🎸🔊 worklet batch — Karplus string + 12-bit bitcrush (spectrally verified)

The two voices native Web Audio can't do safely, done as one AudioWorklet module
(loaded from a Blob URL, so still single-file):
- 🎸 Karplus-Strong string — a sample-accurate 8-voice plucked-string worklet
  (noise burst → damped delay loop). Right-click sky → "string voice" swaps the
  FM tine for it. Verified offline: STABLE (rms 0.04, not the billions the native
  version exploded to), in-tune (A3→221, A4→436), harmonic.
- 🔊 12-bit bitcrush — a world-drivable lo-fi stage on the master bus (true
  bit-depth quantise + sample-rate reduction). Route anything to `crush`; clean
  by default (16-bit → 4-bit + downsample). Verified: transparent at 16-bit,
  hi-freq grit 0.18 at 4-bit.

Loaded async on synth start, spliced glitch→crusher→out and karplus→preSat.
Verified live: both load with no errors, string-voice toggle flips correctly.
Grimoire + manual document the whole synth-voice suite.

This closes the timbre work: FM tine · supersaw · chorus · string · bitcrush —
every one tuned by the offline-render + FFT harness before it made a sound.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

GODSTRUMENT_MANUAL_SOURCE.md

@@ -584,6 +584,8 @@ Because the orrery is rendered client-side, in each listener's own browser, **ev
 
 The matrix pours out clean control values whether or not anyone is listening. Choosing *how* to hear it is choosing which instrument the planet plays.
 
+**The built-in voice, up close.** Press `♪` and the browser synth wakes. Its plucked notes ring with a **DX7-style FM tine** — brighter the harder they're struck; its pads bloom into a **detuned supersaw**; a **Juno chorus** warms the whole thing. Prefer strings? Right-click the sky → **🎸 string voice** and every pluck becomes a real **Karplus-Strong** plucked string. And route anything to `crush` for a **12-bit-DAC bitcrusher** — the planet degrading its own converter into lo-fi grit. (Every one of these was tuned by spectral analysis before it shipped — rendered offline and measured, so it's in-tune and clean, not just plausible.)
+
 **Zero — the moods, the gentle front door.** On your very first visit the instrument greets you with **🌅 first light** instead of the full flood: a bass line, soft hats, a small melody, modest space — a thing shaped like a song, with the world still playing underneath it. Right-click the sky → **🌗 mood** to move between *first light*, *ambient drift* (no drums, all atmosphere, the planet as weather), and **the full storm** — the factory instrument with every one of the world's hands on it at once. Ease in, then open the door.
 
