Sucrose

Name: Sucrose
Author: UnplugRed

by UnplugRed · Saturation · Harmonic and subharmonic generator

Not rated yet

Sucrose is a free harmonics plugin from UnplugRed and blepfx that creates harmonics and subharmonics with a Hilbert-transform phase-multiplication method.

It adds a subharmonic, 2nd and 3rd harmonics without changing dynamics, with less intermodulation than distortion; it is open source.

Best for: Drums, Vocals, Bass, Keys & Synths. Genres: all genres.

Keywords: sub bass, bass, open source, clean, electric guitar, free, kick, synths, low latency, vocals, simple, drums, live performance, mixing, playful, single-band, tracking, zero-latency.

What it does

Sucrose is a free harmonics plugin by UnplugRed and blepfx that adds 2nd and 3rd harmonics and a subharmonic without distorting the signal. Instead of waveshaping, it uses phase multiplication based on a Hilbert transform, so dynamics stay intact and intermodulation stays low.

Subharmonic: an octave-down component, inspired by guitar pedals, for bigger basses and kicks.
2nd and 3rd harmonics: separate controls for shaping guitars and synths so they cut through.
Band modes: Bedroom Producers Blog describes three modes with 1, 4 or 16 bands.
Clean output: no change to dynamics and little intermodulation, unlike typical distortion.
Zero latency: usable while tracking or playing live.
Interface and team: a stylised, playful interface by UnplugRed, with DSP by blepfx.

The current version is 1.0. It is free, open source under GPL3, and was a 2026 KVR Developer Challenge entry.

Source: UnplugRed product page

When to use it

Sucrose is the pick when you want added harmonics or sub weight without audible distortion. Compared with Decapitator or Saturation Knob, it doesn't drive the waveform, so it adds no compression or grit, just the chosen harmonics. Unlike RC-20 Retro Color or IVGI, it has no vintage colour or noise; it is a precise, clean tool. It is also free and open source.

Best for: subharmonic weight on bass and kick, and clean 2nd and 3rd harmonics on guitars, synths and vocals.
Genres: any, especially electronic and bass-heavy music.
Look elsewhere if: you want the grit and compression of real distortion; Decapitator or Saturation Knob fit better.
Tip: a KVR user suggests trying it instead of EQ on bass synths.

What producers say

Early users and press like it as a simple, effective free tool.

KVR users rate it 4.17 out of 5 from 6 reviews; one called it "a simple, great plugin" that does what it intends.
Bedroom Producers Blog said "I love the overall concept a lot" and found the subharmonic great for making basses and kicks feel bigger.

Where to buy

UnplugRed: Free

Tutorials and reviews

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