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Procedural Analog Drum Synthesis Implementation #39

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40 changes: 17 additions & 23 deletions src/logic/DrumMachine.ts
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Expand Up @@ -50,14 +50,13 @@ export class DrumMachine {

this.comp.chain(this.shaper, this.output, Tone.Destination)

// Let's bypass compression for individual drum channels for now,
// to simplify routing and allow strict analog synth modeling.
// We'll route them directly to destination or output
this.outputKick.connect(Tone.Destination)
this.outputSnare.connect(Tone.Destination)
this.outputHihat.connect(Tone.Destination)
this.outputOpenHat.connect(Tone.Destination)
this.outputClap.connect(Tone.Destination)
// Connect all drum channels to the master compressor/shaper chain
// for the "glue effect" and analog saturation.
this.outputKick.connect(this.comp)
this.outputSnare.connect(this.comp)
this.outputHihat.connect(this.comp)
this.outputOpenHat.connect(this.comp)
this.outputClap.connect(this.comp)

this.kit808 = {
kick: new TR808Kick(this.outputKick),
Expand Down Expand Up @@ -101,26 +100,21 @@ export class DrumMachine {

if (this.currentKit === '808') {
switch (drum) {
case 'kick': kit808.kick.trigger(time, p.pitch, p.decay); break
case 'snare': kit808.snare.trigger(time, p.pitch, p.decay); break
case 'hihat': kit808.hihat.trigger(time, false, p.pitch, p.decay); break
case 'hihatOpen': kit808.hihat.trigger(time, true, p.pitch, p.decay); break
case 'clap': kit808.clap.trigger(time, p.pitch, p.decay); break
case 'kick': kit808.kick.trigger(time, p.pitch, p.decay, velocity); break
case 'snare': kit808.snare.trigger(time, p.pitch, p.decay, velocity); break
case 'hihat': kit808.hihat.trigger(time, false, p.pitch, p.decay, velocity); break
case 'hihatOpen': kit808.hihat.trigger(time, true, p.pitch, p.decay, velocity); break
case 'clap': kit808.clap.trigger(time, p.pitch, p.decay, velocity); break
}
} else {
switch (drum) {
case 'kick': kit909.kick.trigger(time, p.pitch, p.decay); break
case 'snare': kit909.snare.trigger(time, p.pitch, p.decay); break
case 'hihat': kit909.hihat.trigger(time, false, p.pitch, p.decay); break
case 'kick': kit909.kick.trigger(time, p.pitch, p.decay, velocity); break
case 'snare': kit909.snare.trigger(time, p.pitch, p.decay, velocity); break
case 'hihat': kit909.hihat.trigger(time, false, p.pitch, p.decay, velocity); break
case 'hihatOpen':
// Reuse hihat logic but specify it's open
// Note: technically TR909 uses samples for open hats, but we'll use our analog emulation for now
kit909.hihat.trigger(time, true, p.pitch, p.decay);
// However, we need to route it to the right output if possible. Our TR808HiHat
// currently has one destination baked in at constructor. To mix them separately,
// we will need an architectural tweak or just use the same channel. Let's just trigger it.
kit909.hihat.trigger(time, true, p.pitch, p.decay, velocity);
break
case 'clap': kit909.clap.trigger(time, p.pitch, p.decay); break
case 'clap': kit909.clap.trigger(time, p.pitch, p.decay, velocity); break
}
}
}
Expand Down
22 changes: 15 additions & 7 deletions src/logic/drums/TR808Clap.ts
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Expand Up @@ -10,27 +10,35 @@ export class TR808Clap {
for (let i = 0; i < data.length; i++) data[i] = Math.random() * 2 - 1;
}

trigger(time: number, pitch: number, decay: number) {
trigger(time: number, pitch: number, decay: number, velocity: number = 0.8) {
const noiseSrc = new Tone.BufferSource(this.noiseBuffer);
const bpf = new Tone.Filter(1000 + pitch * 1000, "bandpass");

