Issue 93


Ableton Live 12
What’s in. What’s out. What to expect.


Full Bucket Music: The Qyooo

A free virtual synth plugin with an XY filter interface.


29 November 2023

German programmer and software engineer Björn Arlt began building VST plugins under the name Full Bucket Effects in 2010. Being a musician, and a synth enthusiast from a young age, he was drawn to analysing and building software synths. He now offers both synth emulations and effects as freeware through his website.

The Qyooo is a virtual polyphonic synthesizer which features three oscillators and a white noise generator that feeds a bank of three filters. Alternatively, the signal of an oscillator can be replaced by the ring-modulated version of itself with another oscillator (Osc. 1 + Osc. 2, Osc. 2 + Osc. 3, or Osc.3 +Osc. 1).

Each oscillator generates five different waveforms: Sawtooth, Pulse (including Pulse Width Modulation), Sine, Triangle, and Prime (a waveform containing only prime number fundamentals i.e. 1, 2, 3, 5, 7, 11, 13, 17,…). Finally, four LFOs and four envelopes are available for modulation purposes.

At the heart of the Qyooo is the Filter Bank, which consists of three individual filters. Each filter mode can be set to Lowpass, Lowpass-x (a distorted version that features in the Kern plugin), Bandpass, High-pass, All-pass, or Bypass. All filters have 4 poles except for the Lowpass-x which has 2 poles, and Bypass which has no pole at all. The filters can be arranged in eight different ways: Parallel 1, Parallel 2, Semi-Parallel 1, Semi-Parallel 2, Semi-Parallel 3, Semi-Parallel 4, Semi-Parallel 5, and Serial.

The parameters of the three filters (Cutoff, Resonance, Volume, and Panorama) are organised in four scenes: A, B, C, and D. Filter modulation is provided by morphing between these scenes. This means that you can continuously move from one setting for all filters (a scene) to a totally different one (another scene) in two dimensions.

In each direction (horizontal and vertical), three different modulation sources are available for Scene Morphing. Combined with the many filter modes and arrangements, this results in a huge variety of possibilities starting from simple frequency or resonance modulation, to panorama control and format morphing. To visualise the effect of the morphing, the Qyooo features a small monitor where a green ‘blip’ displays the current morph state of the voice that was last triggered. This ‘blip’ can also be dragged to manually morph between scenes.

  • Three zero-delay feedback filters with different modes and arrangements
  • Complex Scene Morphing section for filter modulation
  • Three band-limited oscillators including Ring modulation
  • Additional white noise generator
  • Four LFOs and envelopes
  • Up to 64 voices polyphony including portamento
  • Chorus effect
  • Supports MTS-ESP by ODDSound dynamic micro-tuning
  • Resizable user interface (not N version)
  • MIDI Learn – all parameters can be controlled by MIDI CC
  • 25 additional presets by Krezie Sounds
  • Plugin supports Windows and macOS (32 bit and 64 bit)

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Issue 93


Ableton Live 12
What’s in. What’s out. What to expect.