Plankton Electronics is a Barcelona-based maker of analog synthesizers, Eurorack modules, and effects, founded by Àlex Ballester. The company grew out of a DIY background — Ballester spent years working as a sound engineer and building his own synths, tube hardware, and stomp boxes — and that ethos carries through to the brand's open approach of publishing schematics and design details for many of its circuits.

The catalog spans both standalone and Eurorack formats. The Ants! is a semi-modular analog desktop synthesizer with more than 50 patch points and 19 knobs, originally launched via Kickstarter and also available as Eurorack modules. Other releases include The Jellyfish delay, the SPICE semi-modular saturator, the SPICE VCF filter, the ENVF envelope follower, the NUTONE dual-channel distortion, the ZAPS analog voice module, and utility accessories like the Ninja Star splitter hubs.

The brand sits in the boutique end of the modular and small-format synth market, with a focus on hands-on, patch-driven analog signal paths rather than menu-based digital instruments. Its products are sold direct through the Plankton Electronics web shop and through specialist synth retailers in Europe and North America.

Plankton Electronics has 2 products cataloged on Equipboard, including Modular Synthesizers.