As Kawai's second generation, the SX family adds polyphony, a sub oscillator, memory, portamento, larger keyboard, tape interface, and various modulation improvements. Multiple waveforms can be selected.
Architecture Class: Conventional (subtractive).
Ebay Description:
The Kawai SX-210 is a 61 key 8 voice synthesizer, featuring a single oscillator (with sub and saw/pulse/square/noise waveforms), a resonant low pass analog filter, a high pass filter, dual ADSR envelopes, an LFO (saw/triangle/square waveforms), portamento/glissando, 32 presets, tape interface, and chorus.