feat(gallery): rebuild R05 filter bank with three skin axes

The old card was a sketch: eight bare tracks and flat teal arrows floating on the card background. Real slider banks (the Vieltronix filter, the Pioneer SG-9500, the Technics SH-8065, the Zaxcom Oasis) have a faceplate, dual dB rails, dense bands, and caps that read as machined parts.

The rebuilt bank draws twelve bands on a screwed faceplate with tick rails both sides. Skins ship as constructor opts backed by GW.filterBank.STYLES on three independent axes: panel (lab parchment / silver aluminum / studio black), cap shape (tall block fader / short ribbed / chrome T), and cap color (black white-index / red, green, blue, amber stripes / chrome / cream). Shape and color are separate axes so any finish applies to any cap. opts.style picks a native trio. setStyle(axis, name) restyles a live instance with values preserved. The card grows chip groups driving setStyle, the same demo-rig pattern as the slide toggle.

Values shorter than a custom freqs list now pad instead of placing caps at NaN. I filed the Oasis reference alongside the others.

3 files changed, 137 insertions, 29 deletions

diff --git a/docs/prototypes/panel-widget-gallery.html b/docs/prototypes/panel-widget-gallery.html
index 30bf086..0674302 100644
--- a/docs/prototypes/panel-widget-gallery.html
+++ b/docs/prototypes/panel-widget-gallery.html
@@ -1127,7 +1127,7 @@ card(C,'R04','Bakelite fluted knob',
   '<b>the skirted console knob.</b> Scalloped bakelite skirt, glossy dome, amber index over a printed 0-10 scale. Drag up/down to turn. After a vintage console mixer knob.');
 card(C,'R05','Filter slider bank',
   (st,rd)=>GW.filterBank(st,{onChange:(v,t)=>rd(t)}),
-  '<b>a wall of band faders.</b> One slider per band, arrow-head caps on black tracks, dB rail at the side. Drag any cap; readout names band and level. After a variable multi-band filter.');
+  '<b>a wall of band faders.</b> Twelve bands on a screwed faceplate, dB rails both sides. Drag any cap; readout names band and level. Skins split three independent axes — panel (lab parchment after the Vieltronix filter / silver hi-fi after the Pioneer SG-9500 / studio black after the Technics SH-8065), cap shape (tall block fader after the Zaxcom Oasis / short ribbed / chrome T), and cap color (black white-index / red / green / blue / amber stripes / chrome / cream). The chips below mix them freely.');
 card(C,'R06','Chicken-head selector',
   (st,rd)=>GW.chickenHead(st,{index:2,onChange:(i,t)=>rd(t)}),
   '<b>the pointer-lever switch.</b> The tapered bakelite lever IS the indicator — it aims at the engraved position. Click to step through. After a modulator mode switch.');
@@ -1541,6 +1541,25 @@ BOOST.forEach(no=>{const rd=document.getElementById('rd-'+no);
       g.appendChild(b);}
     row.appendChild(g);}
   cardEl.querySelector('.opts').appendChild(row);})();
+
+/* filter-bank style chips: demo rig for GW.filterBank's constructor opts —
+   the named skins live in GW.filterBank.STYLES; chips drive setStyle on the live instance */
+(function(){const h=$('card-R05')?.gw;if(!h)return;
+  const cardEl=h.el.closest('.card');
