Casio CZ-230S

Back in 1986, this synth pioneered full MIDI in/out/thru on a consumer keyboard, blending phase distortion tones with a built-in drum machine pulled straight from the Casio RZ-1—perfect for jamming ideas without extra gear.

It packs 8-voice polyphony from dual DCOs per voice, driving Casio's signature phase distortion synthesis for metallic, evolving sounds via dedicated 8-stage envelopes on DCW, DCA, and pitch. The 49 full-size mini keys span four octaves with velocity sensitivity, a pitch bend wheel, portamento, and solo/monophonic modes, though it skips onboard vibrato or sustain buttons. You'll find 100 presets (99 fixed, 4 editable via computer over MIDI), a versatile sequencer in real-time or step modes, 12 programmable drum sounds, and a chorus effect, all outputting through a mono jack or built-in speaker. Battery-powered portability and multitimbral 4-part capability make it a quirky workstation hybrid.

Vintage players dig its raw PD character—crisp brass, glassy bells, and unique drums that stand out in mixes—but note the limited editing and auto-off after MIDI inactivity as classic quirks from the era.