Korg Monotron

Introduced in 2010, this pocket-sized analog synth marked Korg's return to pure analog circuits after nearly three decades, packing the legendary MS-10 and MS-20 filter into a device smaller than a cassette tape.

At its heart lies a single voltage-controlled oscillator producing a sawtooth waveform, shaped by a 12dB/octave low-pass filter with cutoff and peak/resonance controls for everything from warm bass to howling leads capable of self-oscillation. A versatile LFO with rate and intensity knobs—complete with an LED indicator—modulates either pitch or filter cutoff, while a ribbon controller handles expressive monophonic playing across a full pitch range. Five main knobs keep operation dead simple and intuitive, with aux input for filtering external audio, a built-in speaker, headphone out, and power from two AAA batteries; it measures just 120 x 72 x 28 mm and weighs 95g.

Players love its raw, hands-on joy and that iconic filter's aggressive character, which shines in live tweaking or as a creative effect processor—though some note the ribbon lacks scale markings and it's strictly monophonic. Even discontinued, it remains a gateway to analog experimentation for beginners and pros alike.