Serum is the synth everybody reaches for, and now Xfer Records has squeezed a pocket-sized version of it into something called Shrub. It is a stripped-down Serum that runs as a free VST3, in your browser, or as firmware on the little M-VAVE FM-1 hardware box. The name undersells it. This thing is a proper little beast.
Under the hood you get two wavetable oscillators, a sub oscillator and five noise colors, with 64 built-in wavetables plus your own tables and an additive mode. The filter alone has 76 types, which is more than most full-sized synths give you. Modulation is where it starts feeling like the real deal: three envelopes, four drawable LFOs, two chaos generators and a 16-slot matrix, plus a seven-slot effects rack borrowed from Serum 1. Voice Control, scales and the algorithmic arpeggiator come over from Serum 2, so it is not just a cut-down clone, it is a mix of both generations.
The honest bits: it plays four notes at a time and every note shares one stereo filter, so big chords will not sweep the way they do on the full Serum. Xfer also warns it is not especially light on CPU despite the small interface. And the VST3 skips the SEQ tab, so step sequencing still lives in the browser editor for now. But for industrial and dark electronic work, a free wavetable synth with 76 filter types and Serum 1 preset import is hard to argue with. I can see this living on a bass track or a nasty lead and nobody in the room knowing it came from a free beta.
Price: free while in beta. VST3 on macOS, Windows and Linux, plus a browser editor that plays it without installing anything.
Grab it here: https://shrub.audio/