Korg - RHYTHM 55B - Drum machine - Japan - 1981

The Korg Rhythm 55B (also known as the KR-55B) is a vintage analog drum machine released around 1982. It is a "black-chassis" update to the original 1979 KR-55, primarily distinguished by having double the rhythm patterns—96 presets compared to the original 48.
Sound and Instruments
The unit features 12 analog-synthesized drum sounds that are widely praised by reviewers for being "crisp," "punchy," and "meaty".
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Instrument List: Bass Drum, Snare Drum, Hi-Hat 1, Hi-Hat 2, Cymbal, Rim Shot, Low Conga, High Conga, Claves, Tom 1, Tom 2, and Cowbell.
Mixer Section: It includes a built-in six-channel mixer with individual sliders to adjust volume levels for specific sound groups.
Sound Characteristics: Reviewers on Equipboard note that it has a low noise floor and high-quality analog sound that often cuts through mixes better than some contemporary Roland models.
Rhythms and Sequencing
As a preset drum machine, it is not fully programmable but offers significant flexibility through variations and manual controls.
Pattern Variations: The 96 patterns are organized into groups with multiple variations (A, B, C) and related patterns that can be switched during a performance.
Fill-ins and Intros: It features manual "Intro" and "Fill-in" buttons, which can also be triggered via an external footswitch.
Swing Control: A "swing" or "shuffle" setting allows you to adjust the groove of all preset rhythms.
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Connectivity and Technical Specs
Outputs: It typically features mono High and Low signal outputs. Standard units lack individual outputs for each drum sound, though many vintage units found today have been modified to include them.
Sync (Trigger Out): A dedicated Trig Out (+5V) allows the machine to sync with external analog synthesizers or sequencers. A selector switch lets users choose the trigger timing (e.g., 1/4, 1/8, or 1/16 notes).
Footswitch Support: Dual footswitch inputs are available for remote Start/Stop and Intro/Fill-in functions, traditionally using the Korg S-2 footswitch.
Physical Build: It is known for its rugged, compact design, weighing approximately 2 kg.
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Historical Significance
The Korg KR-55B was famously used by pioneering electronic artists such as Depeche Mode, Jean-michel Jarre
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The Korg Rhythm 55B is a compact analog drum machine that weighs approximately 2 kg (4.4 lbs).
Vintage Digital
Vintage Digital
Physical Specifications
The unit's weight and size were considered relatively portable for studio equipment during its release in the early 1980s.
Weight: According to Vintage Digital, the machine weighs 2 kg.
Dimensions: The dimensions are listed as approximately 400 mm x 250 mm x 150 mm (roughly 15.7" x 9.8" x 5.9").
Build Quality: It features a rugged, predominantly metal chassis, which contributes to its weight despite its small footprint.