Ultramaster KR-106

The Ultramaster KR-106 is a free, open-source software synthesizer that faithfully recreates the classic Juno-106 sound. Built by a team with roots in 1990s Linux audio, it has been rebuilt for modern systems with a refined engine while keeping the familiar interface. It offers 60/106 mode, 6/8/10 voice polyphony, band-limited DCOs, an IR3109 VCF, and MN3009 BBD chorus for authentic analog character. The DAW-synced arpeggiator and LFO, 128 factory presets, oscilloscope, and component variance controls make it expressive and easy to tweak. MIDI Learn and SysEx support streamline integration. Ideal for hobby producers in FL Studio, Ableton, or Logic seeking warm, vintage synth tones for electronic, pop, and lo-fi tracks. The QWERTY keyboard enables quick auditioning. As a community-driven project, it invites users to help calibrate against real hardware, ensuring accuracy. Completely free with no donations, it’s a passion project giving back to the music community.