MOSFETar

This article describes a fictional musical instrument concept and associated DIY community known as MOSFETar.

MOSFETar is a conceptual electric string instrument that integrates metal–oxide–semiconductor field-effect transistors (MOSFETs) into its core amplification and signal-shaping circuitry. Conceived in the early 2020s by an online collective of instrument builders and electronics hobbyists, the MOSFETar emphasizes hands-on modification, analog warmth, and aggressive harmonic coloration achievable through transistor-based clipping and amplification stages.

Design and construction typically pair a conventional stringed-body and pickup arrangement with a compact, onboard MOSFET amplifier and multi-stage saturation network. Common features include switchable biasing for Class A/B operation, variable gate clipping, and modular preamp boards that permit easy swapping of transistor topologies. Some variants incorporate digital control for preset storage and MIDI integration while retaining analog signal paths for core tone shaping.

The MOSFETar community centers on open hardware schematics, 3D-printable enclosures, and shared firmware for hybrid models. Enthusiasts value the instrument for its tactile control, repairability, and the distinctive compression and harmonic profile MOSFET circuits can impart. Critics note potential reliability and noise concerns compared with commercial amplifiers, and emphasize the need for safe high-voltage handling.

While not a mainstream commercial product, MOSFETar has influenced a subset of boutique builders and experimental musicians interested in the intersection of electronics engineering and instrument design.