Studio Technologies 200 - Manual (Page 6)

Model 200 User Guide Issue 3, August 2004
Studio Technologies, Inc. Page 7
channel source. Channel 2 (pin 3 of the
IFB connector) serves as the source for
the headphone’s right channel output.
Some applications may benefit by being
able to connect standard line-level audio
signals to the Model 200. To meet this
need one or two optional line input cards
can be installed in the unit’s back panel.
Each card provides a 3-pin female XLR-
type connector and transformer-isolated
+4 dBu nominal input circuit. One card
is assigned to the left headphone output,
the other to the right.
Two rotary controls are provided for user
adjustment of the headphone output
levels. They provide independent volume-
control adjustment of the left and right
channels. To help minimize the chance of
broadcast cues being missed, both level
controls are configured so that a minimum
headphone output level is maintained.
The headphone output was designed
to meet the needs of contemporary
headphones and headsets. Specifically,
the output circuits act as voltage, rather
than power, drivers. This implementation
provides high output levels with very low
distortion and noise, along with minimal
current consumption. The output circuits
can safely drive stereo or mono loads,
ensuring that all types of headphones,
headsets, and earpieces can be directly
connected.
Audio Quality and Protection
The Model 200’s circuitry has been
carefully designed to provide excellent
audio performance. Pro-audio-quality
components are featured throughout. For
reliability all audio switching is performed
using solid-state devices. In the critical
main output and talkback output audio
paths, “clickless” electronic switches
provide noise-free control. All audio inputs
and outputs make extensive use of protec-
tion components. This limits the chance of
damage from ESD and other undesirable,
yet real-world, hazards.
Power Sources
The Model 200 can derive its operating
power from either the IFB input or an ex-
ternal 24 volt DC source. For redundancy,
both power sources can be connected
simultaneously. An internal switch-mode
power supply ensures that all Model 200
features are available, including phantom
power, when powered by either source.
The Model 200 is compatible with IFB
circuits provided by most standard broad-
cast systems. However, maximum perfor-
mance can often be obtained by using the
IFB interface devices available from Studio
Technologies. Single-channel and four-
channel units are available, each providing
high-quality audio along with an excel-
lent source of DC power. They’re directly
compatible with most matrix intercom sys-
tems, as well as standard line-level audio
signals. Refer to the Studio Technologies
website for details.
Connectors
The Model 200 uses standard connec-
tors throughout. The microphone and IFB
inputs use 3-pin female XLR-type connec-
tors. The main and talkback outputs use
3-pin male XLRs. The headphone output
utilizes a ¼-inch 3-conductor jack. The
external source of 24 volt DC power
is connected by way of a 2.1 x 5.5 mm
“locking” coaxial power jack.