Ultramaster KR-106 is a free, open-source Juno-106 emulation available for macOS, Windows and Linux — download the KR-106 from the project page with source code included. The KR-106 recreates the classic 6-voice Juno-106 architecture and ships as a modern cross-platform synth build you can use right away.
What it is and how to get it
Ultramaster KR-106 is an open-source Roland Juno-106-style synthesizer emulation developed by Ultramaster. The release includes compiled builds and source code; grab the download directly from Ultramaster's project/download page (no payment required). There’s no reported time limit, but check the project page for the latest builds and licensing details.
Key features
- 6-voice polyphony with per-voice single three-wave DCO and PWM
- VCF (filter), VCA and ADSR envelope per voice
- Shared LFO, high-pass filter (HPF), chorus and arpeggiator
- Mono, Poly I and Poly II keyboard modes with portamento
- Two calibration modes for distinct tonal character
- Open-source project files and source code included
Specs & system requirements
- Platforms: macOS, Windows, Linux
- Voice architecture: 6-voice, single DCO per voice
- Common controls: filter cutoff/resonance, ADSR, LFO, PWM, chorus, arpeggio
- CPU/RAM: typical modern desktop/laptop suffices; more CPU for heavy polyphony and effects
- Licensing: released as open-source — check the developer project page for the exact license and commercial/royalty-free terms
Two calibration modes
Ultramaster KR-106 offers two calibration modes that change the voicing: a firmware/schematic-based