ProCo Rat (RAT)

{
  "schema_version": "capability-outboard-v1",
  "id": "proco-rat",
  "name": "ProCo Rat (RAT)",
  "maker": "Pro Co Sound",
  "clone_of": null,
  "device_class": "distortion",
  "device_class_subtypes": [
    "distortion"
  ],
  "topology": "diode-clipped op-amp distortion (LM308 single op-amp + dual silicon diodes to ground)",
  "topology_note": "Iconic 'Rat' distortion circuit. LM308 op-amp drives a pair of silicon diodes clipping to ground; FILTER is a passive low-pass at the output stage.",
  "channels": 1,
  "linkable": false,
  "params": {
    "distortion": {
      "kind": "transistor",
      "kind_note": "Op-amp + diode-clipper architecture (technically not transistor-only; closest enum match is 'transistor' since the op-amp + diode is the silicon-stage clipping; _verify is also defensible).",
      "drive": "0..100%",
      "drive_note": "DISTORTION knob -- continuous variable from clean-edge to bone-crushing (manual cover + p.2).",
      "tone": true,
      "tone_note": "FILTER knob -- 6 dB/octave passive low-pass (manual p.1 specs). CW = brighter, CCW = darker.",
      "mix_wet_dry": false
    }
  },
  "io": {
    "audio_in": {
      "format": [
        "ts"
      ],
      "balanced": false,
      "impedance_ohms": null,
      "inst_zi": true
    },
    "audio_out": {
      "format": [
        "ts"
      ],
      "balanced": false,
      "impedance_ohms": null
    },
    "sidechain": {
      "send": false,
      "return": false,
      "format": null,
      "per_channel": false
    },
    "stereo_link": false,
    "bypass": "relay",
    "bypass_type": "true_bypass",
    "bypass_note": "'True bypass mode switches both input and output from the signal path to eliminate the loss of power and clarity' (manual p.1).",
    "power_dc": "9V battery OR external +9VDC center-POSITIVE (UNUSUAL -- most pedals are center-negative; the Rat is center-positive per manual p.2 WARNING)",
    "power_dc_note": "Manual p.2 WARNING: 'The power supply must use a negative ground (tip of the plug must be positive). Use of negative supplies can result in damage.' This is opposite to the standard Boss/Dunlop center-negative convention -- use the ProCo RPS-1 or equivalent.",
    "operating_level": [],
    "rack_format": "pedal"
  },
  "meters": [],
  "performance": {
    "bypass_per_channel": false,
    "auto_release": false
  },
  "provenance": {
    "manual_path": "manuals/fx-distortion--proco-rat-manual.pdf",
    "confidence": "high",
    "last_verified": "2026-05-28",
    "manual_pages": [
      1,
      2
    ],
    "verify_via": "SM59 single-seat manual extraction (Opus). P8 pedal-batch tracer #1/13.",
    "verify_note": "Manual-grounded extraction from manuals/fx-distortion--proco-rat-manual.pdf. Front-panel controls captured per the manual's panel descriptions; field provenance is 'high' on what the manual directly states + '_verify' on what it does not. Schema extension fields used by this pedal (params.modulation block; params.distortion.mode_select; io.bypass_type from SM58) are documented in SCHEMA-capability-outboard-v1.md."
  }
}