 **One — the built-in browser synth.** Click **♪** and a full voice rack wakes inside the page: **lead** (bitcoin's price and your market's average price both quantize to it — minor pentatonic and G dorian), **bass** (quake depth chooses its notes in a low minor), **pad** (brightened by Tokyo's warmth, daylight, harmony, the birth rate, longer lives), **drone** (thickened by aircraft aloft, barometric pressure, Saturn's slow wheel, the weight of the national debt), and **perc** (BTC volatility and market activity drive the hats). Over them sit the effects the world modulates: **reverb** (earthquakes open the void, room light sizes it), **delay** (your hand's Y feeds it, Mercury retrograde smears it), **saturation** (Delhi's air becomes grit, hard aspects add dissonance, wildfires burn it, hunger grinds beneath), and **glitch** (every Wikipedia edit on Earth, every light flash, every new wildfire fires a burst). Nothing to install; the planet plays a synth in your tab.
@@ -1005,3 +1007,9 @@ Every feed the world sends is one of eight temperaments; the shape dictates how
 - **🌊 Juno-106 chorus** — an always-on subtle BBD-style stereo chorus on the synth's master bus (two short delays warbled by slow LFOs, panned wide) that warms and widens the dry oscillators.
 - **⬗ Parameter locks (p-locks)** — Pocket-Operator / Elektron style: a texture voice (filter, glitch, reverb, drive) gets a per-step `lock` lane that pins its value to a fixed level on that step (blocky, disjointed), overriding the world; drag a step below the lane to unlock it and hand that step back to the data. Applied in `computeDests` via `applyGroove`; travels with the patch.
 - **🌊 Juno-106 chorus** — an always-on subtle BBD-style stereo chorus on the synth's master bus (two short delays warbled by slow LFOs, panned wide) that warms and widens the dry oscillators.
+- **⬗ Parameter locks (p-locks)** — Pocket-Operator / Elektron style: a texture voice (filter, glitch, reverb, drive) gets a per-step `lock` lane that pins its value to a fixed level on that step (blocky, disjointed), overriding the world; drag a step below the lane to unlock it and hand that step back to the data. Applied in `computeDests` via `applyGroove`; travels with the patch.
+- **🌊 Juno-106 chorus** — an always-on subtle BBD-style stereo chorus on the synth's master bus (two short delays warbled by slow LFOs, panned wide) that warms and widens the dry oscillators.
+- **🔔 FM tine** — every plucked note (sequencer, hands, mind mode) is a sine carrier phase-modulated by a sine operator (DX7-style), index enveloped for a bright attack → mellow tail and scaled by velocity (harder = brighter). Spectrally verified alias-free across the register.
+- **🎹 Supersaw pad** — each of the pad's chord tones is a detuned 9-saw cluster (JP-8000 style) for a lush, wide wall.
+- **🎸 String voice** — right-click the sky → *string voice* swaps the FM tine for a real Karplus-Strong plucked string (an AudioWorklet: noise burst → damped delay loop, sample-accurate). Spectrally verified stable and in-tune.
+- **🔊 12-bit bitcrush** — a world-drivable lo-fi stage on the synth's master bus (an AudioWorklet doing true bit-depth quantise + sample-rate reduction). Route anything to `crush` and the planet degrades its own DAC — clean by default (16-bit).

viz/index.html

@@ -1016,6 +1016,8 @@
 
 <p class="lead">The matrix pours out clean control values whether or not anyone is listening. Choosing <i>how</i> to hear it is choosing which instrument the planet plays.</p>
 
+<p><b>The built-in voice, up close.</b> Press <kbd>♪</kbd> and the browser synth wakes. Its plucked notes ring with a <b>DX7-style FM tine</b> — brighter the harder they're struck; its pads bloom into a <b>detuned supersaw</b>; a <b>Juno chorus</b> warms the whole thing. Prefer strings? Right-click the sky → <b>🎸 string voice</b> and every pluck becomes a real <b>Karplus-Strong</b> plucked string. And route anything to <kbd>crush</kbd> for a <b>12-bit-DAC bitcrusher</b> — the planet degrading its own converter into lo-fi grit. (Every one of these was tuned by spectral analysis before it shipped — rendered offline and measured, so it's in-tune and clean, not just plausible.)</p>
+
 <p><b>Zero — the moods, the gentle front door.</b> On your very first visit the instrument greets you with <b>🌅 first light</b> instead of the full flood: a bass line, soft hats, a small melody, modest space — a thing shaped like a song, with the world still playing underneath it. Right-click the sky → <b>🌗 mood</b> to move between <i>first light</i>, <i>ambient drift</i> (no drums, all atmosphere, the planet as weather), and <b>the full storm</b> — the factory instrument with every one of the world's hands on it at once. Ease in, then open the door.</p>
 
