Processing and Control for Professional AV Installations
Legacy Hardware

422 Stereo AGC-Leveler

The 422 has been designed to give professional audio users unequaled performance, ease of use, and reliability. This manual will guide you through installation and operation of the 422 and provide valuable tips on how to interface with other equipment in your system. The 422 is a singular solution for controlling unpredictable stereo (or monaural) audio levels in a wide variety of audio systems. Application environments include broadcast, recording, tape duplication and installed foreground and background systems just to name a few. The 422 excels at subtly and unobtrusively bringing level divergent audio into a target window, resulting in greater intelligibility and informational perception. Unlike compressor/limiters, which are effective at reducing sounds that are too loud (pushing down from the top only), the 422 provides both downward compression and upward leveling by gently adding gain to low level signals until a target level is reached.

FAQ

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 too high. Turn this control further counter-clockwise.

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 as music or speech.

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

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.