Studio Technologies IFB Plus 2001 - Manual (Page 8)

Issue 7, November 2001 Model 2 User Guide
Page 8 Studio Technologies, Inc.
level controls, along with a source select
switch, allows camera and production
personnel to hear IFB cues from either
or both channels. This allows IFB signals
intended for both technician and talent
to be simultaneously monitored.
Model 2 Central Controller
Contained in a single rack space unit is
everything required to implement a two-
channel IFB system. Features include
multiple program inputs, telephone inter-
faces, voice-operated (VOX) interrupt,
level meters, monitor amplifier, and inter-
nal interrupt microphone. Up to four
Model 22 Access Stations can be con-
nected to the Model 2, allowing producer
or director positions to access the IFB
channels. In addition, up to four Model 32
or Model 33 Talent Amplifiers can be
connected to a Model 2. The Model 32
and 33 allow personnel access to the IFB
channels using a single standard micro-
phone cable.
The Model 2 packs numerous features
into a single, 19-inch rack space.
Standard connectors are used through-
out, including 3-pin XLR-type, ¼-inch
2-conductor, 9-position D-subminiature,
and modular telephone (RJ11-type)
jacks. Power is supplied by standard
120 or 220/240V (factory configured),
50/60Hz via a detachable cord.
IFB Channels
The Model 2 contains two independent
IFB channels. Each channel has individual
controls and indicators, including program
source select switches, program level
control, 5-segment LED level meter, and
LED status indicators. We’ll describe one
channel in this paragraph. Six switches
allow the four program inputs and incom-
ing audio from the two telephone inter-
faces to be selected as program audio.
A level control allows adjustment of the
program audio level relative to the fixed
interrupt audio level. A 5-segment LED
level meter displays the composite IFB
channel audio level, i.e., program and
interrupt audio level. The meter facilitates
the rapid setting of the program level
control, as well as providing a general
indication of the channel’s signal level.
Each channel’s composite IFB audio
signal (program and interrupt audio) is
sent to four places: line output, talent
amplifier output, telephone interface 2,
and monitor amplifier. The line outputs
provide electronically balanced, line-level
signals that interface with external equip-
ment via two XLR-type connectors. The
talent amplifier output provides channel 1
and 2 audio, along with +18Vdc power
on one 3-pin XLR-type connector. Any
combination of up to four Model 32 or 33s
can be connected to the talent amplifier
output.
Program Inputs
The Model 2 contains four program inputs.
Each can be individually assigned to the
two IFB channels, with the ability to assign
multiple program inputs to an IFB channel.
Program signals enter the unit via four
XLR-type connectors on the back panel.
The program inputs are electronically
balanced with a nominal input impedance
of 24k ohms. They feature low noise, low
distortion, and high common mode signal
rejection. Each program input has a trim
potentiometer associated with it. The trim
pots, accessible from the back panel,
allow the nominal +4dBu input level to
be adjusted over a ±8dB range.