The Modulation Matrix
Any source → any destination with adjustable depth. This is how modern synths work: a grid replaces hardwired connections.
Beyond Hardwired
Every synth so far had fixed routing: an LFO always controlled pitch, an envelope always controlled the filter. A modulation matrix makes every connection configurable. Pick a source, pick a destination, set a depth. Done.
Sources and Destinations
Sources produce control signals that change over time:
- LFO 1 & 2, repeating waves (sine, triangle). Rate controls speed.
- Envelope, a one-shot ADSR shape, triggered with each note. Attack sets how fast it rises, decay how fast it falls.
- Random: imagine rolling a die on every sequencer step. The value jumps instantly to a new random number, then holds steady until the next step fires. This is sample and hold (Part 16); the sequencer is the clock, and each tick picks a new value. Use the Scale selector to quantize the random jumps to musical intervals (pentatonic, major, etc.) so random pitch modulation stays in key.
- Noise, raw noise that outputs a random value every sample, much faster than Random. Use it for texture and grit.
- Offset, a fixed constant (default 0). It doesn't change over time; set it to permanently bias a parameter up or down. For example, +50% on LP Cut raises the filter baseline.
Destinations are the parameters these sources can control: pitch, three independent filter cutoffs (lowpass, highpass, bandpass), resonance (Q), volume, and panning. The three filters run in series; LP is always active, while HP and BP only engage when modulated. Drag the slider in each cell to set how much that source affects that destination. Positive values push the parameter up, negative pull it down.
Try it: click a cell where LFO 1 meets Pitch to add vibrato. Click again for more depth. Try "HPF Sweep" to hear highpass modulation.