Greenoak Crystal v2.5.5 (MacOS/Windows) [FREE][x86,x64,vsti,au]

Crystal is a semi-modular software synthesizer featuring both subtractive synthesis and frequency modulation (FM) synthesis. It offers abundant modulation control with over 90 parameters which may be modulated, multi-stage envelopes with graphical editors, extensive tempo sync of envelopes/lforates/delay times, built-in effects for chorus/flanging/comb filtering/echoes, and a band splitter for effects processing by frequency band. Not only that, Crystal has wave sequencing, granular synthesis, program morphing, MIDI learn, and imports soundfonts. The musical applications for Crystal are literally boundless.

Crystal is a plugin, which means it runs within a host, such as Cubase, Orion, Logic, Fruity Loops, etc.

now also in 64 Bit

Homepage writes that it is updated for BigSur, so no M1 support of course. It looks like there is AU too. Windows has VST64bit. That synth is a kind of kiss from the past. Included are some soundsets and factory presets, which add some size to the download. So enjoy!