{
  "format": "circuit-codex-reference",
  "version": 1,
  "id": "5e6a",
  "url": "https://circuitcodex.com/amps/5e6a/",
  "attribution": "The Analog Maker / Circuit Codex",
  "license": "https://creativecommons.org/licenses/by-sa/4.0/",
  "revision": "ebddc3fd2cf887dca010bbe60487d7391ea6c052",
  "scope": "DC and drawing checks have separate coverage. See included check results and the circuit page; not a dimensioned build template or a physical-build certification.",
  "metadata": {
    "id": "5e6a",
    "name_style": "Tweed Bassman-style",
    "family": "tweed",
    "era": {
      "start": 1956,
      "end": 1957
    },
    "wattage": 40,
    "tubes": [
      "12AY7",
      "12AY7",
      "12AX7",
      "6L6G",
      "6L6G",
      "5U4GA",
      "5U4GA"
    ],
    "topology": {
      "rectifier": {
        "kind": "tube",
        "type": "5U4GA",
        "count": 2,
        "note": "two rectifier tubes in parallel, each HT lead to one plate of each bottle, into a 16 µF can and then a choke"
      },
      "bias": "fixed",
      "phase_inverter": "cathodyne",
      "tone_stack": "cathode-follower-tb"
    },
    "lineage": {
      "derived_from": [],
      "influenced": [
        "5f6"
      ]
    },
    "conventions": {
      "designators": "functional"
    },
    "sources": [
      {
        "desc": "Fender \"Bass-Man\" Schematic, Model 5E6-A (drawing code A-EE): every component value, the stage chain and the printed voltage chart read from the published schematic at its native 6363 × 4071. A 12AY7 two-channel input (1 MEG grid leaks, no stoppers; 100 kΩ plates at +130 V; shared 820 Ω / 250 µF cathode at +2 V; 0.0001 µF bright cap across the first Volume); a second 12AY7 split into a gain stage (100 kΩ plate at +130 V, 1.5 kΩ / 25 µF cathode at +2 V) direct-coupled to a cathode follower (100 kΩ cathode load at +130 V); a treble/bass network fed from the follower's cathode (0.1 µF, 220 kΩ to ground and 10 MEG back to the gain stage's grid, 220 kΩ to the Bass wiper with 0.005 µF under it, 220 kΩ to the Treble wiper; 250 pF into the Treble with 0.01 µF · 400 V under it); a 12AX7 driver (100 kΩ plate at +200 V, 1.5 kΩ cathode at +1.7 V, with the 20 kΩ feedback resistor and the 5 kΩ Presence on that cathode) into a split-load cathodyne (56 kΩ plate at +260 V; 1.5 kΩ + 56 kΩ cathode at +72 V; 1 MEG grid leak to the junction); 0.1 µF couplers onto 220 kΩ leaks from −42 V and 1.5 kΩ stoppers into a fixed-bias 6L6G pair (plates +405 V). Supply: two 5U4GA in parallel, 16 µF at +420 V, a choke, two 16 µF at +410 V (screens and the OT centre tap), 10 kΩ to +335 V, 10 kΩ to +275 V; bias from an HT-winding tap through 3300 Ω and a selenium rectifier to −42 V with 100 µF and 56 kΩ. Not reproduced here; archived at EL34World.",
        "url": "https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_5e6a.pdf"
      },
      {
        "desc": "Fender \"Bass-Man\" Layout, Model 5E6-A (A-EE), page 1, read at its native 6463 × 3809: the board's parts in order, the socket wiring (the second 12AY7's 100 kΩ plate load across its socket from pin 6 to pin 1 with a pin 7 to pin 1 jumper; the 12AX7's +200 V driver plate on pin 1 and +260 V cathodyne plate on pin 6; each 6L6G's 1.5 kΩ stopper on the socket), the choke's two leads rising to the +420 V and +410 V cans, the tone parts at the controls, and the printed +70 V at the cathodyne's resistor junction. It letters three parts differently from the schematic page: one mixer 250 K, the Treble's bleed capacitor 600 V, and a 47 MMF across the Treble control that the schematic page does not draw. Not reproduced here; archived at EL34World.",
        "url": "https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_5e6a.pdf"
      },
      {
