When Kawai released the SX-210 in 1983, they were aiming directly at the heart of the polysynth market dominated by Roland and Korg, but this machine took a distinctly different approach to voice architecture that made it stand out among its competitors. It's a synth that rewards deep exploration and has quietly developed a devoted following among players who appreciate its particular flavor of analog warmth and its unusual flexibility.
The SX-210 is an 8-voice polyphonic synthesizer built around a single digitally controlled oscillator per voice, with waveforms including sawtooth, square with pulse width modulation, a sub-oscillator, and noise. The signal path is entirely analog, running through an SSM-2044 based low-pass filter paired with a separate high-pass filter, each with its own dedicated ADSR envelope. A single LFO with three waveforms and adjustable delay can modulate the oscillator, filter, and amplifier simultaneously. The 61-key velocity-sensitive keyboard connects to a control interface built around a single encoder dial and parameter buttons, a design choice that feels sparse compared to its era's competitors but gives the SX-210 a clean, focused aesthetic. The wooden side panels and solid construction reflect early 80s build quality, and the synth weighs just over 12 kilograms, making it reasonably portable for its class.
What truly sets the SX-210 apart is its voice architecture flexibility. Beyond standard 8-voice polyphony, you can switch to a 4-voice mode that stacks two oscillators per voice for dramatically thicker tones, or engage the unison lead mode that combines all eight oscillators into a single monophonic voice for massive, detuned leads. The chord memory function lets you stack up to seven different notes into a single voice, creating instant harmonic textures. Additional performance controls include portamento, glissando in semitone steps, pitch bend with adjustable range, and key hold for sustaining notes. The built-in ensemble effect provides stereo widening, and 32 patch memories let you store your creations, with tape interface support for archival and sharing.