+  const row=document.createElement('div'); row.className='famchips';
+  const AXES=[['panel','panel','lab'],['shape','caps','block'],['color','capColor','black']];
+  for(const [label,axis,def] of AXES){
+    const g=document.createElement('span'); g.className='fgroup';
+    const lab=document.createElement('span'); lab.className='lab'; lab.textContent=label; g.appendChild(lab);
+    const chips=[];
+    for(const [name,o] of Object.entries(GW.filterBank.STYLES[axis])){
+      const b=document.createElement('span'); b.className='fc'+(name===def?' on':'');
+      b.style.background=o.dot; b.title=name; chips.push(b);
+      b.addEventListener('click',()=>{h.setStyle(axis,name);
+        chips.forEach(x=>x.classList.toggle('on',x===b));});
+      g.appendChild(b);}
+    row.appendChild(g);}
+  cardEl.querySelector('.opts').appendChild(row);})();
 </script>
 </body>
 </html>
diff --git a/docs/prototypes/widgets.js b/docs/prototypes/widgets.js
index c01972e..53217ec 100644
--- a/docs/prototypes/widgets.js
+++ b/docs/prototypes/widgets.js
@@ -676,41 +676,130 @@ GW.flutedKnob = function (host, opts = {}) {
   return { el: s, get: () => val, set };
 };
 
-/* R05 filter slider bank — one fader per band, teal arrow caps on black tracks */
+/* R05 filter slider bank — a dense fader wall on a real faceplate. Period skins
+   as constructor opts backed by GW.filterBank.STYLES, three independent axes:
+   panel (lab parchment / silver hi-fi aluminum / studio black), caps — the cap
+   SHAPE (chrome T / short ribbed / tall block fader), and capColor — the cap
+   FINISH (black white-index / red-index / chrome / cream). opts.style picks a
+   native trio (lab+block+black, silver+chrome+chrome, studio+ribbed+red);
+   opts.panel / opts.caps / opts.capColor override an axis; setStyle(axis, name)
+   restyles live (values kept). After the Vieltronix filter, the Pioneer
+   SG-9500, the Technics SH-8065, and the Zaxcom Oasis block faders. */
 GW.filterBank = function (host, opts = {}) {
   const onChange = opts.onChange || noop;
-  const freqs = opts.freqs || [78, 136, 235, 406, 701, 1210, 2090, 3620];
-  const vals = (opts.values || [18, 30, 42, 25, 35, 55, 20, 48]).slice();
-  const fmtHz = f => f < 1000 ? f : (f / 1000) + 'k';
-  const s = stageSvg(host, 'rsvg', 190, 96);
-  const y0 = 14, y1 = 84, x0 = 30, dx = 19.5;
-  for (const [lbl, y] of [['0', y0], ['20', y0 + (y1 - y0) / 3], ['40', y0 + 2 * (y1 - y0) / 3], ['60', y1]])
-    svgEl(s, 'text', { x: 14, y: y + 2, 'text-anchor': 'end', 'font-size': 6, 'font-family': 'var(--mono)', fill: 'var(--steel)' }).textContent = lbl;
-  svgEl(s, 'text', { x: 14, y: 94, 'text-anchor': 'end', 'font-size': 5.5, 'font-family': 'var(--mono)', fill: 'var(--dim)' }).textContent = 'dB';
+  const freqs = opts.freqs || [78, 113, 163, 235, 339, 487, 701, 1010, 1450, 2090, 3010, 4340];
+  const vals = (opts.values || [18, 30, 42, 25, 35, 55, 20, 48, 38, 26, 44, 32]).slice(0, freqs.length);
+  while (vals.length < freqs.length) vals.push(30);
+  const fmtHz = f => f < 1000 ? f : (f / 1000).toFixed(1).replace(/\.0$/, '') + 'k';