        "desc": "Fender \"Bass-Man\" Schematic, Model 5E6 (same A-EE drawing code as the 5E6-A) — read side by side with the 5E6-A to date the one substantive change: a handwritten note on the 5E6 sheet by the bias-supply resistor reads \"THIS CHANGE TO INCREASE BIAS ON PLATES SO WON'T GET HOT\", with the resistor's value struck through; the 5E6-A drawing prints the changed value (3300 Ω) cleanly with no annotation, confirming the -A suffix marks that fix landing. A lower series resistor ahead of this bias rectifier delivers a more negative (larger-magnitude) bias, consistent with the note's stated intent of reducing 6L6G plate dissipation.",
        "url": "https://el34world.com/charts/Schematics/files/Fender/Fender_bassman_5e6.pdf"
      },
      {
        "desc": "Schematic Heaven, Fender Bassman 5E6-A schematic + layout scan — a second archived copy of the same A-EE drawing.",
        "url": "https://schematicheaven.net/fenderamps/bassman_5e6a_schem.pdf"
      },
      {
        "desc": "Wikipedia, \"Fender Bassman\" — dates the 5E6/5E6-A narrow-panel dual- rectifier 4x10 circuits to 1955-1957 as evolutionary refinements of the 5D6; this corpus entry uses the defensible later portion of that range (1956-1957) for the -A revision specifically, since no source gives a clean split between 5E6 and 5E6-A production dates (see the Bassman family page).",
        "url": "https://en.wikipedia.org/wiki/Fender_Bassman"
      }
    ],
    "verification": {
      "status": "draft"
    },
    "added": "2026-08-08T00:00:00.000Z",
    "contributors": [
      "TheAnalogMaker"
    ]
  },
  "parts": {
    "notes": "The two rectifier tubes (V6/V7) are not DC-modelled: an ideal B+ source stands in for the rectifier and power transformer, the corpus convention. The volume controls, the tone network's pots and every capacitor inside that network sit off the DC model's path too (DC-open or pot-dependent), though each carries its own designator. The 47 pF across the Treble control (C8) is lettered on the layout page only; the schematic page does not draw it. Parts with no designator are the mains and supply hardware the schematic draws as annotation.",
    "items": [
      {
        "ref": "RG1",
        "part": "Carbon comp resistor",
        "value": "1 MΩ · ½ W",
        "role": "Bright-channel input grid leak, mounted at the input jack"
      },
      {
        "ref": "RG2",
        "part": "Carbon comp resistor",
        "value": "1 MΩ · ½ W",
        "role": "Normal-channel input grid leak, mounted at the input jack"
      },
      {
        "ref": "RL1",
        "part": "Carbon comp resistor",
        "value": "100 kΩ · ½ W",
        "role": "V1A (bright) plate load"
      },
      {
        "ref": "RL2",
        "part": "Carbon comp resistor",
        "value": "100 kΩ · ½ W",
        "role": "V1B (normal) plate load"
      },
      {
        "ref": "RK1",
        "part": "Carbon comp resistor",
        "value": "820 Ω · ½ W",
        "role": "Shared input-stage cathode bias"
      },
      {
        "ref": "C1",
        "part": "Electrolytic capacitor",
        "value": "250 µF · 6 V",
        "role": "Shared input-stage cathode bypass"
      },
      {
        "ref": "CC1",
        "part": "Coupling capacitor",
        "value": "0.02 µF · 600 V",
        "role": "V1A plate → Bright volume control, hot lug"
      },
      {
        "ref": "CC2",
        "part": "Coupling capacitor",
        "value": "0.02 µF · 600 V",
        "role": "V1B plate → Normal volume control, hot lug"
      },
      {
        "ref": "VR1",
        "part": "Potentiometer (taper not marked on the drawing)",
        "value": "1 MΩ",
        "role": "Bright-channel volume"
      },
      {
        "ref": "CBR",
        "part": "Mica capacitor",
        "value": "100 pF",
