The blooo

Name: The blooo
Author: Full Bucket Music

by Full Bucket Music · Synth · Subtractive synth

Not rated yet

The blooo is a free subtractive synthesizer with two band-limited oscillators (five shapeable waveforms, ring mod and sync) and two multimode four-pole filters.

It has three ADSR envelopes, three tempo-synced LFOs and up to 64 voices with unison; it is free.

Best for: Keys & Synths, Sound Design. Genres: Electronic & EDM, Pop, Hip-Hop & Trap.

Keywords: subtractive, free, polyphonic, tempo-synced, classic, modulation matrix, analog, basses, CPU-light, FM, hardware emulation, leads, monophonic, pads, resizable UI, sound design.

What it does

The blooo is Full Bucket Music's free two-oscillator subtractive synth. It follows a "classic subtractive synthesis architecture" and is written in native C++ to run well "even on 'lighter' systems".

Oscillators: two band-limited oscillators with sawtooth, pulse, sawpulse, sine and triangle. Shape (pulse width on the pulse wave) can be modulated, Pitch covers ±24 semitones, and two FM inputs reach up to ±5 octaves.
Sync and analog touches: Soft or Hard sync of oscillator 2 to oscillator 1, and a Free switch that emulates free-running analog oscillators at note start.
Ring mod and noise: a ring modulator (oscillator 1 times oscillator 2) and white noise, each with its own level in both filter input mixers.
Two filters: four-pole zero-delay-feedback filters with Lowpass, Highpass, Bandpass, Allpass and Phaser modes. Each has its own input mixer, and filter 2 can take filter 1's output, so they run in series or in parallel.
Filter controls: cutoff with three modulation inputs, resonance up to self-oscillation, pan with modulation, two amplitude modulation inputs and volume per filter.
Envelopes and LFOs: three ADSR envelopes with exponential slopes and a Single trigger mode (envelope 1 drives the amp), and three LFOs (Sine, Square, Saw Up, Saw Dn, S/H, 3-Step) from 0 to 100 Hz or synced to the host.
Modulation sources: envelopes, LFOs, velocity, note value, pitch bend, mod wheel, and channel and poly aftertouch.
Voices and output: 1 to 64 voices, a Unison mode that stacks up to 8 detuned voices, portamento up to 5 seconds, pitch bend up to ±24 semitones and a tanh Clip stage on the output.

It also offers MIDI Learn, MTS-ESP micro-tuning and a resizable UI. The current version is 2.3.5 (15 March 2025), and an English manual is available. It is a free download; the developer accepts donations.

Source: Full Bucket Music product page

When to use it

The blooo is the better pick when you want a free, light, classic two-oscillator synth with real depth under the hood. Compared with Sylenth1 and Hive 2, it has no built-in effects beyond the output clipper and a much smaller preset bank, but its two routable filters with Phaser and Allpass modes, sync and aftertouch modulation cover the same basic subtractive ground at no cost. Against Vital it is simpler and lighter, with no wavetables or effects rack. Next to Full Bucket's own The qyooo, it drops the third oscillator and Scene Morphing in exchange for a smaller, quicker panel.

Best for: everyday subtractive basses, leads, sync sounds and pads at low CPU cost.
Genres: electronic, pop and hip-hop.
Look elsewhere if: you want built-in effects and big preset banks; Sylenth1 or Hive 2 are more complete, and Vital is free with wavetables and effects.

Where to buy

Full Bucket Music: Free

Tutorials and reviews

Similar plugins

Twin 3 by FabFilter · Subtractive synth · $129
TyrellN6 by u-he · Free analog-style synth · Free
Kern by Full Bucket Music · Performance synth · Free
The qyooo by Full Bucket Music · Complex modulation synth · Free
LION by Unfiltered Audio · Dual-oscillator synth · $100
Reaktor Spark by Native Instruments · Subtractive synth · $49
Element 2.0 Virtual Analog Synth by Waves · Virtual analog synth · $34.99
Albino-3 Legend by Rob Papen · Multi-layer subtractive synth · $93.08
MPowerSynth by MeldaProduction · Subtractive synth with modular effects · $99

All synths