Studio Technologies 770 - Manual (Page 20)

Issue 1, October 1997 Model 770 User Guide
Page 20 Studio Technologies, Inc.
Model 770
Monitor Section
External Monitor Inputs
Two external audio signals can be con-
nected, allowing them to be monitored
independently of the internal audio sig-
nals. It is intended that the external moni-
tor inputs will be connected to outputs
associated with off-air, microwave, or
satellite receivers. The inputs are monau-
ral, electronically balanced, have a nomi-
nal level of +4dBu, and interface using
¼-inch 3-conductor phone jacks.
Prepare the mating connectors (plugs)
so that tip is signal high (+ or hot), ring is
low (– or cold), and sleeve is shield. With
an unbalanced source connect the plug’s
tip to high (+ or hot), and both the ring
and sleeve to shield. If connecting to an
unbalanced source in this manner results
in hum or noise, connect tip to high (+ or
hot) and ring to shield; leave the sleeve
unterminated.
Monitor Output
The monitor output is designed for con-
nection to an audio power amplifier asso-
ciated with a monitor loudspeaker. In
mobile applications it may prove common
for a loudspeaker with an internal ampli-
fier, such as from Fostex, to be connected
to the Model 770’s monitor output. The
output is electronically balanced, line-level,
and can drive a balanced or unbalanced
load of 600 ohms or greater.
The monitor output utilizes a ¼-inch
3-conductor phone jack for interconnec-
tion. Prepare the mating connector (plug)
so that tip is signal high (+ or hot), ring is
low (– or cold), and sleeve is shield. To
connect to an unbalanced load connect
the plug’s tip to high (+ or hot), and both
the ring and sleeve to shield. Whether this
output is wired via a patch bay will depend
on the specific installation.
1kHz Direct Output
Direct access to a continuous 1kHz tone
signal is provided by means of a line-level
output. As one of the unique features of
the Model 770, it should definitely be
utilized! This output is intended to be
connected to the audio input associated
with a video/audio 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 accessed for test and calibration
purposes.
The electronically balanced, nominal
+4dBu output is accessible via a ¼-inch
3-conductor phone jack. The circuitry is
capable of driving a balanced or unbal-
anced load of 600 ohms or greater.
Prepare the mating connector (plug) so
that tip is signal high (+ or hot), ring is
low (– or cold), and sleeve is shield. To
connect to an unbalanced load connect
the tip to high (+ or hot), and both the
ring and sleeve to shield.
A trim potentiometer is used to set the
precise output level of the 1kHz direct
output. Refer to the Configuration section
of this guide for details.
Connecting AC Mains Power
The Model 770 is factory configured to
operate from AC mains power of either
100, 120, or 220/240V, 50/60Hz. In most
cases, units shipped to North America are
factory configured for 120V operation
and are supplied with an internal 0.2A,
5 x 20mm fast-acting fuse. Units config-
ured for 100V also utilize a 0.2A fuse.