Idle Foundry CA-72 is a free, open-source synthesizer that models the Minimoog Model D of about 1972 to 1973 with the CA3046 oscillator board. The circuit was transcribed from the instrument's service documents into SPICE netlists, simulated in ngspice, and the real-time models were derived and checked against that reference, factory calibration included. It is monophonic like the original, or up to ten full voices in POLY mode, and it adds ENTROPY per-voice analog variation, SPREAD stereo placement and a built-in FEEDBACK overdrive.
Verified 5 October 2026: free and open source under GPL version 3 or later, version 0.1.0 first release. VST3 and CLAP for macOS 11 or later (Apple Silicon or Intel), Windows 10 or 11 64-bit, and 64-bit Linux. 24 factory presets. No AU or AAX in this release. We have not scored it.
For the full breakdown, see the CA-72 first look.