// Micro-randomization: Filter Cutoff Variance (+/- 2%)
const cutoff = (1000 + pitch * 1000) * (1 + (Math.random() * 0.04 - 0.02));
const bpf = new Tone.Filter(cutoff, "bandpass");
const gain = new Tone.Gain(0).connect(this.destination);

noiseSrc.connect(bpf);
bpf.connect(gain);

// Triple attack "snaps"
const snapCount = 3;
const snapInterval = 0.01;
// Micro-randomization: Snap Intervals (+/- 2%)
const snapInterval = 0.01 * (1 + (Math.random() * 0.04 - 0.02));
for (let i = 0; i < snapCount; i++) {
const snapTime = time + i * snapInterval;
gain.gain.setValueAtTime(1, snapTime);
gain.gain.exponentialRampToValueAtTime(0.1, snapTime + snapInterval * 0.8);
// Velocity sensitivity: scale peak gain
gain.gain.setValueAtTime(velocity, snapTime);
gain.gain.exponentialRampToValueAtTime(0.1 * velocity, snapTime + snapInterval * 0.8);
}

// Final decay
const finalDecayStart = time + snapCount * snapInterval;
const decayTime = 0.1 + decay * 0.5;
gain.gain.setValueAtTime(1, finalDecayStart);
let decayTime = 0.1 + decay * 0.5;
// Micro-randomization: Decay Variance (+/- 2%)
decayTime *= (1 + (Math.random() * 0.04 - 0.02));

gain.gain.setValueAtTime(velocity, finalDecayStart);
gain.gain.exponentialRampToValueAtTime(0.001, finalDecayStart + decayTime);

noiseSrc.start(time).stop(finalDecayStart + decayTime);
Expand Down
25 changes: 18 additions & 7 deletions src/logic/drums/TR808HiHat.ts
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Expand Up @@ -5,11 +5,16 @@ export class TR808HiHat {

constructor(private destination: Tone.ToneAudioNode) { }

trigger(time: number, isOpen: boolean, pitch: number, decay: number) {
trigger(time: number, isOpen: boolean, pitch: number, decay: number, velocity: number = 0.8) {
// Create nodes
const mixGain = new Tone.Gain(0.15);
const bpf1 = new Tone.Filter(3440, "bandpass");
const bpf2 = new Tone.Filter(7100, "bandpass");

// Micro-randomization: Filter Cutoff Variance (+/- 2%)
const bpf1Freq = 3440 * (1 + (Math.random() * 0.04 - 0.02));
const bpf2Freq = 7100 * (1 + (Math.random() * 0.04 - 0.02));

const bpf1 = new Tone.Filter(bpf1Freq, "bandpass");
const bpf2 = new Tone.Filter(bpf2Freq, "bandpass");
const envGain = new Tone.Gain(0);
const hpf = new Tone.Filter(7000, "highpass");

Expand All @@ -18,8 +23,11 @@ export class TR808HiHat {

// Create 6 Square Wave Oscillators (Schmitt Trigger Matrix)
const oscillators = this.frequencies.map(freq => {
const drift = (Math.random() - 0.5) * 4; // Analog drift
// Analog drift: +/- 2Hz
const drift = (Math.random() - 0.5) * 4;
const osc = new Tone.Oscillator(freq * pitchMultiplier + drift, "square");
// Analog phase randomization: ensure each hit starts with random phase
osc.phase = Math.random() * 360;
osc.connect(mixGain);
return osc;
});
Expand All @@ -38,10 +46,13 @@ export class TR808HiHat {
bpf2.Q.value = 1.5;

// Decay: Closed Hat (40-60ms), Open Hat (300-500ms)
const decayTime = isOpen ? (0.3 + decay * 0.2) : (0.04 + decay * 0.02);
let decayTime = isOpen ? (0.3 + decay * 0.2) : (0.04 + decay * 0.02);

// Micro-randomization: Decay Variance (+/- 2%)
decayTime *= (1 + (Math.random() * 0.04 - 0.02));

// VCA Envelope
envGain.gain.setValueAtTime(1, time);
// VCA Envelope: scale by velocity
envGain.gain.setValueAtTime(velocity, time);
envGain.gain.exponentialRampToValueAtTime(0.001, time + decayTime);

