421 AGC Leveler

The Symetrix 421 is a wide-range AGC-Leveler, a peak limiter, and a
downward expander. The 421 reduces the dynamic range of its input
signal by the amount of its ratio setting. That is, if the ratio
setting is 2:1, then 40 dB of input range turns into 20 dB at the
output. A fast peak limiter puts an...