+  const ST = GW.filterBank.STYLES;
+  const native = {
+    lab: { caps: 'block', capColor: 'black' },
+    silver: { caps: 'chrome', capColor: 'chrome' },
+    studio: { caps: 'ribbed', capColor: 'red' },
+  };
+  const nat = native[opts.style] || {};
+  const cur = {
+    panel: ST.panel[opts.panel] ? opts.panel : (ST.panel[opts.style] ? opts.style : 'lab'),
+    caps: ST.caps[opts.caps] ? opts.caps : (nat.caps || 'block'),
+    capColor: ST.capColor[opts.capColor] ? opts.capColor : (nat.capColor || 'black'),
+  };
+  gradDef('fbPlateLab', 'linearGradient', { x1: 0, y1: 0, x2: 0, y2: 1 }, [['0', '#f0ead6'], ['1', '#dcd5bc']]);
+  gradDef('fbPlateSilver', 'linearGradient', { x1: 0, y1: 0, x2: 0, y2: 1 }, [['0', '#d8d8d4'], ['.5', '#c6c6c1'], ['1', '#adada7']]);
+  gradDef('fbPlateStudio', 'linearGradient', { x1: 0, y1: 0, x2: 0, y2: 1 }, [['0', '#221f1c'], ['1', '#131110']]);
+  gradDef('sfChrome', 'linearGradient', { x1: 0, y1: 0, x2: 0, y2: 1 }, [['0', '#f0efec'], ['.45', '#c4c1b9'], ['1', '#75726a']]);
+  gradDef('fbCapBlack', 'linearGradient', { x1: 0, y1: 0, x2: 0, y2: 1 }, [['0', '#2a2724'], ['1', '#171412']]);
+  gradDef('fbCapCream', 'linearGradient', { x1: 0, y1: 0, x2: 0, y2: 1 }, [['0', '#f2ecd8'], ['1', '#cfc8ae']]);
+  const s = stageSvg(host, 'rsvg', 250, 112);
+  const y0 = 20, y1 = 92, x0 = 36, dx = (214 - x0) / (freqs.length - 1);
+  const yOf = db => y0 + db / 60 * (y1 - y0);
   const caps = [];
+  const place = i => caps[i].setAttribute('transform', `translate(0,${yOf(vals[i])})`);
+  const drawCap = (g, kind, x) => {
+    const c = ST.capColor[cur.capColor];
+    if (kind === 'chrome') {
+      svgEl(g, 'rect', { x: x - 6, y: -3.25, width: 12, height: 6.5, rx: .9, fill: c.body, stroke: c.edge, 'stroke-width': .6 });
+      svgEl(g, 'line', { x1: x - 6, y1: 0, x2: x + 6, y2: 0, stroke: c.index, 'stroke-width': 1 });
+      svgEl(g, 'line', { x1: x - 6, y1: 2, x2: x + 6, y2: 2, stroke: c.rib, 'stroke-width': .5 });
+    } else if (kind === 'ribbed') {
+      svgEl(g, 'rect', { x: x - 5, y: -4, width: 10, height: 8, rx: 1, fill: c.body, stroke: c.edge, 'stroke-width': .6 });
+      for (const dy of [-2.4, 2.4])
+        svgEl(g, 'line', { x1: x - 4, y1: dy, x2: x + 4, y2: dy, stroke: c.rib, 'stroke-width': .6 });
+      svgEl(g, 'line', { x1: x - 5, y1: 0, x2: x + 5, y2: 0, stroke: c.index, 'stroke-width': 1.1 });
+    } else { /* block — tall ribbed fader after the Zaxcom Oasis; fine rib
+      groups above and below a mid-cap index line that marks the value */
+      svgEl(g, 'rect', { x: x - 4.5, y: -8, width: 9, height: 16, rx: 1.1, fill: c.body, stroke: c.edge, 'stroke-width': .6 });
+      for (const dy of [-6.4, -4.8, -3.2, -1.6, 1.6, 3.2, 4.8, 6.4])
+        svgEl(g, 'line', { x1: x - 3.7, y1: dy, x2: x + 3.7, y2: dy, stroke: c.rib, 'stroke-width': .6 });
+      svgEl(g, 'line', { x1: x - 4.5, y1: 0, x2: x + 4.5, y2: 0, stroke: c.index, 'stroke-width': 1.2 });
+    }
+  };
   const set = (i, db) => {
-    db = Math.max(0, Math.min(60, db)); vals[i] = db;
-    caps[i].setAttribute('transform', `translate(0,${14 + db / 60 * 70})`);
+    db = Math.max(0, Math.min(60, db)); vals[i] = db; place(i);
