Studio Technologies 230 2008 - Manual (Page 16)

Issue 7, October 2008 Model 230 User Guide
Page 16 Studio Technologies, Inc.
connected to the line inputs by way of
3-pin female XLR-type connectors which
are located on the unit’s back panel.
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. If
connecting a source in this manner results
in hum or noise, it’s possible that remov-
ing the shield connection from pin 1 can
eliminate the issue. With an unbalanced
source connect pin 2 to signal high (+
or hot) and both pins 1 and 3 to shield. If
connecting 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.
Intercom Interface
The Model 230’s intercom interface is
designed to directly connect with standard
single- and dual-channel party-line inter-
com lines. The one or two audio signals
provided by the intercom line can serve
as audio sources for the headphone
outputs. Each signal can be individually
assigned to the left channel, the right
channel, or both the left and right chan-
nels. The Model 230 can be configured
to send talkback audio to either or both
of the intercom channels. In addition, the
intercom line can also provide the DC
power required to operate the Model 230’s
circuitry.
The intercom line is connected to the
Model 230 by way of a 3-pin female XLR-
type connector which is located on the
back panel. The mating connector (male)
should be wired so that common is on
pin 1, DC with channel 1 audio is on pin
2, and channel 2 audio is on pin 3. With
single-channel intercom lines common is
on pin 1, DC power is on pin 2, and audio
is connected to pin 3.
The Model 230’s intercom interface is
directly compatible with broadcast and
production party-line intercom lines as-
sociated with systems from manufactures
such as RTS and Clear-Com. Intercom
lines associated with other systems
should be equally compatible. RTS TW
series systems are normally interfaced
using 3-pin XLR-type connectors. These
connectors are wired with common on
pin 1, DC power and channel 1 audio on
pin 2, and channel 2 audio on pin 3. With
many Clear-Com systems, common is on
pin 1, DC power is provided on pin 2, and
audio is provided on pin 3.
The DC power supplied by the connected
intercom line is generally sufficient to
operate the Model 230’s circuitry. The
acceptable input range is 24 to 32 volts,
with a required current of 125 milliam-
peres. Note that the specified input volt-
age is given when measured directly at
the Model 230’s intercom connector, not
at the source of the intercom line.
External Power Input
An external source of 24 volt DC power
can be connected to the Model 230 by
way of a 2.1 x 5.5 mm coaxial power jack
which is located on the back panel of
the unit. The center pin of the jack is the
positive (+) connection. While the require-
ment for the external source is nominally
24 volts, correct operation will take place
over a 20 to 30 volt range. The Model 230
requires 90 milliamperes at 24 volts DC
for correct operation. Included with each
Model 230 is a 24 volt DC external power
supply. The power supply’s DC output
cable has been terminated with a Switch-
craft® S760K coaxial power plug. This
“locking” type of plug correctly mates
with the Model 230’s 24 Vdc input jack.
The locking feature is important, allowing