Studio Technologies 34 - Manual (Page 4)

Issue 1, August 2005 Model 34 User Guide
Page 4 Studio Technologies, Inc.
Model 34
Talent Amplifier
a factor in IFB or intercom systems, the
Model 34 is built to “pro audio” standards.
This helps to ensure that the best possible
audio reproduction is provided.
The Model 34 is compatible with virtually
every standard broadcast IFB and party-
line intercom circuit. This type of circuit
typically uses 3-pin XLR-type connectors
for interfacing with connected equip-
ment. XLR pin 1 serves as common for
DC power and audio. Pin 2 provides DC
power and, in the case of a dual-channel
circuit, DC power and channel 1 audio.
Pin 3 provides channel 2 audio in dual-
channel systems or channel 1 audio in
single-channel systems.
Model 34 units have been tested for
correct operation with IFB and intercom
circuits associated with systems from
RTS™/Telex®, Clear-Com®, and Studio
Technologies. Good performance can be
expected when the Model 34 is used with
IFB circuits associated with the ubiquitous
RTS Model 4010 Central Controller and
IFB-828 Interface. With IFB circuits provid-
ed by interface units from Studio Technol-
ogies, excellent audio quality and support
for lengthy cable runs can be expected.
Connection and
Operation
As expected, connecting and using
the Model 34 is quite simple. The IFB or
party-line intercom circuit that is going to
provide the unit’s power and audio signals
is connected to the Model 34’s 3-pin
female XLR-type connector. It is located
on the back panel and labeled INPUT. The
cabling associated with the IFB or inter-
com circuit must conform to the broadcast
standard. With dual-channel circuits pin 1
serves as common for power and audio,
pin 2 has positive DC with channel 1 audio
superimposed on it, and pin 3 has chan-
nel 2 audio. With the less-common single
channel IFB or intercom circuits, pin 2
will have power only while pin 3 will have
channel 1 audio. Upon connecting the IFB
or intercom circuit the power-present LED,
located on the front panel, will light.
Virtually any pair of headphones, head-
sets, or earpieces can be connected
to the Model 34’s audio outputs. For
convenience both ¼-inch and 3.5 mm
3-conductor (“stereo”) jacks are provided.
The jacks, located on the back panel, are
internally connected in parallel (“multed”)
with the same circuitry driving both. Devic-
es that use monaural (2-conductor) or ste-
reo (3-conductor) plugs can be connected
into either jack without impacting the unit’s
performance. Protection resistors, electri-
cally in series with the left and right output
circuitry, prevent damage when mono
(2-conductor) plugs are inserted.
Level Controls and Output
Mode Select Switch
Two rotary level controls and a 2-position
output mode select switch are located
on the Model 34’s front panel. How the
controls and switch function depends on
the type of IFB or intercom circuit that’s
been connected to the unit, as well as the
specific type of headset or earpiece being
used. The main variables are whether the
IFB or intercom audio source is dual- or
single-channel, and if the connected trans-
ducer uses a monaural (2-conductor) or
stereo (3-conductor) plug.