        "role": "Bright cap across VR1, hot lug to wiper (printed .0001; the layout page letters 100 MMF inside the pot)"
      },
      {
        "ref": "VR2",
        "part": "Potentiometer (taper not marked on the drawing)",
        "value": "1 MΩ",
        "role": "Normal-channel volume"
      },
      {
        "ref": "RM1",
        "part": "Carbon comp resistor",
        "value": "270 kΩ · ½ W",
        "role": "Bright-channel mixer, VR1 wiper → the gain stage's grid. The layout page letters this one 250 K; the schematic prints 270K for both mixers"
      },
      {
        "ref": "RM2",
        "part": "Carbon comp resistor",
        "value": "270 kΩ · ½ W",
        "role": "Normal-channel mixer, VR2 wiper → the gain stage's grid"
      },
      {
        "ref": "RL3",
        "part": "Carbon comp resistor",
        "value": "100 kΩ · ½ W",
        "role": "V2A (gain stage) plate load, from the +275 V rail; the layout mounts it on the socket, pin 6 to pin 1"
      },
      {
        "ref": "RK2",
        "part": "Carbon comp resistor",
        "value": "1.5 kΩ · ½ W",
        "role": "V2A cathode bias"
      },
      {
        "ref": "C2",
        "part": "Electrolytic capacitor",
        "value": "25 µF · 25 V",
        "role": "V2A cathode bypass"
      },
      {
        "ref": "RKCF",
        "part": "Carbon comp resistor",
        "value": "100 kΩ · ½ W",
        "role": "V2B cathode-follower load, cathode → ground"
      },
      {
        "ref": "RFB",
        "part": "Carbon comp resistor",
        "value": "10 MΩ · ½ W",
        "role": "Feedback from the tone network's first node back to V2A's grid"
      },
      {
        "ref": "C3",
        "part": "Film capacitor",
        "value": "0.1 µF · 200 V",
        "role": "Tone network — follower cathode → the bass branch's first node"
      },
      {
        "ref": "RBL",
        "part": "Carbon comp resistor",
        "value": "220 kΩ · ½ W",
        "role": "Tone network — the bass branch's first node → ground"
      },
      {
        "ref": "RTS",
        "part": "Carbon comp resistor",
        "value": "220 kΩ · ½ W",
        "role": "Tone network — the bass branch's first node → the Bass control's wiper"
      },
      {
        "ref": "VR4",
        "part": "Potentiometer (taper not marked on the drawing)",
        "value": "1 MΩ",
        "role": "Bass — wiper on the bass branch; one end lug to ground, the other through CBS to ground"
      },
      {
        "ref": "CBS",
        "part": "Film capacitor",
        "value": "0.005 µF · 600 V",
        "role": "Tone network — the Bass control's far end lug → ground (printed .005; the layout letters .005 MFD 600 VOLTS at the pot)"
      },
      {
        "ref": "RTO",
        "part": "Carbon comp resistor",
        "value": "220 kΩ · ½ W",
        "role": "Tone network — the Bass control's wiper → the Treble control's wiper, which is the driver's grid; strung pot to pot on the layout page"
      },
      {
        "ref": "C4",
        "part": "Mica capacitor",
        "value": "250 pF",
        "role": "Tone network — follower cathode → one end of the Treble control (printed .00025; the layout letters 250 MMF)"
      },
      {
        "ref": "VR3",
        "part": "Potentiometer (taper not marked on the drawing)",
        "value": "1 MΩ",
        "role": "Treble — one end fed by C4, the other through C7 to ground, the wiper driving the driver's grid"
      },
      {
        "ref": "C7",
        "part": "Film capacitor",
        "value": "0.01 µF · 400 V",
        "role": "Tone network — the Treble control's far end → ground (printed .01-400; the layout page letters .01 MFD 600 V)"
      },
      {
        "ref": "C8",
        "part": "Mica capacitor",
        "value": "47 pF",