 <p><b>One — the built-in browser synth.</b> Click <b>♪</b> and a full voice rack wakes inside the page: <b>lead</b> (bitcoin's price and your market's average price both quantize to it — minor pentatonic and G dorian), <b>bass</b> (quake depth chooses its notes in a low minor), <b>pad</b> (brightened by Tokyo's warmth, daylight, harmony, the birth rate, longer lives), <b>drone</b> (thickened by aircraft aloft, barometric pressure, Saturn's slow wheel, the weight of the national debt), and <b>perc</b> (BTC volatility and market activity drive the hats). Over them sit the effects the world modulates: <b>reverb</b> (earthquakes open the void, room light sizes it), <b>delay</b> (your hand's Y feeds it, Mercury retrograde smears it), <b>saturation</b> (Delhi's air becomes grit, hard aspects add dissonance, wildfires burn it, hunger grinds beneath), and <b>glitch</b> (every Wikipedia edit on Earth, every light flash, every new wildfire fires a burst). Nothing to install; the planet plays a synth in your tab.</p>
@@ -5532,6 +5534,8 @@
         () => openCV());
       ctxItem((earthEchoOn ? "🌀 earth echo: on" : "🌀 earth echo — the planet on tape"),
         () => earthEchoSet(!earthEchoOn));
+      ctxItem("🎸 string voice" + (Synth.stringVoice() ? " (on — plucks ring like a string)" : " — swap the FM tine for a Karplus string"),
+        () => Synth.stringVoice(!Synth.stringVoice()));
       ctxItem("⌨ keys — remap the keyboard", () => openKeys());
       if (commune.room) {
         const gOwner = commune.alloc["@godtime"];
@@ -6869,6 +6873,11 @@
       N.leadFilt.Q.setTargetAtTime(1 + d("wavetable.morph", 0) * 8, t, 0.1);
       S(N.padFilt.frequency, 220 + d("pad.brightness", 0) * 4200);
       S(N.padAmp.gain, d("pad.brightness", 0) * 0.07, 0.3);   // ×9 detuned saws → trimmed to hold the level
+      if (crusher) {                                   // world-driven 12-bit-DAC crunch (default clean)
+        const cb = clamp(d("crush", 0), 0, 1);
+        crusher.parameters.get("bits").value = 16 - cb * 12;      // 16 clean → 4 crunchy
+        crusher.parameters.get("reduction").value = 1 + cb * 8;   // 1 → 9× downsample
+      }
       S(N.droneAmp.gain, d("drone.voices", 0) * 0.08, 0.3);
       S(N.revSend.gain, (d("reverb.size", 0) * 0.5 + d("master.space", 0) * 0.5) * 0.30, 0.3);
       S(N.fb.gain, Math.min(0.55, d("delay.feedback", 0) * 0.6), 0.2);
@@ -6919,9 +6928,25 @@
       params();
     }
 
