{
  "schema_version": 1,
  "projection": "envoy-agent-v1",
  "identity": {
    "title": "BK Butler Tube Driver w\/ Bias Knob - 2018",
    "brand": "BK Butler",
    "model": null,
    "mpn": null,
    "gtins": null,
    "handle": "gm-bk-butler-911-tube-driver-reissue-with-bias-knob-bk-butler-tube-driver-f3d9e992",
    "url": "https://envoy-music.myshopify.com/products/gm-bk-butler-911-tube-driver-reissue-with-bias-knob-bk-butler-tube-driver-f3d9e992",
    "catalog_product_id": "reverb_listing:95570057",
    "lane": "pedals",
    "product_object": "tube overdrive pedal"
  },
  "offer": {
    "price": 321.95,
    "currency": "CAD",
    "available": true,
    "condition": "Very Good",
    "price_band": "high",
    "source_verified_at": null
  },
  "specifications": {"category":"Guitar Effects Pedal (Tube Overdrive\/Boost)","groups":[{"id":"identification","label":"Identification","fields":[{"key":"brand","label":"Brand","value":"BK Butler \/ Butler Audio","source":"https:\/\/butleraudio.com\/","confidence":0.95,"display":"BK Butler"},{"key":"model","label":"Model","value":"Tube Driver, 5-Knob Bias version","source":"https:\/\/butleraudio.com\/tdbias.php","confidence":0.9,"display":"Tube Driver - 5 Knob Bias"},{"key":"type","label":"Pedal Type","value":"Analog tube overdrive \/ boost","source":"https:\/\/en.audiofanzine.com\/overdrive-pedal\/bk-butler\/Tube-Driver\/","confidence":0.9,"display":"Analog tube overdrive"},{"key":"build","label":"Build","value":"Hand made in limited production numbers each week by BK Butler","source":"https:\/\/butleraudio.com\/","confidence":0.85,"display":"Hand made"}]},{"id":"tube_circuit","label":"Tube \u0026 Circuit","fields":[{"key":"tube_type","label":"Preamp Tube","value":"12AX7","source":"https:\/\/en.audiofanzine.com\/overdrive-pedal\/bk-butler\/Tube-Driver\/","confidence":0.85,"display":"12AX7 vacuum tube"},{"key":"tube_config","label":"Tube Configuration","value":"Starved-plate","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.8,"display":"Starved-plate"},{"key":"signal_path","label":"Signal Path","value":"Op-amp gain stage into a 12AX7 tube stage, followed by passive two-band EQ","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.8,"display":"Op-amp + 12AX7 + passive EQ"},{"key":"bias_function","label":"Bias Control Function","value":"Adjusts the amount of current applied to the cathode of the tube, allowing the tube's characteristics to be dialed in without swapping tubes","source":"https:\/\/butleraudio.com\/tdbias.php","confidence":0.9,"display":"Adjusts tube cathode current"}]},{"id":"controls","label":"Controls \u0026 Indicators","fields":[{"key":"control_output","label":"Output Level","value":"Rotary control","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.85,"display":"Output Level"},{"key":"control_hi","label":"EQ Hi","value":"High-frequency EQ, passive (flat at minimum, boosts as increased)","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.85,"display":"EQ Hi (passive)"},{"key":"control_lo","label":"EQ Low","value":"Low-frequency EQ, passive (flat at minimum, boosts as increased)","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.85,"display":"EQ Low (passive)"},{"key":"control_drive","label":"Tube Drive","value":"Rotary control","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.85,"display":"Tube Drive"},{"key":"control_bias","label":"Bias","value":"Fifth control on the Bias version, adjusting tube cathode current","source":"https:\/\/butleraudio.com\/tdbias.php","confidence":0.9,"display":"Bias (5th knob)"},{"key":"footswitch","label":"Footswitch","value":"Effect engage\/bypass footswitch","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.85,"display":"Engage\/bypass footswitch"},{"key":"leds","label":"LED Indicators","value":"Two LEDs: green power indicator and red drive\/engaged indicator","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.85,"display":"Green power LED, red engage LED"}]},{"id":"power","label":"Power","fields":[{"key":"power_mains","label":"Power Source","value":"120V AC mains via attached power cord (US standard); no on\/off switch","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.85,"display":"120V AC