     onChange({ band: i, hz: freqs[i], db }, `${fmtHz(freqs[i])} Hz · −${Math.round(db)} dB`);
   };
-  freqs.forEach((f, i) => {
-    const x = x0 + i * dx;
-    svgEl(s, 'text', { x, y: 8, 'text-anchor': 'middle', 'font-size': 5.2, 'font-family': 'var(--mono)', fill: 'var(--steel)' }).textContent = fmtHz(f);
-    svgEl(s, 'line', { x1: x, y1: y0, x2: x, y2: y1, stroke: '#0a0908', 'stroke-width': 3.4, 'stroke-linecap': 'round' });
-    svgEl(s, 'line', { x1: x - .7, y1: y0, x2: x - .7, y2: y1, stroke: 'rgba(255,255,255,.05)', 'stroke-width': .7 });
-    const cap = svgEl(s, 'g', {});
-    svgEl(cap, 'polygon', { points: `${x - 8.5},${-4.5} ${x - 2.5},0 ${x - 8.5},${4.5}`, fill: 'var(--vfd)', stroke: '#123028', 'stroke-width': .6 });
-    svgEl(cap, 'polygon', { points: `${x + 8.5},${-4.5} ${x + 2.5},0 ${x + 8.5},${4.5}`, fill: 'var(--vfd)', stroke: '#123028', 'stroke-width': .6 });
-    svgEl(cap, 'circle', { cx: x, cy: 0, r: 1.5, fill: '#123028' });
-    caps.push(cap);
-    /* paint the initial position without announcing it */
-    cap.setAttribute('transform', `translate(0,${14 + vals[i] / 60 * 70})`);
-    const hit = svgEl(s, 'rect', { x: x - 9.5, y: y0 - 6, width: 19, height: y1 - y0 + 12, fill: 'transparent' });
-    hit.style.cursor = 'ns-resize';
-    dragY(hit, pct => set(i, (100 - pct) / 100 * 60));
-  });
+  const render = () => {
+    const st = ST.panel[cur.panel];
+    s.replaceChildren(); caps.length = 0;
+    svgEl(s, 'rect', { x: 1.5, y: 1.5, width: 247, height: 109, rx: 5, fill: st.plate, stroke: st.edge, 'stroke-width': 1 });
+    svgEl(s, 'rect', { x: 3, y: 3, width: 244, height: 106, rx: 4, fill: 'none', stroke: st.bevel, 'stroke-width': .7 });
+    [[9, 9], [241, 9], [9, 103], [241, 103]].forEach(([sx, sy], k) => {
+      svgEl(s, 'circle', { cx: sx, cy: sy, r: 2.7, fill: st.screw, stroke: 'rgba(0,0,0,.55)', 'stroke-width': .6 });
+      svgEl(s, 'line', { x1: sx - 1.9, y1: sy, x2: sx + 1.9, y2: sy, stroke: 'rgba(0,0,0,.6)', 'stroke-width': .7, transform: `rotate(${25 + k * 40},${sx},${sy})` });
+    });
+    for (let db = 0; db <= 60; db += 10) {
+      const y = yOf(db), major = db % 20 === 0, len = major ? 4 : 2.5;
+      svgEl(s, 'line', { x1: 24 - len, y1: y, x2: 24, y2: y, stroke: st.dim, 'stroke-width': major ? .9 : .6 });
+      svgEl(s, 'line', { x1: 226, y1: y, x2: 226 + len, y2: y, stroke: st.dim, 'stroke-width': major ? .9 : .6 });
+      if (major) {
+        svgEl(s, 'text', { x: 17, y: y + 2, 'text-anchor': 'end', 'font-size': 5.2, 'font-family': 'var(--mono)', fill: st.ink }).textContent = db;
+        svgEl(s, 'text', { x: 233, y: y + 2, 'text-anchor': 'start', 'font-size': 5.2, 'font-family': 'var(--mono)', fill: st.ink }).textContent = db;
+      }
+    }
+    svgEl(s, 'text', { x: 20, y: 100, 'text-anchor': 'end', 'font-size': 4.6, 'font-family': 'var(--mono)', fill: st.dim }).textContent = 'dB';
+    freqs.forEach((f, i) => {
+      const x = x0 + i * dx;
+      svgEl(s, 'text', { x, y: 13, 'text-anchor': 'middle', 'font-size': 4.6, 'font-family': 'var(--mono)', fill: st.ink }).textContent = fmtHz(f);
