Audio Surplus is a small-batch effects pedal builder based in Lincoln, United Kingdom, specializing in high-gain fuzz and distortion circuits aimed at players working in doom, sludge, drone, and noise idioms. The operation is boutique in scale, with many releases offered as limited runs that sell out quickly and carry hand-aged metal enclosures and screen-printed graphics.

The catalog leans toward dark, heavy-voiced dirt boxes rather than clean or utility effects. Pedals such as the Burden pair aggressive gain with a pronounced low-pass filter and a 'density' control geared toward gloomy, sub-heavy tones, while the OK Doomer stacks cascading gain stages into a minimalist single-knob interface. Other releases include the Radio Trash overdrive, Lurid Machine, Massenpanik, and Dornenkrone, sold through the brand's Big Cartel storefront.

Audio Surplus Effects has 3 products cataloged on Equipboard, including Fuzz Effects Pedals, Distortion Effects Pedals, and Overdrive Effects Pedals.