: 422 Stereo AGC-Leveler

The units will not attempt leveling action on a sine wave or pink noise because they do not recognize a sine wave or pink noise as true audio. To test the units, you must use a real-world audio source, such…

You may have the RATIO control set too low. Try turning it up to around 4:1.

On the 421m, the AUTO RELEASE THRESHOLD may be set too high. Turn this control further counter-clockwise. Additionally, the EXPANDER THRESHOLD may be set too high. Turn this control further clockwise. On the 422, the DETECTOR THRESHOLD may be set…

Set the Limiter THRESHOLD control so that the LIMITER LED just flashes occasionally, on peaks in the music. If you need more leveling action, turn the RATIO control up to 4:1 or higher.