Studio Technologies 220 2008 - Manual (Page 40)

Issue 4, October 2008 Model 220 User Guide
Page 40 Studio Technologies, Inc.
case it may possibly reduce the micro-
phone signal level by less than one dB.
Two 150 ohm resistors are electrically
connected in series between the micro-
phone input connector and the direct
microphone output connector. These
resistors provide isolation, allowing the
direct microphone output to be muted
while still maintaining microphone audio
on the Model 220’s preamplifier input.
This audio is necessary so that the talk-
back functions can continue to operate.
The series resistors will have minimal
impact, simply raising the microphone’s
apparent source impedance as “seen”
by the external preamplifier.