Issue 2, December 2013
Model 42A User Guide
Page 8
Studio Technologies, Inc.
Models 32A, 33A, and 34 listen-only belt-
packs and Model 200-Series announcer
console products from Studio Technolo-
gies. The 30-series units offer a range of
features while providing excellent audio
performance. The 200-series units com-
bine a variety of microphone control,
headphone monitoring, IFB and intercom
system interfacing, and related functions
into compact desktop units. Legacy
listen-only beltpacks from RTS, including
the 4020 and 4030, can also be directly
supported.
Alternate Applications
In addition to broadcast intercom applica-
tions, the Model 42A can be used to cre-
ate high-performance stereo headphone
cue systems. Line-level signals coming
from an audio console, a routing switcher,
or an off-air receiver can be connected
to the Model 42A’s audio inputs. The IFB
outputs can be connected to listen-only
beltpacks, several models of which are
available from Studio Technologies. For
example, the Model 35 Talent Amplifier
will allow one or two pairs of stereo
headphones to be supported. Each of
the Model 42A’s four IFB output circuits
will support up to six Model 35 Talent
Amplifiers.
Installation
In this section you will be installing and
interconnecting the Model 42A. The one-
rack-space unit will be mounted in
an equipment rack. Audio input connec-
tions will be made by way of a 25-pin
D-subminiature connector. IFB outputs
will be interfaced using four 3-pin XLR
connectors. AC mains power will be
connected by means of a detachable
cord that is compatible with the Model
42A’s 3-pin IEC 320 C14 inlet connector.
System Components
The shipping carton contains the Model
42A Interface and associated user guide.
Units are also supplied with an AC mains
cord that has a North-American (NEMA
5-15P) standard plug on one end and an
IEC 320 C13 connector on the other end.
Units bound for other destinations may
require a different cord set; your dealer
or distributor should provide one.
Locating the Model 42A
The Model 42A’s IFB outputs provide DC
power and unbalanced audio to operate
external IFB user devices. These devices
are often IFB “beltpacks,” broadcast
announcer consoles, or other “talkback
boxes.” The Model 42A’s mounting loca-
tion will dictate the length of the cable
runs needed to link the unit with the con-
nected devices. In some cases the loca-
tion choice is already established. For
example, in mobile broadcast applica-
tions the Model 42A will almost always be
located in a production truck or trailer. But
in fixed applications it may be possible to
select the Model 42A’s mounting location
so as to minimize cable length. In general,
shorter cables will lead to more reliable
and consistent system performance. It’s
also helpful if a technician can readily view
and access the monitor section that is lo-
cated on the right side of the Model 42A’s
front panel. The output status LEDs and
levels meters can serve important roles
in ensuring correct IFB output operation.
Access to the headphone output jack and
level control can also be useful.
