The Orban Model 464A Co-Operator™ Leveler/Compressor/HF Limiter is an integrated automatic gain control (AGC) device of the highest professional quality. The Co-Operator is a friendly, automatic “assistant operator” that smoothly and unobtrusively rides gain, controls high-frequency levels, and limits peaks. The Co-Operator achieves its outstandingly transparent audio performance through the use of finely-tuned control loops which eliminate the dynamic distortions that are the downfall of most conventional compressors and limiters, and through the use of a clean, class-A proprietary VCA to ensure negligible static distortion and noise. • A smooth leveler function provides transparent gain riding — without longterm distortion-producing overshoots. • A faster “compression” function can be switched in to provide additional transient overshoot protection for material with abrupt level changes or unusually high peak-to-average ratios. The compression function is available without leveling for applications that require safety limiting only. • Release time and release shape are adjustable to optimize processing for music or voice. • A defeatable “silence gate” prevents noise rash-up, holes, pumping, and breathing by inhibiting sudden gain increases once the signal level falls below a preset threshold (during pauses or low-level program material). • Six switchable HF limiter pre-emphasis/de-emphasis curves (25 to 150|i.s) allow the HF limiting to react optimally for the medium or device being protected and guard against excessive sibilance. • A defeatable clipper follows the HF limiter for absolute peak protection. • Either stereo-tracking or independent two-channel operation can be selected. • The least-used controls are concealed behind a security panel to avoid confusing non-technical operators, and to permit tamper-proof calibration. • Two LED bargraphs per channel simultaneously display gain reduction and peak output levels. • Output level meter can be calibrated to match the overload point of the device being drivea • Balanced, floating inputs and outputs are Electronic Measurements Inc. suppressed; the Co-Operator is compatible with the levels and impedances found in both professional and semi-professional applications. • 25dB gain reduction range is achieved with a low-distortion, class-A VCA. • Two channels packaged in a space-saving, rugged, all-metal, 1 %-inch chassis. • Hard-wired bypass switch is included.