Double Freak

Double Freak is a free two-oscillator synth by bjango, entered in the KVR Developer Challenge 2026. Unlike a keyboard synth, it’s an audio-following instrument: it tracks the pitch of incoming audio and layers sawtooth, square, and triangle oscillators over it to thicken the source. Feed it a vocal or a melodic line and it doubles the pitch with synth character.

The design bet

Its defining trait is deliberate unpredictability: the roundup notes the pitch tracking is intentionally erratic on polyphonic and atonal input, so on anything but a clean monophonic melody it becomes a texture/effect generator rather than a clean doubler. Analog-modeled distortion plus envelope-driven pitch-bend at note onset let you reshape both the texture and the shape of melodic lines. BPB rates it highly on vocals.

Available in AU and VST3 for macOS and Windows. It sits at the boundary between synth and effect — a pitch-tracked sound source driven by external audio — which makes it the roundup’s oddest entry against the keyboard-driven others. Source is a press roundup (T3, subjective).

Related

bjango · synthesizer · audio-effect-plugin · kvr-developer-challenge · identity-synth