// Scheduling
Expand Down
12 changes: 8 additions & 4 deletions src/logic/drums/TR808Kick.ts
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Expand Up @@ -3,11 +3,14 @@ import * as Tone from 'tone'
export class TR808Kick {
constructor(private destination: Tone.ToneAudioNode) { }

trigger(time: number, pitch: number, decay: number) {
trigger(time: number, pitch: number, decay: number, velocity: number = 0.8) {
// pitch: 0.5 -> 52.5Hz, maps to 45-60Hz range
const tune = 45 + pitch * 15;
// decay: 0.5 -> 1.7s, maps to 0.4-3.0s range
const decayTime = 0.4 + decay * 2.6;
let decayTime = 0.4 + decay * 2.6;

// Micro-randomization: Decay Variance (+/- 2%)
decayTime *= (1 + (Math.random() * 0.04 - 0.02));

// 808 Kick Core: Bridged-T Network emulation
const osc = new Tone.Oscillator(tune, "sine");
Expand All @@ -17,7 +20,7 @@ export class TR808Kick {
osc.connect(masterGain);
masterGain.connect(this.destination);

// Micro-randomization: Pitch Drift (+/- 1-2 cents or ~0.5Hz)
// Micro-randomization: Pitch Drift (+/- 0.5Hz)
const drift = (Math.random() * 2 - 1) * 0.5;

// Pitch Envelope: Start high (Tune * 2.5) and drop quickly to simulate the membrane hit ('tonk')
Expand All @@ -29,7 +32,8 @@ export class TR808Kick {
osc.frequency.exponentialRampToValueAtTime(endFreq, time + pitchDropTime);

// VCA Amp Envelope: Instant attack, adjustable exponential decay
masterGain.gain.setValueAtTime(1, time);
// Velocity sensitivity: scale peak gain
masterGain.gain.setValueAtTime(velocity, time);
masterGain.gain.exponentialRampToValueAtTime(0.001, time + decayTime);

osc.start(time).stop(time + decayTime);
Expand Down
25 changes: 18 additions & 7 deletions src/logic/drums/TR808Snare.ts
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Expand Up @@ -13,13 +13,19 @@ export class TR808Snare {
}
}

trigger(time: number, pitch: number, snappy: number) {
trigger(time: number, pitch: number, snappy: number, velocity: number = 0.8) {
// pitch maps to tone balance here (balance between low and high modes)
const toneBalance = pitch;

// Micro-randomization: Pitch Drift (+/- 1Hz)
const drift = (Math.random() * 2 - 1) * 1.0;

// 808 Membrane modes: fixed at ~238Hz and ~476Hz according to research
const oscLow = new Tone.Oscillator(238, "sine");
const oscHigh = new Tone.Oscillator(476, "sine");
const oscLow = new Tone.Oscillator(238 + drift, "sine");
const oscHigh = new Tone.Oscillator(476 + drift, "sine");
oscLow.phase = Math.random() * 360;
oscHigh.phase = Math.random() * 360;

const gainLow = new Tone.Gain(1 - toneBalance);
const gainHigh = new Tone.Gain(toneBalance);
const masterTonalGain = new Tone.Gain(0);
Expand All @@ -30,24 +36,29 @@ export class TR808Snare {
gainHigh.connect(masterTonalGain);
masterTonalGain.connect(this.destination);

masterTonalGain.gain.setValueAtTime(1, time);
// Velocity sensitivity: scale peak gain
masterTonalGain.gain.setValueAtTime(velocity, time);
// Tonal body decay is short (~200ms)
masterTonalGain.gain.exponentialRampToValueAtTime(0.001, time + 0.2);

// Snappy Layer
const noiseSrc = new Tone.BufferSource(this.noiseBuffer);
// High-pass filter (>1800Hz) to prevent phase trap with tonal body
const noiseFilter = new Tone.Filter(1800, "highpass");
// Micro-randomization: Filter Cutoff Variance (+/- 2%)
const noiseCutoff = 1800 * (1 + (Math.random() * 0.04 - 0.02));
const noiseFilter = new Tone.Filter(noiseCutoff, "highpass");
const snappyGain = new Tone.Gain(0);

noiseSrc.connect(noiseFilter);
noiseFilter.connect(snappyGain);
snappyGain.connect(this.destination);