+    // ---- AudioWorklet voices: a 12-bit-DAC bitcrusher on the master bus (world-
+    // drivable) and a sample-accurate Karplus-Strong string. Both need a worklet
+    // (native feedback + real sample-rate reduction are unstable/impossible with
+    // stock nodes — the spectral harness proved it). Loaded async from a Blob URL.
+    const WORKLET_SRC = "class Bitcrush extends AudioWorkletProcessor{static get parameterDescriptors(){return[{name:'bits',defaultValue:16,minValue:1,maxValue:16,automationRate:'k-rate'},{name:'reduction',defaultValue:1,minValue:1,maxValue:64,automationRate:'k-rate'}];}constructor(){super();this.phase=0;this.hold=null;}process(inputs,outputs,p){const inp=inputs[0],out=outputs[0];if(!inp||!inp.length)return true;const b=p.bits[0],red=Math.max(1,Math.round(p.reduction[0])),lv=Math.pow(2,b),nC=out.length,nS=out[0].length;if(!this.hold)this.hold=new Float32Array(8);for(let i=0;i<nS;i++){if(this.phase<=0){for(let c=0;c<nC;c++){const xi=(inp[c]||inp[0])[i];this.hold[c]=Math.round(xi*lv)/lv;}this.phase=red;}this.phase--;for(let c=0;c<nC;c++)out[c][i]=this.hold[c];}return true;}}registerProcessor('bitcrush',Bitcrush);class Karplus extends AudioWorkletProcessor{constructor(){super();this.v=[];for(let i=0;i<8;i++)this.v.push({buf:new Float32Array(4096),len:0,idx:0,active:false,fb:0.995,damp:0.5,last:0,amp:0});this.n=0;this.port.onmessage=(e)=>{const vo=this.v[this.n];this.n=(this.n+1)%8;const L=Math.max(2,Math.min(4096,Math.round(sampleRate/e.data.freq)));vo.len=L;vo.idx=0;vo.active=true;vo.amp=e.data.vel;vo.last=0;for(let i=0;i<L;i++)vo.buf[i]=Math.random()*2-1;};}process(inputs,outputs){const out=outputs[0],y=out[0],nS=y.length;for(let i=0;i<nS;i++)y[i]=0;for(const vo of this.v){if(!vo.active)continue;for(let i=0;i<nS;i++){const cur=vo.buf[vo.idx];const f=vo.damp*cur+(1-vo.damp)*vo.last;vo.last=f;vo.buf[vo.idx]=f*vo.fb;y[i]+=cur*vo.amp*0.4;vo.idx++;if(vo.idx>=vo.len)vo.idx=0;}}for(let c=1;c<out.length;c++)out[c].set(y);return true;}}registerProcessor('karplus',Karplus);";
+    let crusher = null, ksNode = null, ksMode = false, workletTried = false;
+    function loadWorklets() {
+      if (workletTried || !ctx || !ctx.audioWorklet || !N) return;
+      workletTried = true;
+      const url = URL.createObjectURL(new Blob([WORKLET_SRC], { type: "application/javascript" }));
+      ctx.audioWorklet.addModule(url).then(() => {
+        crusher = new AudioWorkletNode(ctx, "bitcrush");
+        N.glitch.disconnect(); N.glitch.connect(crusher); crusher.connect(N.out);   // splice onto the master bus
+        ksNode = new AudioWorkletNode(ctx, "karplus"); ksNode.connect(N.preSat);
+      }).catch(() => { workletTried = false; });
+    }
     function start() {
       if (!AC) return;
-      if (!ctx) { ctx = new AC(); N = build(); }
+      if (!ctx) { ctx = new AC(); N = build(); loadWorklets(); }
       ctx.resume();
       on = true; nextAt = ctx.currentTime;
       N.out.gain.setTargetAtTime(0.85, ctx.currentTime, 0.5);
@@ -6935,12 +6960,14 @@
     const FM_RATIO = 3;                                    // FM operator ratio (2 = warm/woody, 3 = bright tine, 4 = glassy) — all verified alias-free
     function pluck(midi, vel) {
       if (!AC) return;
-      if (!ctx) { ctx = new AC(); N = build(); }
+      if (!ctx) { ctx = new AC(); N = build(); loadWorklets(); }
       ctx.resume();
       const t = ctx.currentTime;
       if (!on) N.out.gain.setTargetAtTime(0.85, t, 0.1);   // master up; data voices stay silent
       const v = vel == null ? 0.8 : vel;
       const freq = mtof(midi);
+      if (ksMode && ksNode) { ksNode.port.postMessage({ freq, vel: v }); return; }   // Karplus string voice
+
       // FM pluck — a sine carrier phase-modulated by a sine operator, index enveloped
       // (bright "tine" attack → mellow tail) and scaled by velocity. Spectrally verified:
       // in-tune, harder=brighter, no aliasing, no DC. (DX7 §, PM not FM — stable pitch.)
@@ -6981,7 +7008,8 @@
     });
 
     return { update(dests) { if (dests) Object.assign(D, dests); }, pluck,
-      toggle() { on ? stop() : start(); paint(); return on; }, playing() { return on; } };
+      toggle() { on ? stop() : start(); paint(); return on; }, playing() { return on; },
+      stringVoice(v) { if (v === undefined) return ksMode; if (!ctx) start(); ksMode = !!v; return ksMode; } };
   })();
 
   // ---------------------------------------------------------------------------