        "role": "Across the Treble control, wiper to the lug C4 feeds. Lettered 47 MMF on the layout page, at the pot; the schematic page does not draw it"
      },
      {
        "ref": "RNF",
        "part": "Carbon comp resistor",
        "value": "20 kΩ · ½ W",
        "role": "Negative feedback, speaker line → the driver's cathode"
      },
      {
        "ref": "VR5",
        "part": "Potentiometer (taper not marked on the drawing)",
        "value": "5 kΩ",
        "role": "Presence — one end on the driver's cathode, the wiper through CPR to ground; the far end is open on the schematic and strapped to the wiper on the layout"
      },
      {
        "ref": "CPR",
        "part": "Film capacitor",
        "value": "0.1 µF · 200 V",
        "role": "Presence wiper → ground"
      },
      {
        "ref": "RLD",
        "part": "Carbon comp resistor",
        "value": "100 kΩ · ½ W",
        "role": "V3A (driver) plate load, from the +335 V rail"
      },
      {
        "ref": "RK3",
        "part": "Carbon comp resistor",
        "value": "1.5 kΩ · ½ W",
        "role": "V3A (driver) cathode bias"
      },
      {
        "ref": "CC3",
        "part": "Coupling capacitor",
        "value": "0.02 µF · 600 V",
        "role": "Driver plate → cathodyne grid"
      },
      {
        "ref": "RLA",
        "part": "Carbon comp resistor",
        "value": "56 kΩ · ½ W",
        "role": "V3B (cathodyne) plate load, from the +335 V rail"
      },
      {
        "ref": "RKA",
        "part": "Carbon comp resistor",
        "value": "1.5 kΩ · ½ W",
        "role": "Cathodyne cathode, upper leg: cathode pin → the junction the grid leak returns to"
      },
      {
        "ref": "RKB",
        "part": "Carbon comp resistor",
        "value": "56 kΩ · ½ W",
        "role": "Cathodyne cathode, lower leg: junction → ground"
      },
      {
        "ref": "RGPI",
        "part": "Carbon comp resistor",
        "value": "1 MΩ · ½ W",
        "role": "Cathodyne grid leak, returned to the 1.5 kΩ/56 kΩ junction"
      },
      {
        "ref": "C5",
        "part": "Coupling capacitor",
        "value": "0.1 µF · 400 V",
        "role": "Cathodyne plate → V4's grid feed"
      },
      {
        "ref": "C6",
        "part": "Coupling capacitor",
        "value": "0.1 µF · 200 V",
        "role": "Cathodyne cathode → V5's grid feed"
      },
      {
        "ref": "RGL1",
        "part": "Carbon comp resistor",
        "value": "220 kΩ · ½ W",
        "role": "V4 grid leak from the bias supply, landing where C5 meets R5s"
      },
      {
        "ref": "RGL2",
        "part": "Carbon comp resistor",
        "value": "220 kΩ · ½ W",
        "role": "V5 grid leak from the bias supply, landing where C6 meets R6s"
      },
      {
        "ref": "R5s",
        "part": "Carbon comp resistor",
        "value": "1.5 kΩ · ½ W",
        "role": "V4 grid stopper, mounted on the socket from pin 6 to the grid at pin 5"
      },
      {
        "ref": "R6s",
        "part": "Carbon comp resistor",
        "value": "1.5 kΩ · ½ W",
        "role": "V5 grid stopper, mounted on the socket from pin 6 to the grid at pin 5"
      },
      {
        "ref": "C9",
        "part": "Electrolytic capacitor",
        "value": "16 µF · 450 V",
        "role": "First filter, +420 V, after the standby switch"
      },
      {
        "ref": "L1",
        "part": "Filter choke",
        "value": "no number printed",
        "role": "+420 V → +410 V; the OT centre tap and both screens sit after it"
      },
      {
        "ref": "C10",
        "part": "Electrolytic capacitor",
        "value": "16 µF · 450 V",
        "role": "Filter, +410 V (first of two cans on this node)"
      },
      {
        "ref": "C11",
        "part": "Electrolytic capacitor",
        "value": "16 µF · 450 V",
