Studio Technologies M212-00151 - Manual (Page 8)

Model 212 User Guide Issue 2, June 2006
Studio Technologies, Inc. Page 9
control modes can be configured so that a
minimum headphone output level is main-
tained. Alternately, the headphone output
can be set to fully mute when the controls
are at their minimum position. The rotary
controls can also be set for a reverse
left/right mode. This is provided for cases
where a user needs to wear their headset
“reversed” to support alternate camera
angles. By using this special mode intui-
tive operation will be maintained and a
comfortable work environment assured.
Provision has been made to support ap-
plications where a monaural cue feed is
desired. A configuration switch allows the
summing (combining) of the selected left
and right headphone sources. In addition
to creating a dual-channel mono output it
also allows the level controls to be config-
ured as a simple 2-channel mixer.
The headphone output was designed to
meet the needs of contemporary head-
phones and headsets. Specifically, the
output circuits act as voltage, rather than
power, drivers. In this configuration they
can provide high output levels with very
low distortion and noise, along with mini-
mal current consumption. The output cir-
cuits are configured to safely drive stereo
or mono loads. This ensures that all types
of headphones, headsets, and earpieces
can be directly connected.
Audio Quality and Protection
The Model 212’s circuitry was carefully
tailored to provide excellent audio perfor-
mance. Professional-quality components
are featured throughout. For reliability all
audio routing is performed using solid-
state devices. In all critical audio paths,
“clickless” performance is provided. All
audio inputs and outputs make extensive
use of protection components. This lim-
its the chance of damage from ESD and
other undesirable, yet real-world, hazards.
Power Sources
The Model 212 requires an external source
of nominal 24 volt DC, 150 milliamperes
maximum, for operation. An external pow-
er supply is included with each unit. Inside
the Model 212, an internal switch-mode
power supply creates the various voltage
“rails” required by the internal circuitry.
As an alternative, the Model 44 Interface
can be used to power the Model 212.
Available from Studio Technologies, it
serves as an interconnection “hub,” pro-
viding power and signal routing for up
to six Model 212 Announcer’s Consoles.
Refer to the Technical Notes section for
details.
Auxiliary Relay
Model 212 resources include a general-
purpose relay, allowing specialized con-
figurations to be created. Under software
control, the relay can be configured to
follow the state of the main and talkback
audio channels. Taking advantage of the
back-panel locations provided for addi-
tional XLR-type connectors, a technician
may easily implement a variety of func-
tions such as providing an “on-air” indi-
cator or performing loudspeaker muting
during talkback. The auxiliary relay is also
used by the optional direct microphone
output card.
Configuration
Model 212 configurations are made
using a number of DIP-type switches. One
8-position switch array is used to set the
gain of the microphone preamplifier, the