Cardinal vs Repro

Cardinal is a free, open-source modular synthesizer based on VCV Rack, available as a standalone app and as a plugin. It bundles 1,382 modules from 84 authors or brands, but does not load external modules or connect to the official Rack library or store; modules cannot be added to an existing build. Cardinal runs on Linux, macOS, Windows, and the web. Its plugin formats are AudioUnit, CLAP, LV2, VST2, and VST3, with Main, Synth, and FX variants that all support MIDI input and output. Main provides eight audio inputs and outputs and ten CV inputs and outputs, but is unavailable in AU and VST2 and is not yet available in CLAP. Mini has a smaller hand-picked module selection, two audio ports, and five CV ports, and is available only as LV2 or standalone. OSC remote control works in standalone use, not in the plugin. The project describes Cardinal as stable, while noting CLAP support is still in progress and VST3 hosting inside Carla or Ildaeil is experimental. It is licensed under GPLv3+.

Repro is a synthesizer plug-in containing Repro-1 and Repro-5 in one product and installer. Repro-1 models a monophonic analogue keyboard and can step-record two patterns of up to 32 notes each. Its five rearrangeable effects include a wavefolder, delay, EQ/resonator, reverb and sonic conditioner. Repro-5 supports up to eight-voice polyphony or unison, with optional glide, and includes more than 950 factory presets and a polyphonic distortion unit with four modes, including a bit crusher. The product runs on Linux, macOS and Windows, but is not standalone and requires host software; it supports nearly all DAWs. The listed plug-in formats include CLAP, AUv2, VST3 and AAX on macOS, and VST3, CLAP and AAX on Windows. Repro is NKS-ready and compatible with Maschine and Komplete Kontrol hardware. The listed Repro plan costs €149 as a one-time purchase, and a free trial is available; its demo emits a crackling sound. Linux builds are beta and receive less support than macOS and Windows versions.