{"product_id":"audio-merge-ktbk-1b-king-tubby-s-big-knob","title":"Audio Merge KTBK-1B 'King Tubby’s Big Knob'","description":"\u003cp data-start=\"13\" data-end=\"493\"\u003eThe \u003cstrong data-start=\"17\" data-end=\"62\"\u003eAudio Merge  KTBK-1B\u003c\/strong\u003e \u003cmeta charset=\"utf-8\"\u003e\u003cstrong data-start=\"17\" data-end=\"62\"\u003e\"King Tubby’s Big Knob\" \u003c\/strong\u003eis a completely passive, single-channel variable high-pass dub filter and vintage-style equaliser based on the classic Altec 9069B design, featuring a 3rd-order passive filter topology, 10 stepped cut-off frequencies from 70Hz to 7.5kHz, selectable filter modes, adjustable resonance control, 600Ω impedance architecture and a handcrafted multi-tap inductor coil to deliver authentic analogue tone with modern studio adaptability.\u003c\/p\u003e\n\u003ch2 data-start=\"495\" data-end=\"555\"\u003e\u003cstrong data-start=\"498\" data-end=\"555\"\u003eA Classic Dub Filter Reimagined for the Modern Studio\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"557\" data-end=\"922\"\u003eThe King Tubby’s Big Knob KTBK-1B recreates the legendary tone of the Altec 9069B, a vintage passive program equaliser introduced during the 1960s. Audio Merge designed the unit to capture the unmistakable character of the filter that appeared on King Tubby’s MCI mixing console, widely recognised as the producer’s “Big Knob” secret weapon used to shape dub mixes.\u003c\/p\u003e\n\u003cp data-start=\"924\" data-end=\"1326\"\u003eThe original circuit relied on a passive inductor-based T-network filter with toroidally wound inductances, producing an 18dB per octave slope and discrete stepped frequency selection. Audio Merge recreates this behaviour using a custom multi-tap inductor coil, validated with DSP analysis to achieve a highly accurate frequency response and consistent stereo pairing in modern production environments.\u003c\/p\u003e\n\u003cp data-start=\"1328\" data-end=\"1495\"\u003eThe KTBK-1B retains the signature stepped filtering behaviour while adding modern control features that expand its creative potential in contemporary music production.\u003c\/p\u003e\n\u003ch2 data-start=\"1497\" data-end=\"1540\"\u003e\u003cstrong data-start=\"1500\" data-end=\"1540\"\u003eVariable Passive High-Pass Filtering\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"1542\" data-end=\"1784\"\u003eThe filter section provides ten discrete cut-off frequencies ranging from 70Hz to 7.5kHz. Each position introduces a defined step in the high-pass response, which allows engineers to sculpt low-frequency content while preserving musical tone.\u003c\/p\u003e\n\u003cp data-start=\"1786\" data-end=\"2117\"\u003eThe circuit originally targeted dialogue and broadcast processing applications where engineers needed to remove rumble, hum and other low-frequency noise. In modern production the same filtering structure shapes bass content, enhances mix clarity and introduces character when used creatively in dub and electronic music workflows.\u003c\/p\u003e\n\u003cp data-start=\"2119\" data-end=\"2403\"\u003eThe passive architecture requires no power supply and maintains extremely low distortion with a THD rating below 0.01 percent at 1kHz and +17dBu. The design supports a maximum input level of +38dBu and provides a flat frequency response within ±0.5dB from 10Hz to 70kHz when bypassed.\u003c\/p\u003e\n\u003ch2 data-start=\"2405\" data-end=\"2439\"\u003e\u003cstrong data-start=\"2408\" data-end=\"2439\"\u003eThree Distinct Filter Modes\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"2441\" data-end=\"2575\"\u003eThe KTBK-1B expands the original Altec response through a selectable filter mode system that dramatically increases tonal flexibility.\u003c\/p\u003e\n\u003cp data-start=\"2577\" data-end=\"2862\"\u003eThe 600 mode reproduces the original Altec 9069B response and operates with a 6dB insertion loss, preserving the classic behaviour of the vintage circuit. Engineers can use this setting when they require the authentic passive high-pass filtering characteristics of the original design.\u003c\/p\u003e\n\u003cp data-start=\"2864\" data-end=\"3233\"\u003eThe Bell mode recreates the signature sound associated with King Tubby’s dub mixing techniques. This mode generates a resonant high-pass filter response without insertion loss, creating a pronounced resonance peak above the selected cut-off frequency. Engineers often sweep this response to produce phasing-like effects when the filtered signal blends with the dry mix.\u003c\/p\u003e\n\u003cp data-start=\"3235\" data-end=\"3544\"\u003eThe Notch mode introduces a unique Audio Merge design that behaves as a variable notch filter. The attenuation level and Q factor change dynamically depending on the selected cut-off frequency and resonance setting, creating an unconventional filter response that engineers can use for creative tonal shaping.\u003c\/p\u003e\n\u003ch2 data-start=\"3546\" data-end=\"3582\"\u003e\u003cstrong data-start=\"3549\" data-end=\"3582\"\u003eResonance and Damping Control\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"3584\" data-end=\"3761\"\u003eA dedicated resonance level control allows engineers to adjust the damping of the filter response. Six damping levels shape the resonance behaviour in both Bell and Notch modes.