Orthogonal Devices is a Tokyo-based one-person operation founded by Brian Clarkson, building Eurorack modules since 2012. The brand is best known among modular synthesis enthusiasts for a small, deeply considered product line: the ER-101 Indexed Quad Sequencer, the ER-102 Sequencer Controller (an expander for the ER-101), and the ER-301 Sound Computer.

The ER-101 and ER-102 form a sequencing environment built around long, intricate sequences with variable step durations and gate lengths, arbitrary scales, and snapshot-based recall. The ER-301, released in 2016, takes a different angle — a voltage-controlled, user-programmable digital signal processing platform that lets the patcher build oscillators, samplers, effects, and complex multi-channel processing chains from a library of units. Each module is supported by long-running firmware development and an active user forum and documentation site.

The brand operates as a niche, boutique maker rather than a mass manufacturer, and its modules have developed a strong reputation in the experimental and generative-music corners of the Eurorack community for their depth and unconventional design philosophy.

Orthogonal Devices has 2 products cataloged on Equipboard, including Modular Synthesizers. Their gear is featured by 4 artists, with the strongest followings in Electronic and Pop. Notable users include Richard Devine, Caterina Barbieri, and Andrew Huang.