+      svgEl(s, 'line', { x1: x, y1: y0, x2: x, y2: y1, stroke: st.track, 'stroke-width': st.trackW, 'stroke-linecap': 'round' });
+      if (st.trackHi) svgEl(s, 'line', { x1: x - st.trackW / 2 - .35, y1: y0, x2: x - st.trackW / 2 - .35, y2: y1, stroke: st.trackHi, 'stroke-width': .7 });
+      const cap = svgEl(s, 'g', {});
+      drawCap(cap, cur.caps, x);
+      caps.push(cap); place(i);
+      const hit = svgEl(s, 'rect', { x: x - dx / 2, y: y0 - 6, width: dx, height: y1 - y0 + 12, fill: 'transparent' });
+      hit.style.cursor = 'ns-resize';
+      dragY(hit, pct => set(i, (100 - pct) / 100 * 60));
+    });
+  };
+  const setStyle = (axis, name) => {
+    if (!ST[axis] || !ST[axis][name]) return;
+    cur[axis] = name; render();
+  };
+  render();
   onChange(null, 'drag a band');
-  return { el: s, get: () => vals.slice(), set };
+  return { el: s, get: () => vals.slice(), set, setStyle };
+};
+/* named styles per axis: dot = swatch color for pickers. caps is the cap
+   shape; capColor is the cap finish (body + rib + index line), applicable to
+   any shape. */
+GW.filterBank.STYLES = {
+  panel: {
+    lab: { dot: '#e9e4cf', plate: 'url(#fbPlateLab)', edge: '#b7b29a', bevel: 'rgba(255,255,255,.35)', ink: '#3a3128', dim: '#6a6152', screw: '#a8a496', track: '#0c0b09', trackW: 2.4, trackHi: null },
+    silver: { dot: '#c9c9c5', plate: 'url(#fbPlateSilver)', edge: '#8e8e88', bevel: 'rgba(255,255,255,.4)', ink: '#33332f', dim: '#5c5c56', screw: '#9c9c96', track: '#121210', trackW: 2.0, trackHi: null },
+    studio: { dot: '#1c1a18', plate: 'url(#fbPlateStudio)', edge: '#000', bevel: 'rgba(255,255,255,.06)', ink: '#b9b4a6', dim: '#6f6a5e', screw: '#3c3832', track: '#050505', trackW: 2.2, trackHi: 'rgba(255,255,255,.05)' },
+  },
+  caps: {
+    block: { dot: '#2c2824' },
+    ribbed: { dot: '#6f6a5e' },
+    chrome: { dot: '#dfe6f2' },
+  },
+  capColor: {
+    black: { dot: '#211e1b', body: 'url(#fbCapBlack)', rib: 'rgba(255,255,255,.16)', index: '#f2f4f2', edge: '#000' },
+    red: { dot: 'var(--sevred)', body: 'url(#fbCapBlack)', rib: 'rgba(255,255,255,.16)', index: 'var(--sevred)', edge: '#000' },
+    green: { dot: 'var(--sevgrn)', body: 'url(#fbCapBlack)', rib: 'rgba(255,255,255,.16)', index: 'var(--sevgrn)', edge: '#000' },
+    blue: { dot: '#4f9fe0', body: 'url(#fbCapBlack)', rib: 'rgba(255,255,255,.16)', index: '#4f9fe0', edge: '#000' },
+    amber: { dot: 'var(--gold-hi)', body: 'url(#fbCapBlack)', rib: 'rgba(255,255,255,.16)', index: 'var(--gold-hi)', edge: '#000' },
+    chrome: { dot: '#dfe6f2', body: 'url(#sfChrome)', rib: 'rgba(0,0,0,.28)', index: '#14110e', edge: '#3c3a34' },
+    cream: { dot: '#efe9d4', body: 'url(#fbCapCream)', rib: 'rgba(0,0,0,.18)', index: '#3a3128', edge: '#8a8474' },
+  },
 };
 
 /* R06 chicken-head selector — tapered lever aims at the position */
diff --git a/working/retro-stereo-widgets/references/2026-07-12-oasis-fader-bank.png b/working/retro-stereo-widgets/references/2026-07-12-oasis-fader-bank.png
new file mode 100644
index 0000000..cb0174f
--- /dev/null
+++ b/working/retro-stereo-widgets/references/2026-07-12-oasis-fader-bank.png