EFX Custom Effects is a Brazilian pedal builder based in São Paulo, founded by electrical engineering student Eugenio Vila Gregório. The project began in 2002 as a personal experiment in modifying his guitar's sound and became a formal company in 2009 after friends began requesting clones and modifications of classic effects. The brand operates under the name EFX Pedais in Brazil and sells direct through efxpedais.com.

The catalog covers a wide range of handmade guitar and bass effects, spanning distortion, overdrive and fuzz (including models such as the Bold as Fuzz, Blues Maker, Crunch, Classic AC and Dangerous Drive SS), modulation, octaves and filters, boosters and preamps like the Chandelle Tube Driver, plus utility boxes such as buffers, AB/ABY selectors, cabinet simulators and power supplies. Pedals are built with true-bypass switching and a focus on faithful reproduction of classic circuit voicings.

Alongside its original designs, EFX offers modification and repair services for pedals and amplifiers, a significant part of its business since its early days. The workshop has been covered in Brazilian publications including Guitar Player Brasil and Baixista magazine, and its reputation in the local scene centers on boutique-style builds at more accessible price points than imported equivalents.

EFX Custom Effects has 7 products cataloged on Equipboard, including Overdrive Effects Pedals, Bass Effects Pedals, and Tremolo Effects Pedals.