FlowFilter, Tesseract Echo, Lil’ Doc: Free Plugins of the Week
This week’s collection of free plugins brings you a filter with heaps of modulation, a deeply tweakable tape delay, and a slamming compressor. Check out FlowFilter, Tesseract Echo, and Lil’ Doc!
Free Plugins of the Week
Stagecraft Software FlowFilter: Creative Filter with Deep Modulation

FlowFilter by Stagecraft Software is the follow-up to the developer’s AutoFilter plugin released back in 2022. However, it’s been completely redesigned around a new stage-variable filter core. According to Stagecraft, this ensures a cleaner, more analog-style character that responds well to modulation.
FlowFilter includes a whole bunch of different filter modes, ranging from modeled analog filters to comb, formant, and tone filters to morphing filter modes that can take your sounds to new places. The plugin also features a capable built-in modulation engine with an LFO, an ADSR envelope, and a sequencer for rhythmic modulation. All the creative filtering you need – in a free plugin!
FlowFilter is available for macOS and Windows in VST3, AU, and AAX formats.
Trebless Tesseract Echo: Multi-Tap Tape Delay and Reverb

Tesseract Echo by Trebless is a free tape delay and reverb plugin with lots of extras, such as advanced modulation, a Karplus-Strong synthesis engine, and a built-in ducker.
At its core is a 4-head tape engine with independently adjustable level and pan per head, letting you create interesting tap rhythms. The delay section also features an analog-style drive stage in the feedback loop for some added grit. The delay time can be modulated in stereo, which produces anything from tape-style wow and flutter effects to audio-rate modulation mayhem.
In addition, Tesseract Echo includes a reverb based on a feedback delay network. There’s also a built-in sidechain compressor that can be used for ducking. And as if this wasn’t enough, you can even tune the delay time to incoming MIDI notes, turning the plugin into a Karplus-Strong synthesizer.
Tesseract Echo is available for macOS, Windows, and Linux in VST3, AU, LV2, and AAX formats.
Sketch Audio Lil’ Doc: Detroit-Style Slam Compressor

Sketch Audio has pulled the compressor from the Doctor Vibe plugin and made it available for free! Lil’ Doc uses the same compression algorithm as Doctor Vibe, which is inspired by the vinyl compression algorithm from an early 2000s sampler.
It’s pretty simple: Turn up the Slam knob to push your signal into oblivion. For good measure, they’ve thrown in some vinyl noise and crackle, converter drive, and four sample grade settings.
Lil’ Doc is available for macOS and Windows in VST3, AU, CLAP, and AAX formats. It also works on iOS as an AUv3 plugin.
You’ll find more free plugins like FlowFilter, Tesseract Echo, and Lil’ Doc in our archive!
