AJH Synth is a Eurorack modular synthesizer manufacturer based in Bournemouth, England, founded by Allan Hall. The company is best known for its MiniMod series, a range of modules inspired by the circuitry of the Minimoog Model D, including the MiniMod Transistor Core VCO, MiniMod Ladder Filter, Dual Contour envelope generators, and a self-contained MiniMod Keyz keyboard synthesizer.

Beyond the MiniMod line, the brand produces a variety of other Eurorack modules such as the Sonic XV diode filter (based on the EMS VCS3 filter), the Ring SM ring modulator, the Entropic Doom, the Tap Tempo VC-LFO, and the Wave Swarm. Modules are typically available in both silver and black "Dark Edition" faceplates. AJH Synth has also built custom instruments on commission, including the RadioPhonic synthesizer delivered to composer Hans Zimmer.

AJH Synth has 31 products cataloged on Equipboard, including Modular Synthesizers and Synthesizers. Their gear is featured by 3 artists, with the strongest followings in Electronic, Rock, and Pop. Notable users include Richard Devine, Hélène Vogelsinger, and Hans Zimmer. Most AJH Synth products fall in the mid-tier range — professional-grade without flagship pricing.