuitry is capable of driving a bal-
anced or unbalanced load of 600 ohms
or greater. Prepare the mating connector
(female) so that pin 2 is signal high (+ or
hot), pin 3 is low (– or cold), and pin 1 is
shield. To connect to an unbalanced load
monaural, electronically balanced, and
have a nominal level of +4 dBu. Audio
sources are connected to the external
monitor input’s 3-pin female XLR-type
connectors.
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.
With an unbalanced source connect pin 2
to high (+ or hot) and both pins 1 and 3
to shield. If connecting to an unbalanced
source in this manner results in hum or
noise, connect pin 2 to high (+ or hot) and
pin 3 to shield; leave pin 1 unterminated.
Monitor Output
The monitor output is designed to con-
nect to an audio power amplifier associ-
ated with a monitor loudspeaker. In mobile
applications it’s also popular to use a
loudspeaker with an internal amplifier,
such as those from Fostex. The monitor
output is electronically balanced, capaci-
tor coupled, line level, and can drive a bal-
anced or unbalanced load of 600 ohms or
greater. The nominal output level has been
optimized to match the input sensitivity
typically found on audio amplifiers.
The monitor output utilizes a 3-pin male
XLR-type connector for interconnection.
Prepare the mating connector (female)
Detail of back panel showing monitor output
connector
Detail of back panel showing reference tone
direct output connector, associated level trim
pot, and headphone output jack