Transistor Sounds Labs is a UK-based maker of Eurorack modules, founded by Nina Richards and Zoë Blade. The company operates under the broader Transistor Sounds umbrella, which also encompasses a record label.

Their flagship product is the Stepper Acid (SA-100), a 16-step Eurorack sequencer module inspired by the Roland TB-303 and designed specifically for live performance. The 32HP module features a dual microcontroller architecture — one dedicated to sequencing and the other to the front panel interface — ensuring tight timing. It stores up to 40 patterns, offers a song mode for chaining sequences, includes variable swing and analogue slide controls, and supports multiple clock sync resolutions. A built-in mini keyboard allows direct pattern programming without menu diving. The Stepper Acid has been adopted by artists including Trent Reznor of Nine Inch Nails and Rick Smith of Underworld.

Nina Richards, the hardware designer behind the Stepper Acid, is also known for composing music for the Philosophy Tube YouTube channel. Zoë Blade contributes as a musician and modular synthesist, creating music for the ContraPoints series.

Transistor Sounds has 1 product cataloged on Equipboard, including Modular Synthesizers.