        "role": "Filter, +410 V (second of two cans on this node)"
      },
      {
        "ref": "RD1",
        "part": "Power resistor",
        "value": "10 kΩ",
        "role": "Rail dropper, +410 V → +335 V"
      },
      {
        "ref": "C12",
        "part": "Electrolytic capacitor",
        "value": "16 µF · 450 V",
        "role": "Filter, +335 V (driver and cathodyne)"
      },
      {
        "ref": "RD2",
        "part": "Power resistor",
        "value": "10 kΩ",
        "role": "Rail dropper, +335 V → +275 V"
      },
      {
        "ref": "C13",
        "part": "Electrolytic capacitor",
        "value": "8 µF · 450 V",
        "role": "Filter, +275 V (input stage, gain stage, follower)"
      },
      {
        "ref": "RB1",
        "part": "Carbon comp resistor",
        "value": "3.3 kΩ · ½ W",
        "role": "Bias supply series resistor, the HT winding's bias tap → the rectifier (changed from a higher value between the 5E6 and 5E6-A revisions — see the sources on this page)"
      },
      {
        "ref": "D1",
        "part": "Rectifier (bias)",
        "value": "selenium (silicon diode in modern builds)",
        "role": "Bias supply rectifier, + end toward RB1 and − end on the −42 V node"
      },
      {
        "ref": "C14",
        "part": "Electrolytic capacitor",
        "value": "100 µF · 25 V",
        "role": "Bias supply filter, −42 V node → ground"
      },
      {
        "ref": "RB2",
        "part": "Carbon comp resistor",
        "value": "56 kΩ · ½ W",
        "role": "Bias supply bleeder, −42 V node → ground"
      },
      {
        "ref": "V1",
        "part": "Preamp tube",
        "value": "12AY7",
        "role": "Two-channel input: V1A bright, V1B normal"
      },
      {
        "ref": "V2",
        "part": "Preamp tube",
        "value": "12AY7",
        "role": "Gain stage (V2A) direct-coupled to a cathode follower (V2B)"
      },
      {
        "ref": "V3",
        "part": "Preamp tube",
        "value": "12AX7",
        "role": "Driver (V3A) feeding a split-load cathodyne phase inverter (V3B)"
      },
      {
        "ref": "V4",
        "part": "Power tube",
        "value": "6L6G",
        "role": "Push-pull output (upper); simulated on the 5881 family model"
      },
      {
        "ref": "V5",
        "part": "Power tube",
        "value": "6L6G",
        "role": "Push-pull output (lower); simulated on the 5881 family model"
      },
      {
        "ref": "V6",
        "part": "Rectifier tube",
        "value": "5U4GA",
        "role": "Rectifier, tube 1 of 2 (parallel full-wave, not DC-modelled)"
      },
      {
        "ref": "V7",
        "part": "Rectifier tube",
        "value": "5U4GA",
        "role": "Rectifier, tube 2 of 2 (parallel full-wave, not DC-modelled)"
      },
      {
        "ref": "T1",
        "part": "Power transformer",
        "value": "no number printed",
        "role": "HT winding with centre tap and bias tap, 5 V rectifier filament, 6.3 V heaters"
      },
      {
        "ref": "T3",
        "part": "Output transformer",
        "value": "no number printed",
        "role": "Push-pull output into four 10-inch speakers"
      },
      {
        "ref": "—",
        "part": "Film capacitor",
        "value": "0.05 µF · 600 V",
        "role": "Line bypass through the ground switch to chassis"
      },
      {
        "ref": "—",
        "part": "Film capacitor",
        "value": "0.05 µF · 600 V",
        "role": "HT bypass, rectifier output → ground, ahead of the standby switch"
      },
      {
        "ref": "—",
        "part": "Fuse",
        "value": "3 A",
        "role": "AC line fuse"
      },
      {
        "ref": "—",
        "part": "Switch",
        "value": "SPST",
        "role": "AC switch"
      },
      {
        "ref": "—",
