This two-channel unit with all discrete-transistor audio path features an extraordinary range of control allowing simulation of various fundamental automatic gain-control characteristics. The 8900 is the result of 22 years of research, prototyping, limited manufacturing, and features two RMS and one peak detector per channel, multiple variable crest factor controls and selectable soft/hard knee adjustments. The unit combines highly accurate log converters, true RMS detectors (which provide control of signal energy not just level), and other modern analog processing techniques in a stable "feed-forward" topology. The model 8900 also has side chain input and fits into a 2U x 19" space.