Fourm is a compact analog synthesizer that invites you to play, shape, and perform with unprecedented expression. With its legendary Sequential tone, hands-on modulation, and uniquely responsive Tactive keybed, Fourm is a creative partner helping to bring your musical ideas to life.

Fourm delivers four genuine voices of Sequential analog sound, built on the legendary Prophet-5 voice architecture—right down to its characteristic envelope response curves. With dual oscillators offering simultaneous wave selection and a classic 4-pole low-pass filter with bass compensation, Fourm captures the warmth and punch that shaped a generation—and takes it to the next level.

Fourm’s analog voice path is built around a modern oscillator chip inspired by the design used in the original Prophet-5 Rev 2. It delivers the same rich, musical tone as its vintage predecessor, now enhanced by the benefits of contemporary engineering — improved stability, reliability, and consistency. It’s the perfect foundation for Fourm’s 100% analog sound.

Fourm’s analog 4-pole lowpass filter chip is based on a classic design known for its rich, organic tone and musical resonance. The modern implementation faithfully preserves that sonic character while adding bass compensation. Now you can crank the resonance without sacrificing low-end power — keeping your sound full, bold, and unmistakably analog.

Tucked into the arpeggiator section, Fourm’s polyphonic step sequencer is a creative powerhouse. Yes, it can play back musical phrases — but it can also be used as a modulation source, perfect for triggering rhythmic filter patterns and more. With support for chords, ties, rests, Acid-style per-step glide, and deep modulation routing, the sequencer transforms Fourm into a dynamic, hands-on composition tool.