GML 8900 Dynamic Range Controller w/ PSU #D-0315 (Used)

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 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.

FEATURES:

• Distortion reduction in the signal level determination processor.
• Improved smoothness of the “soft knee” transition generator.
• Increased transparency and low-level performance of the VCA circuitry
• Fully exploits modern analog processing elements, and surface-mount construction to offer unprecedented accuracy, reliability, and calibration stability

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 volts & ±18 V DC
• Separate ground and chassis connections at rear
• 19” x 3 1/2” rack case, black anodized aluminum, silver legend, 8 1/2” deep
• Weight: 7 lbs.