// Snappy decay range: 0.25s to 0.4s
const snappyDecay = 0.25 + snappy * 0.15;
let snappyDecay = 0.25 + snappy * 0.15;
// Micro-randomization: Decay Variance (+/- 2%)
snappyDecay *= (1 + (Math.random() * 0.04 - 0.02));

snappyGain.gain.setValueAtTime(0.8, time);
snappyGain.gain.setValueAtTime(0.8 * velocity, time);
snappyGain.gain.exponentialRampToValueAtTime(0.001, time + snappyDecay);

oscLow.start(time).stop(time + 0.2);
Expand Down
21 changes: 14 additions & 7 deletions src/logic/drums/TR909Kick.ts
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Expand Up @@ -13,33 +13,40 @@ export class TR909Kick {
}
}

trigger(time: number, pitch: number, decay: number) {
trigger(time: number, pitch: number, decay: number, velocity: number = 0.8) {
// pitch: 0.5 -> 50Hz, maps to 45-55Hz
const tune = 45 + pitch * 10;
// decay: 0.5 -> 0.45s, maps to 0.3-0.6s
const decayTime = 0.3 + decay * 0.3;
let decayTime = 0.3 + decay * 0.3;

// Micro-randomization: Decay Variance (+/- 2%)
decayTime *= (1 + (Math.random() * 0.04 - 0.02));

// 909 Kick Body: Triangle Oscillator
const bodyOsc = new Tone.Oscillator(tune * 4.7, "triangle");
bodyOsc.phase = Math.random() * 360; // Analog phase randomization
const bodyGain = new Tone.Gain(0);

bodyOsc.connect(bodyGain);
bodyGain.connect(this.destination);

// Aggressive Pitch Envelope: Start at Tune * 4.7 (~235Hz) and drop over 100ms
const startFreq = tune * 4.7;
const endFreq = tune;
const drift = (Math.random() * 2 - 1) * 0.5; // Pitch Drift (+/- 0.5Hz)
const startFreq = tune * 4.7 + drift;
const endFreq = tune + drift;

bodyOsc.frequency.setValueAtTime(startFreq, time);
bodyOsc.frequency.exponentialRampToValueAtTime(endFreq, time + 0.1);

// VCA Envelope
bodyGain.gain.setValueAtTime(1, time);
// VCA Envelope: scale by velocity
bodyGain.gain.setValueAtTime(velocity, time);
bodyGain.gain.exponentialRampToValueAtTime(0.001, time + decayTime);

// Click Layer (Noise)
const noiseSrc = new Tone.BufferSource(this.noiseBuffer);
const noiseFilter = new Tone.Filter(1000, "highpass"); // HPF > 1kHz to avoid phase trap
// Micro-randomization: Filter Cutoff Variance (+/- 2%)
const noiseCutoff = 1000 * (1 + (Math.random() * 0.04 - 0.02));
const noiseFilter = new Tone.Filter(noiseCutoff, "highpass"); // HPF > 1kHz to avoid phase trap
const noiseGain = new Tone.Gain(0);

noiseSrc.connect(noiseFilter);
Expand Down
42 changes: 29 additions & 13 deletions src/logic/drums/TR909Snare.ts
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Expand Up @@ -14,43 +14,59 @@ export class TR909Snare {
}
}

trigger(time: number, pitch: number, snappy: number) {
trigger(time: number, pitch: number, snappy: number, velocity: number = 0.8) {
// 909 Snare Body: 2 triangle oscillators fixed at ~160Hz and ~220Hz
const freq1 = 160;
const freq2 = 220;

const osc1 = new Tone.Oscillator(freq1 * 2, "triangle");
const osc2 = new Tone.Oscillator(freq2 * 2, "triangle");
// Micro-randomization: Pitch Drift (+/- 1Hz)
const drift = (Math.random() * 2 - 1) * 1.0;

const osc1 = new Tone.Oscillator(freq1 * 2 + drift, "triangle");
const osc2 = new Tone.Oscillator(freq2 * 2 + drift, "triangle");
osc1.phase = Math.random() * 360;
osc2.phase = Math.random() * 360;

const tonalGain = new Tone.Gain(0);

osc1.connect(tonalGain);
osc2.connect(tonalGain);
tonalGain.connect(this.destination);

