Studio Technologies 220 2008 - Manual (Page 6)

Issue 4, October 2008 Model 220 User Guide
Page 6 Studio Technologies, Inc.
System Features
Microphone Input
A high-performance microphone preampli-
fier circuit provides low-noise/low-distortion
amplification over a 20 to 60 dB gain range.
The gain is adjustable in 10 dB steps. The
input is compatible with balanced dynamic
and condenser microphones. The micro-
phone power source is 48 volts nominal
and meets the worldwide P48 phantom
power standard. An LED indicator serves
as an aid for optimizing the setting of the
preamplifier’s gain. The output of the mi-
crophone preamplifier is used by the main
output as well as being routed to the com-
pressor circuit that supports the talkback
functions.
Main Output
The Model 220 provides a main output that
is designed to serve as the on-air, stadium
announcement, or other primary audio
feed. Nominally –2 dBu, it is designed as
a fully professional interface with high
output capability, low distortion, and low
noise. It features a high-performance out-
put transformer expressly designed for
professional audio applications.
Talkback Outputs
The two talkback outputs are intended
to provide production trucks, control
rooms, or support personnel with talent-
originated cue signals. These outputs are
transformer-coupled with +4 dBu nomi-
nal signal levels. They contain resistors in
series with their output connector, allowing
the talkback outputs from multiple units
to be directly “summed.”
For special applications the Model 220
provides two alternate system modes that
impact talkback output 2. One mode pro-
vides a “hot mic” output, providing a line-
level version of whatever signal is present
on the connected microphone; no muting
of the output ever takes place.
A second system mode makes talkback
output 2 serve as a “mult” of the main out-
put; whatever signal is present on the main
output will be present on talkback output
2. With this system mode the major differ-
ence between the two outputs (main and
talkback 2) is that the compressor circuit
impacts the dynamic range of talkback
output 2.
For non-on-air applications, a special
Model 220 feature can be enabled, placing
the unit in a “production” mode. This allows
Figure 2. Model 220 back panel