Studio Technologies 74 - Manual (Page 9)

Issue 2, January 2006 Model 74/75 User Guide
Page 10 Studio Technologies, Inc.
for Surround
System Components
The shipping carton contains one each of
the following: Model 74 Central Controller,
Model 75 Control Console, 9-pin D-sub
interconnecting cable, and user guide.
Units destined for North America also
include an AC mains cord. Your dealer or
distributor will provide an AC mains cord
for non-North American destination. Model
35 Talent Amplifi ers will be contained in
separate cartons.
Mounting the Model 74
The Model 74 Central Controller requires
one space in a standard 19-inch equip-
ment rack. Select a location that is conve-
nient to both the analog audio signals and
the Model 75 Control Console. A cable
is provided to connect the Model 75 with
the Model 74. Secure the Model 74 into
the equipment rack using two mounting
screws per side.
Audio Connections
Line-level audio signal connections are
made by way of four 25-pin D-sub connec-
tors, located on the Model 74’s back panel.
To implement all the available features
four cable harnesses, each with a 25-pin
D-sub plug (male) on one end and the
desired connectors on the other end, are
necessary. These cable harnesses are not
supplied by Studio Technologies. Note that
our friends in some locations may use the
term “loom” instead of harness.
The wiring scheme used by the D-sub
connectors comply with that made familiar
by TASCAM® with their DA-88® product.
Wiring harnesses prepared for connect-
ing to the Model 74’s surround and stereo
inputs are identical to DA-88-style input
harnesses. A wiring harness prepared for
the monitor output A and line-level cue
outputs is identical to that of a DA-88-style
output harness. A wiring harness prepared
for the fourth D-sub is slightly different. It is
used for connecting with the six channels
of monitor output B as well as the line-
level talkback input. As such, it will require
careful attention when selecting the right
terminations, e.g., six male plugs and one
female connector. Please refer to Figures
6 through 11 for the exact connection de-
tails. Be certain to note that the Model 74’s
D-sub connectors use 4-40 threads.
Unless there’s a special need, it may be
cost and time effective for you to purchase
commercially made cable harnesses. Let
the large market for DA-88-style cabling
help you painlessly install your system!
There is one caveat to using pre-made
harnesses. The sex of the connector
associated with the line-level talkback
input may need to be changed. Even so,
using pre-made cables harnesses may
still provide helpful.
Surround and Stereo Inputs
The connector labeled Surround Input A
and Stereo Input A, as well as the
connector labeled Surround Input B and
Stereo Input B are used to interface with
the two 6-channel (5.1 surround) and two
2-channel (stereo) input circuits. Please
refer to Figures 6 and 7 for details on the
exact “pin out” of the D-sub connectors.
Each input circuit is electronically balanced
and intended for connection to balanced
or unbalanced sources with nominal sig-
nal levels of –12 dBV to +6 dBu. A 15-turn
trim potentiometer is associated with each
input channel, allowing the input sensitivity
to be adjusted to match the source’s level.
The confi guration section of this guide pro-
vides details on using the trim pots.