Studio Technologies 74 - Manual (Page 5)

Issue 2, January 2006 Model 74/75 User Guide
Page 6 Studio Technologies, Inc.
for Surround
Figure 1. Model 74 Central Controller Front Panel
Power
present LED
Data
active LED
Stereo
Input A
trim pots
Surround
Input A
trim pots
Surround
Input B
trim pots
Stereo
Input B
trim pots
Figure 2. Model 74 Central Controller Back Panel
To/from
Model 75
Control
Console
AC mains
input connection
Remote
control
inputs
Surround Input B
and Stereo Input B
connections
Output to
Model 35
Talent
Amplifi ers
Monitor B output
and line-level
talkback input
Monitor A output and
line-level cue audio
outputs
Surround Input A
and Stereo Input A
connections
Infrared
receiver
input
The Model 74 provides two 6-channel
monitor outputs. A powerful system feature
is the ability to confi gure the monitor out-
puts to meet the exact needs of an instal-
lation. In a “straight-ahead” application
the monitor outputs might be confi gured
to support two independent surround (5.1)
loudspeaker systems. Alternately, one
surround and one stereo monitor system
could be connected. However, other more
unique confi gurations are also possible.
These include supporting alternate sur-
round monitor speaker systems or adding
additional LFE or surround speakers. The
monitor outputs are electronically balanced
and designed for connection to audio pow-
er amplifi ers or amplifi ed loudspeakers.
Protection circuitry provides power-up and
power-down protection of the connected
loudspeaker systems.
Audio input and output connections are
made using four 25-pin D-subminiature
connectors. The Model 74’s audio path
features low-noise, low-distortion analog
switches for input source selection and
laser-trimmed voltage-controlled-amplifi er
(VCA) integrated circuits for monitor level
control. One 9-pin D-subminiature con-
nector is used to connect the Model 74 to
the Model 75 Control Console. A second
9-pin “D-sub” connector is used to inter-
face remote control signals with the Model
74. The Model 74’s talent amplifi er output
uses a 3-pin male XLR-type connector. An
infrared receiver module can connect to
the Model 74 using a 3.5 mm jack.
An advanced 8-bit microcontroller provides
the logic “horsepower” for the Model 74.
AC mains power is connected directly to
the Model 74, which is factory selected
for 100, 120, or 220/240 V operation.
The internal power supply utilizes two
toroidal mains transformers for quiet
audio operation.