        "part": "Switch",
        "value": "SPDT",
        "role": "Ground switch, selecting which mains lead the 0.05 µF bypass reaches"
      },
      {
        "ref": "—",
        "part": "Switch",
        "value": "SPST",
        "role": "Standby switch, rectifier output → the +420 V can"
      },
      {
        "ref": "—",
        "part": "Lamp",
        "value": "Pilot lamp",
        "role": "Panel pilot light, off the 6.3 V heater winding"
      }
    ]
  },
  "publishedVoltages": {
    "source": "Fender 5E6-A (A-EE) drawing, printed voltages: rails +420 (first filter, after the standby switch), +410 (after the choke: screens and OT centre tap), +335, +275; bias -42; 6L6G plates +405; 12AY7 input plates +130, shared cathode +2; 12AY7 gain stage plate +130, cathode +2; cathode follower's cathode +130; 12AX7 driver plate +200, cathode +1.7; cathodyne plate +260, cathode +72, and on the layout page +70 at the cathode resistors' junction.",
    "nodes": {
      "BP1": {
        "chart": 420,
        "tol_pct": 8,
        "note": "first filter can, after the standby switch; the netlist drives this node"
      },
      "BP2": {
        "chart": 410,
        "tol_pct": 8,
        "note": "after the choke: both screens and the OT centre tap. The choke's resistance is estimated from this very drop, so agreement here is by construction. The plates read +405 V on the drawing, 5 V under the tap across the primary the netlist does not model"
      },
      "BP3": {
        "chart": 335,
        "tol_pct": 8,
        "note": "driver and cathodyne supply, after the first 10 kΩ dropper"
      },
      "BP4": {
        "chart": 275,
        "tol_pct": 8,
        "note": "preamp supply after the second 10 kΩ dropper: both input plate loads, the gain stage's plate load and the cathode follower's plate"
      },
      "PAY1": {
        "chart": 130,
        "tol_pct": 20,
        "note": "input stage, bright-channel plate (12AY7)"
      },
      "PAY2": {
        "chart": 130,
        "tol_pct": 20,
        "note": "input stage, normal-channel plate (12AY7)"
      },
      "KAY": {
        "chart": 2,
        "tol_pct": 20,
        "note": "shared input-stage cathode, 820 Ω"
      },
      "P2A": {
        "chart": 130,
        "tol_pct": 20,
        "note": "gain stage plate (12AY7), 100 kΩ load; also the cathode follower's grid, direct-coupled"
      },
      "K2A": {
        "chart": 2,
        "tol_pct": 20,
        "note": "gain stage cathode, 1.5 kΩ with 25 µF"
      },
      "KCF": {
        "chart": 130,
        "tol_pct": 20,
        "note": "cathode follower's cathode, 100 kΩ to ground; the tone network's feed"
      },
      "PDR": {
        "chart": 200,
        "tol_pct": 20,
        "note": "driver plate (12AX7), 100 kΩ load"
      },
      "KDR": {
        "chart": 1.7,
        "tol_pct": 20,
        "note": "driver cathode: 1.5 kΩ to ground, and the 20 kΩ feedback resistor to the speaker line in parallel with it at DC"
      },
      "PPI": {
        "chart": 260,
        "tol_pct": 20,
        "note": "cathodyne plate, 56 kΩ load"
      },
      "KPI": {
        "chart": 72,
        "tol_pct": 20,
        "note": "cathodyne cathode pin, above the 1.5 kΩ + 56 kΩ legs"
      },
      "JPI": {
        "chart": 70,
        "tol_pct": 20,
        "note": "1.5 kΩ/56 kΩ junction, where the cathodyne's 1 MΩ grid leak returns. The schematic page letters no figure here; the layout page prints +70 V at this eyelet"
      },
      "G51": {
        "chart": -42,
        "tol_pct": 8,
        "note": "upper 6L6G grid: 220 kΩ from the bias supply, then the 1.5 kΩ stopper"
      },
      "G52": {
        "chart": -42,
        "tol_pct": 8,
        "note": "lower 6L6G grid, the same feed"
      }
    }
  },
  "operatingPoint": [