// 2x Pitch Sweep over 50ms
osc1.frequency.setValueAtTime(freq1 * 2, time);
osc1.frequency.exponentialRampToValueAtTime(freq1, time + 0.05);
osc2.frequency.setValueAtTime(freq2 * 2, time);
osc2.frequency.exponentialRampToValueAtTime(freq2, time + 0.05);
// 2x Pitch Sweep over 30ms (Adjusted based on research for TR-909 Snare)
const sweepTime = 0.03;
osc1.frequency.setValueAtTime(freq1 * 2 + drift, time);
osc1.frequency.exponentialRampToValueAtTime(freq1 + drift, time + sweepTime);
osc2.frequency.setValueAtTime(freq2 * 2 + drift, time);
osc2.frequency.exponentialRampToValueAtTime(freq2 + drift, time + sweepTime);

tonalGain.gain.setValueAtTime(1, time);
// Velocity sensitivity: scale peak gain
tonalGain.gain.setValueAtTime(velocity, time);
tonalGain.gain.exponentialRampToValueAtTime(0.001, time + 0.2);

// Snappy Layer
const noiseSrc = new Tone.BufferSource(this.noiseBuffer);
const hpf = new Tone.Filter(1000, "highpass"); // HPF to protect fundamental

// Micro-randomization: Filter Cutoff Variance (+/- 2%)
const hpfCutoff = 1000 * (1 + (Math.random() * 0.04 - 0.02));
const lpfCutoff = (4000 + pitch * 4000) * (1 + (Math.random() * 0.04 - 0.02));

const hpf = new Tone.Filter(hpfCutoff, "highpass"); // HPF to protect fundamental
// LPF controlled by 'Tone' (pitch parameter here), range 4kHz to 8kHz
const lpf = new Tone.Filter(4000 + pitch * 4000, "lowpass");
const lpf = new Tone.Filter(lpfCutoff, "lowpass");
const noiseGain = new Tone.Gain(0);

noiseSrc.connect(hpf);
hpf.connect(lpf);
lpf.connect(noiseGain);
noiseGain.connect(this.destination);

const snappyDecay = 0.1 + snappy * 0.4;
// Snappy decay range: 0.1s to 0.5s
let snappyDecay = 0.1 + snappy * 0.4;
// Micro-randomization: Decay Variance (+/- 2%)
snappyDecay *= (1 + (Math.random() * 0.04 - 0.02));

noiseGain.gain.setValueAtTime(0.7, time);
noiseGain.gain.setValueAtTime(0.7 * velocity, time);
noiseGain.gain.exponentialRampToValueAtTime(0.001, time + snappyDecay);

osc1.start(time).stop(time + 0.2);
Expand Down
8 changes: 4 additions & 4 deletions src/store/instrumentStore.ts
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Expand Up @@ -33,11 +33,11 @@ interface DrumState {

export const useDrumStore = create<DrumState>((set) => ({
kick: { steps: 16, pulses: 4, rotate: 0, decay: 0.5, pitch: 0.5 },
snare: { steps: 16, pulses: 0, rotate: 0, decay: 0.5, pitch: 0.5 },
hihat: { steps: 16, pulses: 8, rotate: 0, decay: 0.5, pitch: 0.5 },
hihatOpen: { steps: 16, pulses: 0, rotate: 0, decay: 0.5, pitch: 0.5 },
snare: { steps: 16, pulses: 2, rotate: 4, decay: 0.5, pitch: 0.5 },
hihat: { steps: 16, pulses: 12, rotate: 0, decay: 0.5, pitch: 0.5 },
hihatOpen: { steps: 16, pulses: 2, rotate: 2, decay: 0.5, pitch: 0.5 },
clap: { steps: 16, pulses: 0, rotate: 0, decay: 0.5, pitch: 0.5 },
kit: '808',
kit: '909',
setParams: (drum, params) => set((state) => ({
[drum]: { ...state[drum], ...params }
})),
Expand Down