Studio Technologies IFB Plus 2001 - Manual (Page 14)

Issue 7, November 2001 Model 2 User Guide
Page 14 Studio Technologies, Inc.
The auxiliary audio connection is made
via a 3-pin female XLR-type connector on
the back panel. The auxiliary audio input
circuitry is direct coupled, electronically
balanced with an input impedance of 24k
ohms. An external load resistor must be
added if your facility terminates audio
lines. Prepare the mating connector so
that pin 2 is positive (+ or hot), pin 3 is
negative (– or cold), and pin 1 is shield.
With unbalanced signals connect pin 2
to positive, and pins 1 and 3 to shield.
The VOX interrupt function is quite special-
ized and may not be used regularly in
your facility. For maximum flexibility, it may
be best to terminate the auxiliary audio
input to a patch point in the audio patch
bay. In this way, a variety of audio sources
can quickly be selected as the VOX inter-
rupt input source. The VOX feature may
sit unused for months or years, but when
you need it there’s no substitute! The
Model 2’s VOX interrupt works quite well,
better than you may think. (Actually better
than we thought, too, until we tested it!)
Try it out and you may soon find more
applications than you expected.
Talent Amplifier Output
The talent amplifier output is designed to
supply power and audio signals for up to
four Model 32 or 33 Talent Amplifiers. The
talent amplifier output exits the Model 2
via one 3-pin male XLR-type connector.
Pin 1 is common, pin 2 is +18Vdc modu-
lated with channel 1 audio, and pin 3 is
channel 2 audio. For convenience, it is
expected that the talent amplifier output
will be wired to a main distribution panel,
along with microphone, camera, and other
various connections. This will allow easy
talent amplifier connection using standard
flexible microphone cable. The distribution
panel does not need multiple talent ampli-
fier output connectors which are “multed”
from the Model 2’s talent amplifier output.
Each Model 32 and Model 33 Talent
Amplifier has both a female and a male
3-pin XLR-type connector. This allows the
talent amplifier interconnecting cables to
be “looped” through the talent amplifiers.
This will simplify and, in most cases,
reduce the amount of cabling required
to connect multiple talent amplifiers.
Line Outputs
Associated with each of the two IFB
channels is an electronically balanced
line-level output with a nominal signal level
of +4dBu. The line outputs are capable
of driving balanced or unbalanced, low
or high impedance loads. The line outputs
exit the Model 2 via two 3-pin male XLR-
type connectors. Prepare the mating
connectors so that pin 2 is positive (+ or
hot), pin 3 is negative (– or cold), and pin
1 is shield. To connect to an unbalanced
load connect pin 2 to positive (+ or hot)
and pins 1 and 3 to shield.
Some installations may use the line out-
puts to drive wireless IFB transmitters. In
other installations they may be used for
special applications, such as feeding a
satellite uplink. For maximum flexibility it
is recommended that the line outputs be
wired via audio patch points, even if you
have a dedicated application.
The Model 2’s audio quality and flexibility
make it a useful tool for non-IFB applica-
tions. Not to “toot our own horn,” but the
Model 2’s sonic quality is as good as,
if not better than most audio consoles,
tape recorders, etc. As an example, the
frequency response from program input
to line output is better than ±0.5dB from