Studio Technologies 47 - Manual (Page 10)

Issue 1, August 2010 Model 47 User Guide
Page 10 Studio Technologies, Inc.
typically connected to 2-wire party-line in-
tercom circuits. But power on both pins 2
and 3 of each interface was necessary for
compatibility with SAP panel applications.
By adding two DC power sources to each
of the Model 47’s 2-wire interfaces, the
need for external intercom power supplies
could often be eliminated.
The final step was to create a physical
package that would provide significant
resources in a form that allowed simple
and reliable integration with other equip-
ment. This was accomplished by including
two 2-channel interfaces in a 1U enclo-
sure. Using standard 3-pin XLR audio
connectors would enable rapid installation
and troubleshooting. And by making the
Model 47 “universally” powered, installa-
tion in any locale could be directly
supported.
Installation
In this section you will be installing and
interconnecting the Model 47. The one-
rack-space unit will be mounted in an
equipment rack. Audio input, audio out-
put, and party-line intercom connections
will be made by way of 3-pin XLR connec-
tors. AC mains power will be connected
by means of a detachable cord set that is
compatible with the Model 47’s 3-pin IEC
320 C14 inlet connector.
System Components
The shipping carton contains the Model
47 Interface, user guide, and AC mains
cord suitable for use in North America and
Japan. Your dealer or distributor should
provide an AC mains cord appropriate for
use in other locations.
Locating the Model 47
The Model 47’s mounting location will
dictate the length of the cable runs needed
to link the unit with the connected devices.
This is really only a factor in relation to the
2-wire party-line intercom circuits. These
circuits carry unbalanced audio which can
be susceptible to interference and cross-
talk issues. Intercom circuits also carry DC
power which may make resistive losses
come into the picture. In general, shorter
intercom cable lengths will assure more re-
liable and consistent system performance.
Another location criterion is access to the
Model 47’s front panel. An optimal location
will allow convenient use of the auto null
pushbuttons and easy observation of the
status and level meter LEDs.
Mounting the Model 47
Once a mounting location has been
selected installation can begin. The Model
47 requires one space (1.75 vertical inches)
in a standard 19-inch (48.3 cm) equipment
rack. Secure the unit into the equipment
rack using two mounting screws per side.
4-Wire Audio Inputs and
Outputs
Two audio line input and two audio line
output signals are associated with the
4-wire section of each of the Model 47’s
two interface circuits. Connections are
made using standard 3-pin male and
female XLR connectors. Refer to Appendi-
ces A, B, and C for details on interconnect-
ing with RTS, Riedel, and Clear-Com matrix
intercom systems.