The state-variable filter has a Cutoff and a Resonance (Q). Type chooses low-pass, band-pass, high-pass, notch or all-pass, or Morph, which moves continuously from low-pass through band-pass to high-pass. Slope chooses one stage (12 dB per octave) or two cascaded stages (24 dB per octave). Higher resonance emphasizes frequencies around the cutoff, up to a ringing peak. Cutoff is capped at 0.45 times the sample rate.
Use it for filter sweeps, wah-style effects and subtractive tone shaping. Select Low-pass for a roll-off, High-pass to remove low frequencies, Band-pass to isolate a band, Notch to cut one, or All-pass to change phase. New filters start in Low-pass mode.
The graph shows the response for the selected type and slope. Drag across it to set Cutoff and vertically to set Resonance; the wheel adjusts resonance too. Hover or focus the graph while playing to see the real-time output spectrum (RTA) behind the response. Patch, Properties and Frame faces use the same editor.
Continuous low-pass, band-pass and high-pass morph. Shown when type is 0.
type
Type
0 to 5
1
linear
Selects the implemented algorithm. Choices are discrete and are not LFO targets. Choices: 0 Morph, 1 Low-pass, 2 Band-pass, 3 High-pass, 4 Notch, 5 All-pass.
slope
Slope
0 to 1
0
linear
One or two cascaded state-variable stages; notch/all-pass retain their response semantics. Choices: 0 12 dB/oct, 1 24 dB/oct.
compensation
Resonance compensation
0 to 1
0
linear
Reduces resonant gain as Q increases. Shown when type is 0 or 1 or 3.
Each help patch is an ordinary Toy that teaches one idea. The diagram shows the Patch; the preview shows its Frame. Open it in TuneToys to play and edit it.
1. Sweep a resonant filter
beginner Teaches: cutoff, resonance, type
A saw wave through a resonant filter with a mode choice.
Oscillator
MIDI1 lane
Audio2ch
Fundamental pitch, capped below Nyquist; detune uses cents. Range: 20–20000 Hz. Default: 220 Hz. Logarithmic scale. Units: Hz.
Hz
Output gain. Range: 0–0.5 ×. Default: 0.12 ×. Linear scale. Units: linear gain.
×
Selects the implemented algorithm. Choices are discrete and are not LFO targets. Range: 0–7. Default: 0. Linear scale. Units: unitless.
Cycle offset; Gate rising edges restart phase from this position. Range: 0–1 cycles. Default: 0 cycles. Linear scale. Units: cycles.
cycles
Pitch offset in cents. Range: -1200–1200 cents. Default: 0 cents. Linear scale. Units: cents.
cents
On or off. A rising edge retriggers; held on runs the oscillator or envelope. A control cable switches it at 0.5. Range: 0–1. Default: 1. Linear scale. Units: unitless.
Semitones a full pitch bend on the MIDI input moves the note, up or down. Range: 0–48 st. Default: 2 st. Linear scale. Units: st.
st
Time constant of the slide from one MIDI note's pitch to the next; 0 jumps. Range: 0–2000 ms. Default: 0 ms. Linear scale. Units: ms.
ms
Filter
Audio2ch
Audio2ch
Filter cutoff, capped at 0.45 times sample rate. Range: 20–20000 Hz. Default: 800 Hz. Logarithmic scale. Units: Hz.
Move continuously from low-pass through band-pass to high-pass.
Oscillator
MIDI1 lane
Audio2ch
Fundamental pitch, capped below Nyquist; detune uses cents. Range: 20–20000 Hz. Default: 220 Hz. Logarithmic scale. Units: Hz.
Hz
Output gain. Range: 0–0.5 ×. Default: 0.12 ×. Linear scale. Units: linear gain.
×
Selects the implemented algorithm. Choices are discrete and are not LFO targets. Range: 0–7. Default: 0. Linear scale. Units: unitless.
Cycle offset; Gate rising edges restart phase from this position. Range: 0–1 cycles. Default: 0 cycles. Linear scale. Units: cycles.
cycles
Pitch offset in cents. Range: -1200–1200 cents. Default: 0 cents. Linear scale. Units: cents.
cents
On or off. A rising edge retriggers; held on runs the oscillator or envelope. A control cable switches it at 0.5. Range: 0–1. Default: 1. Linear scale. Units: unitless.
Semitones a full pitch bend on the MIDI input moves the note, up or down. Range: 0–48 st. Default: 2 st. Linear scale. Units: st.
st
Time constant of the slide from one MIDI note's pitch to the next; 0 jumps. Range: 0–2000 ms. Default: 0 ms. Linear scale. Units: ms.
ms
Filter
Audio2ch
Audio2ch
Filter cutoff, capped at 0.45 times sample rate. Range: 20–20000 Hz. Default: 900 Hz. Logarithmic scale. Units: Hz.
Cascade a second stage and try the notch type on noise.
Noise
Audio2ch
Output level. Prepared per-mode gains balance continuous modes with headroom; sparse impulses retain their natural crest factor. Range: 0–0.5 ×. Default: 0.12 ×. Linear scale. Units: linear gain.
×
Eight colors and five textures. Discrete selection with a prepared, bounded transition; no numeric morphing between types. Range: 0–12. Default: 0. Linear scale. Units: unitless.
Output low-pass cutoff. The maximum setting is Open and bypasses the tone filter. Range: 200–20000 Hz. Default: 20000 Hz. Logarithmic scale. Units: Hz.
Hz
0 preserves path-derived deterministic streams. A positive integer selects another repeatable stream; each channel and nested instance stays independent. Range: 0–16777215. Default: 0. Linear scale. Units: unitless.
Filter
Audio2ch
Audio2ch
Filter cutoff, capped at 0.45 times sample rate. Range: 20–20000 Hz. Default: 1200 Hz. Logarithmic scale. Units: Hz.
Drive Four nonlinear shapers with DC removal, tone and latency-aligned filtered oversampling.
Oscillator Selected waveform kernels, continuous morphing, harmonic shapes and phase/gate control; an optional MIDI input plays notes in the Toy's tuning.
