diff --git a/viz/index.html b/viz/index.html
index 371522c..f16ee20 100644
--- a/viz/index.html
+++ b/viz/index.html
@@ -2448,6 +2448,10 @@
     return v;
   }
 
+  // Synth-side idle for the two dests whose "no value" default isn't 0 (see the
+  // d("filter.cutoff",0.3) / d("tempo.nudge",0.5) fallbacks). The cableless-tweak
+  // floor seeds THIS, so a neutral/reset knob returns a voice to its idle, not to 0.
+  const DEST_IDLE = { "filter.cutoff": 0.3, "tempo.nudge": 0.5 };
   let clientMatrix = false;          // true once the house patch has been cloned in
   function computeDests() {
     if (!clientMatrix) return;
@@ -2491,8 +2495,8 @@
     for (const k in destVals) destVals[k] = clamp(destVals[k], 0, 1);
     for (const k in notes) destVals[k] = notes[k];
     for (const [k, n] of dests) {              // any hand-tweaked cableless voice: emit its ACTUAL value —
-      if (n.isNote || (k in destVals)) continue;   // an offset floor gives it a level from nothing, and a
-      if (tweaks[k]) destVals[k] = 0;          // reset/mute/lower writes 0 too (else the last value sticks in the synth)
+      if (n.isNote || (k in destVals)) continue;   // an offset floor gives it a level from its idle, and a
+      if (tweaks[k]) destVals[k] = DEST_IDLE[k] || 0;   // reset/mute/lower re-emit too — seed the synth idle (not a blank 0), so a neutral filter/tempo doesn't pin dark
     }
     for (const k in destVals) {
       const tk = tweaks[k];
@@ -3500,7 +3504,7 @@
       const val = wrap.querySelector(".val"), dot = wrap.querySelector(".dot");
       if (!isNote) {
         let dragging = false, sy = 0, so = 0;
-        wrap.addEventListener("pointerdown", (e) => { if (e.button !== 0) return; dragging = true; sy = e.clientY; so = (tw(key).offset || 0); try { wrap.setPointerCapture(e.pointerId); } catch (x) {} e.preventDefault(); });
+        wrap.addEventListener("pointerdown", (e) => { if (e.button !== 0) return; dragging = true; sy = e.clientY; so = ((tweaks[key] && tweaks[key].offset) || 0); try { wrap.setPointerCapture(e.pointerId); } catch (x) {} e.preventDefault(); });
         wrap.addEventListener("pointermove", (e) => { if (!dragging) return; setParamLocal(key, "offset", clamp(so + (sy - e.clientY) / 150, -1, 1)); });
         const end = (e) => { dragging = false; try { wrap.releasePointerCapture(e.pointerId); } catch (x) {} if (zeroMode) zeroUI.persist(); };  // a knob shape is part of the zero build
         wrap.addEventListener("pointerup", end); wrap.addEventListener("pointercancel", end);
@@ -3519,7 +3523,7 @@
         const frac = n ? clamp(n.normDisp != null ? n.normDisp : (n.norm || 0), 0, 1) : 0;
         k.val.style.strokeDashoffset = (1000 * (1 - frac)).toFixed(1);
         if (!k.isNote) {
-          const off = tw(k.key).offset || 0;
+          const off = (tweaks[k.key] && tweaks[k.key].offset) || 0;   // read-only — don't create a neutral tweak just by rendering
           const a = (135 + ((off + 1) / 2) * 270) * Math.PI / 180;
           k.dot.setAttribute("cx", (50 + 34 * Math.cos(a)).toFixed(1));
           k.dot.setAttribute("cy", (50 + 34 * Math.sin(a)).toFixed(1));