Studio Technologies 230 2014 - Manual (Page 9)

Model 230 User Guide Issue 9, November 2014
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 addition
to creating a dual-channel mono output
it also allows the level controls to be con-
figured as a simple 2-channel mixer. For
applications where a single “muff” headset
or IFB earpiece is connected, another con-
figuration 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 party-line intercom interface. It’s
designed to work correctly with industry-
standard single- and dual-channel party-
line intercom systems, including those
from RTS and Clear-Com. An intercom
line connected to the Model 230 can
serve three functions: providing cue audio
signals to the headphone output, allow-
ing 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. Talk-
back audio can be sent to either or both
intercom channels. Trim potentiometers,
located on the bottom of the unit, allow
adjustment of the talkback-to-intercom
null (“sidetone”) level.
The ability to listen to one or both pins
of a connected intercom circuit will only
be available when the intercom interface
circuit detects DC voltage on pin 2. This
feature minimizes the chance that ob-
jectionable audio content (i.e., “howls”
or “squeals”) will be routed to the head-
phone output when an intercom circuit
is not connected.
Sidetone Function
The Model 230 includes a sidetone func-
tion that routes audio from the micro-
phone input to the headphone output as a
user confidence signal. This allows a user
to always hear what they are saying, a crit-
ical requirement for effective communica-
tions. The sidetone level can be adjusted
using one of the front panel level controls,
allowing the user to set it as required for
effective use.
Audio Quality and Protection
The Model 230’s circuitry is 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 under microcontroller direc-
tion. In all critical audio paths, “clickless”
electronic switches provide noise-free