    {
      "node": "BP1",
      "chart": 420,
      "sim": 420,
      "disputed": false,
      "dev_pct": 0,
      "tol_pct": 8,
      "gated": true,
      "within": true,
      "note": "first filter can, after the standby switch; the netlist drives this node",
      "dispute_note": ""
    },
    {
      "node": "BP2",
      "chart": 410,
      "sim": 409.829,
      "disputed": false,
      "dev_pct": 0.04170731707316885,
      "tol_pct": 8,
      "gated": true,
      "within": true,
      "note": "after the choke: both screens and the OT centre tap. The choke's resistance is estimated from this very drop, so agreement here is by construction. The plates read +405 V on the drawing, 5 V under the tap across the primary the netlist does not model",
      "dispute_note": ""
    },
    {
      "node": "BP3",
      "chart": 335,
      "sim": 332.287,
      "disputed": false,
      "dev_pct": 0.8098507462686634,
      "tol_pct": 8,
      "gated": true,
      "within": true,
      "note": "driver and cathodyne supply, after the first 10 kΩ dropper",
      "dispute_note": ""
    },
    {
      "node": "BP4",
      "chart": 275,
      "sim": 277.442,
      "disputed": false,
      "dev_pct": 0.8880000000000027,
      "tol_pct": 8,
      "gated": true,
      "within": true,
      "note": "preamp supply after the second 10 kΩ dropper: both input plate loads, the gain stage's plate load and the cathode follower's plate",
      "dispute_note": ""
    },
    {
      "node": "PAY1",
      "chart": 130,
      "sim": 142.962,
      "disputed": false,
      "dev_pct": 9.970769230769221,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "input stage, bright-channel plate (12AY7)",
      "dispute_note": ""
    },
    {
      "node": "PAY2",
      "chart": 130,
      "sim": 142.962,
      "disputed": false,
      "dev_pct": 9.970769230769221,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "input stage, normal-channel plate (12AY7)",
      "dispute_note": ""
    },
    {
      "node": "KAY",
      "chart": 2,
      "sim": 2.205,
      "disputed": false,
      "dev_pct": 10.250000000000004,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "shared input-stage cathode, 820 Ω",
      "dispute_note": ""
    },
    {
      "node": "P2A",
      "chart": 130,
      "sim": 138.986,
      "disputed": false,
      "dev_pct": 6.912307692307684,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "gain stage plate (12AY7), 100 kΩ load; also the cathode follower's grid, direct-coupled",
      "dispute_note": ""
    },
    {
      "node": "K2A",
      "chart": 2,
      "sim": 2.077,
      "disputed": false,
      "dev_pct": 3.849999999999998,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "gain stage cathode, 1.5 kΩ with 25 µF",
      "dispute_note": ""
    },
    {
      "node": "KCF",
      "chart": 130,
      "sim": 141.032,
      "disputed": false,
      "dev_pct": 8.486153846153854,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "cathode follower's cathode, 100 kΩ to ground; the tone network's feed",
      "dispute_note": ""
    },
    {
      "node": "PDR",
      "chart": 200,
      "sim": 214.752,
      "disputed": false,
      "dev_pct": 7.376000000000005,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "driver plate (12AX7), 100 kΩ load",
      "dispute_note": ""
    },
    {
      "node": "KDR",
      "chart": 1.7,
      "sim": 1.64,
      "disputed": false,
      "dev_pct": 3.529411764705886,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "driver cathode: 1.5 kΩ to ground, and the 20 kΩ feedback resistor to the speaker line in parallel with it at DC",
      "dispute_note": ""
    },
    {
      "node": "PPI",
      "chart": 260,
      "sim": 271.003,
      "disputed": false,
