Studio Technologies 210 2012 - Manual (Page 34)

Issue 5, September 2012 Model 210 User Guide
Page 34 Studio Technologies, Inc.
Compressor Circuit
In this section some general information
about the Model 210’s compressor
circuit will be provided. As previously
discussed, the output of the microphone
preamplifier circuit is connected to a
studio-quality compressor circuit. The out-
put of the compressor is used by the talk-
back output and, if configured, the main
output. (In most cases the main output
will utilize the signal coming directly out
of the microphone preamplifier.) The gain
element in the compressor circuit is a
laser-trimmed voltage-controlled-
amplifier integrated circuit. It provides
accurate, low-noise, low-distortion per-
formance. The threshold of the compres-
sor circuit is 2 dB above the Model 210’s
nominal internal operating level of –2 dBu.
A 5:1 compression ratio is implemented
and, like the threshold level, is not field
adjustable. The threshold and ratio set-
tings were selected so that excellent
talkback audio would be provided. By
controlling the dynamic range, intelligibility
can be improved and overloading of con-
nected devices can be avoided. An LED
indicator lights whenever the compres-
sor’s threshold has been reached and the
circuit is actively controlling the dynamic
range. This LED is provided as an aid
when setting the gain of the microphone
preamplifier.