Marantz EQ-20

Name: Marantz EQ-20
Brand: Marantz

The Marantz EQ-20 is a 10-band stereo graphic equalizer from the upscale ESOTEC separates line. It was sold from 1982 to 1984 (though some sources place production from 1980 to 1982) at around 300 DM (¥49,800 in Japan). Marantz first released it in Japan as a pair of separate left/right channel units for the ESOTEC system. The international version put both channels in a single chassis.

The unit has ten ISO-standard center frequencies per channel (63 Hz through 16 kHz). Boost/cut is ±12 dB (some sources specify ±10 dB), set with Marantz's own slide potentiometers. The signal path uses dual FET switches. There's an LED level meter, plus FLAT, CUT, and PEAK indicator lights. You can connect two tape decks, with cross-dubbing and tape record/playback/monitor switching. Commonly cited specs are THD of 0.005%, a signal-to-noise ratio of 110 dB, and input sensitivity of 0.1V. High slew-rate op-amps are credited with the wide 5 Hz - 100 kHz frequency range.

Dimensions are approximately 420 × 79.5 × 230 mm (other sources cite 420 × 79 × 225 mm). Weight is around 3.2 kg (other sources cite 3.0 kg). AC 120V/220V/240V versions were available. It was designed as a companion to the ESOTEC SC-20 preamp, MA-20 monoblock amplifiers, and ST-20 tuner.