When Bob Moog himself co-designed a synthesizer in 1983, you'd think it would have become legendary, but the Crumar Spirit remained one of the era's best-kept secrets—fewer than 100 were built originally, making it a rare gem that deserves far more recognition than it ever got.
The Spirit is a two-oscillator analog monosynth built around premium CEM integrated circuits, the same chips found in the Rhodes Chroma and Memorymoog. Each oscillator generates sawtooth, triangle, and square waves with sync capability, feeding into a genuinely impressive filter section that offers low-pass, high-pass, and band-pass modes with switchable 12dB or 24dB slopes. The signal path splits into two independent chains—one routing through the main filters and envelope, another controlled by the Shaper-Y section with its own ring modulator and noise generator. You get two ADSR envelopes, two LFOs called Mod-X and Shaper-Y, and an arpeggiator with three distinct patterns including a "Leap" mode that jumps across multiple octaves for intricate sequences. The control layout is hands-on and inviting: 24 knobs, 10 switches, 15 sliders, plus three performance wheels for real-time modulation of pitch, Mod-X, and Shaper-Y depth.
The original hardware has been largely appreciated by those who've encountered it for its exceptional filter character, particularly the formant capabilities, and its unusually flexible modulation architecture that lets you route modulation sources to nearly anywhere in the signal chain. The 37-note keyboard lacks velocity and aftertouch, which was typical for 1983 but does limit expressive possibilities compared to contemporary competitors. The original units also came with a MIDI port hole that was never actually functional—a quirk of its time.
Crumar has returned to production with a 2023 reissue that maintains the original circuitry and aesthetic while addressing obsolescence issues through careful component substitution and adding genuine MIDI IN connectivity. The modern version uses through-hole construction like the original and includes CV/Gate connectivity for modular integration.
