Korg - KP-30 Sigma - - Keyboard-synthesizer - Japan - 1979

Korg Sigma KP-30 is a rare, vintage monophonic analog synthesizer released by Korg in 1979. It was specifically designed for live performance and organ players, featuring a unique bi-timbric architecture and a highly expressive layout.

It features two separate synthesizer sections—"Synthe" (an analog section with variable waveforms like square, pulse, and sawtooth) and "Instrument" (an 11-preset section mimicking traditional instruments like flute, strings, and trumpet). These two engines can be layered together using a unique set of selector tabs.

It comes equipped with two multi-directional joysticks. One manages pitch bend, vibrato, and noise depth, while the other provides dynamic control over the high-pass and low-pass filters (similar to the famous Korg MS-20).

Features a 37-key keyboard with aftertouch sensitivity, a ring modulator (cross-modulation), a sample-and-hold generator, and a unique quarter-tone tuning capability.