\u003c\/p\u003e\n\u003cp data-start=\"3763\" data-end=\"3922\"\u003eThis feature enables precise tuning of the filter’s peak response, allowing subtle tonal enhancement or dramatic resonant sweeps during performance and mixing.\u003c\/p\u003e\n\u003ch2 data-start=\"3924\" data-end=\"3953\"\u003e\u003cstrong data-start=\"3927\" data-end=\"3953\"\u003ePassive Circuit Design\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"3955\" data-end=\"4135\"\u003eThe KTBK-1B uses a completely passive signal path that requires no power consumption. The circuit relies on carefully matched impedance levels to maintain correct filter behaviour.\u003c\/p\u003e\n\u003cp data-start=\"4137\" data-end=\"4468\"\u003eThe design follows the original 600Ω input and output impedance specification used in the Altec circuit, while the mode selector allows compatibility with a wide range of modern studio equipment. This ensures the unit reproduces the classic high-pass response or generates a resonant filter depending on the selected configuration.\u003c\/p\u003e\n\u003ch2 data-start=\"4470\" data-end=\"4519\"\u003e\u003cstrong data-start=\"4473\" data-end=\"4519\"\u003eCustom Inductor and Precision Construction\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"4521\" data-end=\"4754\"\u003eAudio Merge builds every KTBK-1B unit by hand in Barcelona. The engineers designed a custom multi-tap inductor using extensive frequency response and phase analysis to achieve accurate cut-off frequencies across the stepped selector.\u003c\/p\u003e\n\u003cp data-start=\"4756\" data-end=\"4937\"\u003eThe rotary switch offers a smooth but controlled resistance, allowing engineers to perform frequency sweeps during live dubbing or mixing while maintaining precise step positioning.\u003c\/p\u003e\n\u003ch2 data-start=\"4939\" data-end=\"4980\"\u003e\u003cstrong data-start=\"4942\" data-end=\"4980\"\u003eInspired by the Altec 9069B Legacy\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"4982\" data-end=\"5234\"\u003eArthur Davis designed the original Altec 9069B as part of the Altec 9067B programme equaliser system. The device served broadcast, radio and cinema applications where engineers used filtering to simulate distance effects or control low-frequency noise.\u003c\/p\u003e\n\u003cp data-start=\"5236\" data-end=\"5461\"\u003eDub pioneer King Tubby later incorporated the filter into his MCI mixing console, where its stepped switching, audible clicks and phase interactions with the dry signal became part of the distinctive dub production aesthetic.\u003c\/p\u003e\n\u003cp data-start=\"5463\" data-end=\"5589\"\u003eThe KTBK-1B captures this sonic heritage while introducing modern flexibility for contemporary recording and mixing workflows.\u003c\/p\u003e\n\u003ch3 data-start=\"5591\" data-end=\"5655\"\u003e\u003cstrong data-start=\"5595\" data-end=\"5655\"\u003eWhy Choose the Audio Merge King Tubby’s Big Knob KTBK-1B\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cul data-start=\"5657\" data-end=\"6327\"\u003e\n\u003cli data-start=\"5657\" data-end=\"5767\"\u003e\n\u003cp data-start=\"5659\" data-end=\"5767\"\u003eDelivers the authentic sonic character of the legendary Altec 9069B filter used in classic dub productions\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"5768\" data-end=\"5863\"\u003e\n\u003cp data-start=\"5770\" data-end=\"5863\"\u003eProvides powerful tone-shaping capabilities for mixing, sound design and creative filtering\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"5864\" data-end=\"5958\"\u003e\n\u003cp data-start=\"5866\" data-end=\"5958\"\u003eProduces distinctive resonant sweeps that recreate the iconic King Tubby dub mixing effect\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"5959\" data-end=\"6050\"\u003e\n\u003cp data-start=\"5961\" data-end=\"6050\"\u003eIntegrates easily into modern studio setups while maintaining vintage circuit behaviour\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"6051\" data-end=\"6148\"\u003e\n\u003cp data-start=\"6053\" data-end=\"6148\"\u003eOffers highly musical stepped filtering that enhances analogue character in digital workflows\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"6149\" data-end=\"6248\"\u003e\n\u003cp data-start=\"6151\" data-end=\"6248\"\u003eSupports creative performance techniques through smooth stepped switching and resonance control\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"6249\" data-end=\"6327\"\u003e\n\u003cp data-start=\"6251\" data-end=\"6327\"\u003eProvides handcrafted build quality with carefully tuned passive components\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr data-start=\"6329\" data-end=\"6332\"\u003e","brand":"Audio Merge","offers":[{"title":"Default Title","offer_id":57071263220095,"sku":"ITM011250","price":495.83,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0707\/4915\/9716\/files\/audio-merge-ktbk1-kmr4.jpg?v=1772640840","url":"https:\/\/kmraudio.com\/products\/audio-merge-ktbk-1b-king-tubby-s-big-knob","provider":"KMR Audio","version":"1.0","type":"link"}