mains, attached cord"},{"key":"power_export","label":"Export Voltage Option","value":"220-240V, 50-60Hz available at no extra charge","source":"https:\/\/butleraudio.com\/tubedriver.php","confidence":0.85,"display":"220-240V 50\/60Hz option"},{"key":"power_incompat","label":"Power Compatibility","value":"Requires a wall outlet and a three-prong (grounded) mains cord; does not use a Boss-style power plug","source":"https:\/\/en.audiofanzine.com\/overdrive-pedal\/bk-butler\/Tube-Driver\/","confidence":0.8,"display":"Wall outlet, three-prong cord; no Boss-style plug"}]},{"id":"physical","label":"Physical","fields":[{"key":"dimensions","label":"Dimensions","value":"7.25 x 4 x 3.5","unit":"in (L x W x D, including bias mod knob)","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.8,"display":"7.25 in L x 4 in W x 3.5 in D"},{"key":"weight","label":"Weight","value":"2.5","unit":"lb","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.8,"display":"2.5 lb"},{"key":"housing","label":"Housing","value":"Steel enclosure with ventilation slits for tube cooling","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.8,"display":"Steel enclosure"},{"key":"connectors","label":"Connectors","value":"Input and output jacks plus a trailing power cord on the rear panel","source":"http:\/\/www.in2guitar.com\/driver.html","confidence":0.8,"display":"Input \u0026 output jacks, rear power cord"}]},{"id":"warranty","label":"Warranty","fields":[{"key":"warranty","label":"Manufacturer Warranty","value":"3-year warranty (as stated by the manufacturer for new units)","source":"https:\/\/butleraudio.com\/tubedriver.php","confidence":0.8,"display":"3-year warranty (new)"}]}]},
  "connectivity": null,
  "power": null,
  "included_items": null,
  "required_accessories": null,
  "optional_accessories": null,
  "compatibility": null,
  "advisor": {
    "best_for": "Players who want a real 12AX7 tube overdrive\/boost with fine control over feel and gain. The 5-knob Bias version is best for tone-tweakers who like to dial in the tube's response without physically swapping tubes, and for anyone chasing the classic Tube Driver overdrive voicing. The two-band Hi\/Low EQ suits players who want to shape the overdrive to a specific pickup and amp pairing.",
    "who_should_skip": "Anyone building a compact, battery- or 9V-powered pedalboard: this pedal plugs into a 120V AC wall outlet via an attached mains cord and won't run from a pedalboard power supply or daisy chain. It is also large (about 7.25 x 4 x 3.5 in) and heavy (2.5 lb) for a single overdrive, so skip it if board space or weight is tight. Buyers who require true-bypass switching should confirm it with the seller, since it isn't specified.",
    "fit_notes": "This is the 5-knob Bias variant, so expect controls for Output Level, EQ Hi, EQ Low, Tube Drive, and Bias, plus a green power LED and red engage LED. The Bias knob adjusts the tube's cathode current, and small movements make large tonal changes. As a 2018 used unit, condition, tube life, and voltage configuration should be confirmed with the seller. Confirm whether it is wired for 120V (US) or 220-240V before buying for your region, since Butler builds both.",
    "watchouts": "Power is the main gotcha: it draws from 120V AC mains through a fixed three-prong cord and has no on\/off switch, so it can't share a normal pedalboard power supply and needs its own wall outlet (or the 220-240V export build for other regions). Small knob movements produce large tonal changes, so it can be fiddly to set. The manufacturer's 3-year warranty is quoted for new units and may not apply to this used 2018 example, so confirm condition, tube life, and voltage configuration with the seller before buying.",
    "verification_questions": null
  },
  "retrieval": {
    "summary": null,
    "agent_summary": null,
    "intent_terms": null,
    "use_cases": ["live-performance","studio-recording"],
    "skill_level": "intermediate"
  },
  "trust": {
    "has_verified_retail_listing": false,
    "source_count": 0,
    "source_tier_mix": null,
    "evidence_flags": null,
    "spec_provenance": null
  },
  "related": {
    "similar_item_ids": null,
    "comparison_reasons": null
}
}