A compact subtractive synth: one oscillator into a resonant low-pass filter into an amplitude envelope. It is the classic signal path with nothing bolted on, small enough to learn in an afternoon and good for basses, plucks, leads and simple pads.
Controls
- Wave picks the oscillator: sine, saw, square or triangle. Saw is the brightest and the usual starting point. A sine has no harmonics for the filter to remove, so the filter barely changes it.
- Octave and Detune set the pitch: whole octaves up or down by two, and a fine offset of up to a semitone either way.
- Cutoff is the main tone control: where the low-pass filter starts removing brightness. The mod wheel moves it by default.
- Resonance adds a peak at the cutoff, from smooth to sharp and vocal.
- Env Amt lets the envelope move the cutoff up or down with each note, for plucks that open and close.
- Attack, Decay, Sustain and Release shape each note's volume. You can also drag the envelope curve directly.
- Gain sets the output level. CC 7, the usual volume controller, moves it by default.
Voices and glide
OSC Mini starts monophonic, one note at a time. The voice settings switch it to eight-voice polyphony or to Mono Legato for connected lines, choose which held note wins in mono (the last, lowest or highest), and add portamento: a glide between notes of up to two seconds, either always or only when notes overlap.
Getting started
Play OSC Mini from a keyboard or a MIDI clip. Start with the saw wave, pull Cutoff down and raise Resonance a little for a bass. Shorten Decay with Sustain at zero and add some Env Amt for a pluck, or slow the Attack and Release for a pad in polyphonic mode.
In hosts that support patching, OSC Mini also appears as a Eurorack-style panel with a MIDI input and an audio output jack.
