Twenty-two years of progressive research into loudness perception resulted in a limiter/compressor unlike any other. The 8900 Dynamic Range Controller was intrinsically developed to react to loudness (rather than voltage) like our ears do. The 8900’s psycho-acoustic approach uses multiple true-RMS detectors, remarkably accurate log converters, and fast peak detectors to respond intelligently to real signal energy, not just electrical level. This innovative design employs unique controls like Crest Factor, Timing, and Release Hysteresis to precisely control the dynamic features of musical performances; one would ordinarily change out the entire unit to gain this flexibility. Familiar features such as Stereo Link, Soft/Hard Knee, Ratio, Output Level, as well as the comprehensive 40-segment tricolor Gain/Loss metering have been carefully optimized for flexible, creative control over a wide dynamic range with a noticeable lack of audible artifacts. A Side Chain Input permits external frequency shaping to be introduced into the detection circuitry. The entire audio path is all-discrete, including the custom-built VCA, for unsurpassed transparency and low-level resolution. The 8900 is a 2U, two-channel unit which requires one 9015 power supply.

 

SPECIFICATIONS

 

INPUT

20 kOhm balanced bridging; Pin 2 hot

57 dB common mode rejection at 20kHz

+27.4 dBv maximum before clipping

Individually channel swichable on back panel for +4 or -10

 

THROUGHPUT

±0.1 dB, 16 Hz to 68 kHz response (controls at zero)

0.01% Harmonic distortion at any frequency 20 Hz - 20 kHz1, no gain reduction

0.009% SMPTE Intermodulation distortion2

30 v/usec discrete low noise, high performance amplifiers

no electrolytic interstage or output coupling capacitors

noise -96.5 dBv bypassed, -74 dB absolute worst case (control position dependent)

rolloff: 3 dB down at 260 kHz

FORM FACTOR - 2 CHANNELS, Each with Separate Peak and Dual RMS Detectors

Discrete VCA; Discrete Audio Chain

Front Panel Sidechain; Stereo and multiple unit control link

40 Segment Tricolor meter; Meter range -20 to +20, true gain through unit

4 segment instantaneous ratio meter (approximate indication of soft knee actuation)

Peak, FastRMS and SlowRMS indicators

 

OUTPUT

+27.4 dBv clipping; unbalanced; Pin 2 Hot

3 mv output offset, stabilized by D.C. servo correction

 

OTHER

external power supply: ±28 VDC & ±18 VDC

ground and chassis straps at rear

19" x 3 1/2" rack case, black anodized aluminium, silver legend, 8 1/2" deep

weight: 7 lbs.