Studio Technologies 230 2008 - Manual (Page 9)

Model 230 User Guide Issue 7, October 2008
Studio Technologies, Inc. Page 9
A headphone control reverse mode is
provided specifically for on-air television
applications where a headset with boom
microphone is used. The reverse mode
ensures that no matter which headset ori-
entation is used by the talent, the controls
will always work intuitively. This results in
a comfortable work environment, allow-
ing the left control to impact the level to
the talent’s left ear while the right control
impacts the right.
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 ad-
dition to creating a dual-channel mono
output it also allows the level controls
to be configured as a simple 2-channel
mixer. For applications where a single
“muff” headset or IFB-type earpiece is
connected, another configuration switch
can be used to disable the headphone
output’s right channel.
The headphone output is optimized 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.
Intercom Interface
Of special note is the Model 230’s sophis-
ticated intercom interface. It’s designed
to work correctly with industry-standard
single- and dual-channel party-line inter-
com systems, including those from RTS
and Clear-Com. An intercom line con-
nected to the Model 230 can serve three
functions: providing cue audio signals to
the headphone output, allowing talkback
audio to be sent to intercom users, and as
a Model 230 power source. Audio signals
present on the single- or dual-channel
intercom line can be flexibly routed to the
headphone output. Talkback audio can
be sent to either or both intercom chan-
nels. Trim potentiometers, located on the
bottom of the unit, allow adjustment of the
talkback-to-intercom null (“sidetone”) level.
Other announcer console products can
exhibit talkback-to-intercom-related audio
oscillations (“squeals”) that end up in
the headphone output. A special Model
230 feature ensures that this will never
occur. This is accomplished by means
of a special “auto-terminate” circuit that
becomes active whenever an intercom
line is not connected to the Model 230.
Active Sidetone Function
The Model 230 includes a unique active
sidetone function that’s available whenever
the unit is configured for one of the two
production modes. By routing audio from
the microphone input to the headphone
output a user confidence (“sidetone”)
signal is provided. This allows a user to
always hear what they are saying, a critical
requirement for effective communications.
The word “active” is part of the function’s
name because it involves active circuitry,
under software control, to achieve excellent
audio performance. The sidetone level is
dynamically configurable, allowing the user
to adjust the level as required.
Audio Quality and Protection
The Model 230’s circuitry is carefully
tailored to provide excellent audio perfor-
mance. Professional-quality components