Hansen Audio’s K-Whooms is a free virtual analog synthesizer available for Windows and Linux. It first appeared in 2024 and was updated in 2025, but we haven’t featured it on BPB until now.

I’ve been getting more requests to cover Linux-compatible software on BPB, and K-Whooms somehow flew under my radar. It was mentioned in our community section (thank you, Numanoid!), and after spending some time with it, I think it’s well worth sharing with a wider audience.

K-Whooms is a pretty solid subtractive synth that doesn’t try to reinvent the wheel. What it does is cover everything a good subtractive synth should cover and then some, all wrapped in a well-organized interface.

Actually, that interface is one of my favorite things about it.

Everything is laid out clearly, making K-Whooms a solid pick if you’re new to synthesis. If you’ve been wanting to learn how a modulation matrix works or try step sequencing inside a synth for the first time, this is a good place to start.

The synth features two multi-oscillators, each with up to nine phases that you can dial in steplessly. You can spread and detune the phases and widen the panorama for thicker sounds.

There’s also a noise generator with an adjustable characteristic ranging from blue through white to pink.

K-Whooms offers 12 filter types, including a ladder filter. The modulation matrix has eight assignable slots with target updates that can sync to the host tempo.

Modulation sources include an envelope and two LFOs, and you can also route Steinberg note expression parameters (volume, pan, pitch, and custom) on a per-note basis.

The modulation matrix is really well done and easy to use. It’s the part of K-Whooms I enjoyed the most.

Combined with the built-in step sequencer, simple distortion, and stereo delay effects, there’s plenty of synthesis firepower packed into this plugin.

Time and rate parameters can sync to host tempo, and the GUI scales from 100% to 200% in four steps.

K-Whooms is a VST3 plugin for Windows and Linux and is completely free.

Download: K-Whooms by Hansen Audio (FREE)

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Last Updated on March 13, 2026 by Tomislav Zlatic.