King Tubby’s Big Knob

Dub Filter is a filter plugin modeled after King Tubby’s iconic Big Knob, a passive high-pass filter with eleven frequency steps from 70Hz to 7.5KHz. This filter defined the sound of the entire “roots” era of Jamaican music. On top of the main stepped Frequency knob and the Impedance (resonance), the filter also offers control over its behavior including Magnetism, Character, Dynamics, and Artefacts controls.

We have also included two modulation sources, LFO and Envelope Follower, to enhance the creative possibilities of the plugin, from rhythmic pulsations to organic filter movements.

Altec 9069B High Pass Filter

Dub Filter is based on the Altec 9069B High Pass Filter as used by King Tubby (and many others) at King Tubbys Studio in Waterhouse, Jamaica. Known infamously as King Tubby’s Big Knob. Altec launched the 9069B filter in the 60s. It was a passive inductor-based T-network filter that provided 18 dB/oct attenuation with 10 positions.

King Tubby is considered a true pioneer of dub music and his experimentation with an MCI console and Altec filter, along with spring reverbs and delays, led to the creation of his signature style.

The Plugin

We meticulously replicated the original filter’s behavior, expanding it with additional controls and modulation. In particular, three controls allow you to modify the filter behavior in depth:

• Magnetism: Controls the non-linear model of the inductance being used in the circuit emulation, affecting the slope and intensity of the generated harmonic content
• Character: Controls the non-linear behavior of the filter, controlling the amount of harmonic content generated
• Dynamics: Controls how smooth is the frequency change made by the non-linear physical model of the inductance; with extreme settings, the model might sound like an envelope filter

Features:

• Stepped High Pass Filter
• LFO modulation with multiple waves
• Envelope Follower modulation
• Non-linearities and Inductance controls
• Resizable Window
• Preset system with randomizer
• Brightness and Contrast Controls