Studio Technologies 220 2004 - Manual (Page 7)

Issue 2, August 2004 Model 220 User Guide
Page 8 Studio Technologies, Inc.
hybrid functions. With these modes the
operation of the main and talkback out-
puts are not impacted. This allows the
talkback 2 button to control the state of
the Model 220’s auxiliary relay, making
specialized implementations possible.
IFB Input
A broadcast-standard “wet” (DC with au-
dio) IFB circuit can be directly connected
to the Model 220’s IFB input. Originated
by sources such as the RTS™ 4000-series
IFB system or IFB interface devices from
Studio Technologies, the connected IFB
circuit can provide DC power to operate
the Model 220 as well as two channels of
cue audio.
Cue Sources
The Model 220 allows up to four audio
sources to be selected for routing to the
headphone output. The sources are IFB
channel 1, IFB channel 2, line input 1, and
line input 2. Each source can be individu-
ally assigned to the left channel, right
channel, or both left and right. This allows
a wide variety of stereo and mono head-
phone mixes to be created.
The two audio signals associated with
the IFB input can be assigned to the
headphone output. Originating in produc-
tion trailers, control rooms, or remote
locations, these unbalanced sources
normally provide DC power and program-
with-interrupt audio on one channel and
program-only audio on the other.
For application flexibility, two line-level
audio sources can also be connected
to the Model 220. Possible signal sources
include off-air receivers, wireless IFB
systems, and audio consoles. The con-
nected signals can be from two indepen-
dent sources, or could be a stereo audio
feed such as would be associated with a
broadcast music event. Two trim poten-
tiometers, located on the bottom of the
unit, allow signals with wide nominal audio
levels to be cleanly interfaced.
Headphone Output
Two rotary controls are provided for user
adjustment of the headphone output
levels. For application flexibility, the actual
function of the two “pots” is configurable.
For traditional on-air sports applications
they can be selected to the dual level con-
trol mode, which provides independent
control of the left and right channel vol-
ume. For use with stereo cue signals,
or to support user preference, the level/
balance mode can be selected. In this
mode one control adjusts the overall level
of both the left and right channels, while
the other allows adjustment of the left/
right level balance. To help minimize the
chance of broadcast cues being missed,
both level control modes can be con-
figured so that a minimum headphone
output level is maintained. Alternately, the
headphone output can be set to fully
mute when the controls are at their mini-
mum position.
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.