Coopersonic is an independent effects pedal builder based in Nottingham, England, founded by electronics designer Martin Cooper together with Chris Olley, bassist of the band Six By Seven. Martin originally began building his own pedals because he couldn't afford to buy them, and the partnership with Chris grew out of shared shows and prototypes, eventually leading to a small hand-built product line.

The company is best known for valve-driven and germanium-based dirt pedals, with a catalog that includes the Dual-Valve Distortion (originally called the Valveslapper), the Tubecleaner, the Germaniac germanium fuzz, the Pig Fuzz, and the Dirtbox. Coopersonic also produces utility boxes such as a reamping device and a fader pedal, and offers gear repair services alongside its pedal line.

Each unit is assembled by hand in small numbers in Nottingham using die-cast enclosures and Neutrik jacks, aimed at the boutique end of the market. Coopersonic pedals have been reviewed in outlets including Sound On Sound and MusicRadar, and the Valveslapper has been associated with Arctic Monkeys frontman Alex Turner.

Coopersonic has 5 products cataloged on Equipboard, including Distortion Effects Pedals, Delay Effects Pedals, and Fuzz Effects Pedals. Their gear is featured by 5 artists, with the strongest followings in Rock and Metal. Notable users include Alex Turner, Jamie Cook, and Rabea Massaad.