      "dev_pct": 4.231923076923072,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "cathodyne plate, 56 kΩ load",
      "dispute_note": ""
    },
    {
      "node": "KPI",
      "chart": 72,
      "sim": 62.926,
      "disputed": false,
      "dev_pct": 12.602777777777774,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "cathodyne cathode pin, above the 1.5 kΩ + 56 kΩ legs",
      "dispute_note": ""
    },
    {
      "node": "JPI",
      "chart": 70,
      "sim": 61.284,
      "disputed": false,
      "dev_pct": 12.451428571428574,
      "tol_pct": 20,
      "gated": true,
      "within": true,
      "note": "1.5 kΩ/56 kΩ junction, where the cathodyne's 1 MΩ grid leak returns. The schematic page letters no figure here; the layout page prints +70 V at this eyelet",
      "dispute_note": ""
    },
    {
      "node": "G51",
      "chart": -42,
      "sim": -42,
      "disputed": false,
      "dev_pct": 0,
      "tol_pct": 8,
      "gated": true,
      "within": true,
      "note": "upper 6L6G grid: 220 kΩ from the bias supply, then the 1.5 kΩ stopper",
      "dispute_note": ""
    },
    {
      "node": "G52",
      "chart": -42,
      "sim": -42,
      "disputed": false,
      "dev_pct": 0,
      "tol_pct": 8,
      "gated": true,
      "within": true,
      "note": "lower 6L6G grid, the same feed",
      "dispute_note": ""
    }
  ],
  "checks": [
    {
      "id": "dc",
      "title": "DC operating point",
      "status": "Within target",
      "summary": "17 reference nodes are within tolerance. The circuit remains a draft awaiting maintainer review.",
      "details": [
        "This compares simulated DC conditions with the cited reference. It does not test sound, physical construction or every part of the circuit."
      ],
      "tone": "checked"
    },
    {
      "id": "schematic",
      "title": "Schematic against DC model",
      "status": "Checked",
      "summary": "Connectivity of modelled components is checked on every change.",
      "details": [
        "Parts outside the DC model need separate checks and source review."
      ],
      "tone": "checked"
    },
    {
      "id": "board",
      "title": "Board against DC model",
      "status": "Checked",
      "summary": "Connectivity of modelled components is checked on every change.",
      "details": [
        "This does not establish heater wiring or physical spacing."
      ],
      "tone": "checked"
    },
    {
      "id": "drawings",
      "title": "Schematic against board",
      "status": "No open findings",
      "summary": "No disagreement is listed in the published comparison.",
      "details": [
        "A finding identifies a difference or a coverage gap. The factory source must decide which drawing, if either, needs correction.",
        "0 sheet-only parts are explicitly excluded. Heaters and the pilot lamp are checked separately."
      ],
      "tone": "checked"
    },
    {
      "id": "heaters",
      "title": "Heater and filament wiring",
      "status": "Not established",
      "summary": "The drawn supply-leg connections have not been established by this check.",
      "details": [
        "Supply-leg grouping still needs confirmation at V1, V2, V3.",
        "V1: pins [4, 5] are one leg at 6.3 V and opposite legs at 12.6 V"
      ],
      "tone": "attention"
    },
    {
      "id": "polarity",
      "title": "Capacitor polarity",
      "status": "Checked",
      "summary": "8 capacitor markings agree with the model's voltage ordering.",
      "details": [
        "This check uses DC voltage ordering; source review establishes markings the model cannot decide."
      ],
      "tone": "checked"
    }
  ],
  "corrections": [],
  "sourceDirectory": "https://github.com/TheAnalogMaker/circuit-codex/tree/ebddc3fd2cf887dca010bbe60487d7391ea6c052/amps/5e6a"
}