With 945 waveforms per oscillator and an 8-voice polyphonic engine, this DIY synthesizer delivers an extraordinary range of sonic possibilities in a compact desktop format. Built around the Teensy 4.1 processor, the Jeannie combines classic synthesis architecture with modern digital capabilities, featuring dual oscillators with sync and FM modulation, multimode filters with both 12dB state variable and 24dB ladder configurations, and a waveshaper uniquely positioned after the filter for distinctive timbral character.
The sound design toolkit extends far beyond basics with two ADSR envelopes, three LFOs, ring modulation, and logical operators like XOR and OR for complex modulation routing. An 8-fold unison mode stacks up to 16 oscillators within a single voice, while the 14-effect digital processor—running at adjustable clock rates from 10 to 60 kHz—covers everything from pristine chorus and reverb to aggressive distortion and pitch shifting. A 16-step sequencer and 2048 program storage via microSD card round out the creative arsenal.
As an open-source project, the Jeannie invites hands-on builders into its architecture while remaining accessible through active firmware development. Recent updates introduced 21 new oscillator models sourced from Mutable Instruments' Braids and Shruti, including vowel synthesis and 8-bit textures alongside traditional waveforms. The combination of deep modulation capabilities, extensive effects processing, and constantly evolving software makes this a platform for serious sound exploration rather than a static instrument.
