Schumann Electronics is a boutique effects pedal builder founded by John Schumann, a self-taught electronics designer who relocated from western Massachusetts to New York City in 1996 to manufacture his own line of guitar pedals. The company's pedals were originally built in small numbers and sold through Main Drag Music in Williamsburg, Brooklyn, where they developed a cult following among experimental and noise-oriented players.

The brand is best known for the PLL (Phase Locked Loop), an analog harmonizer that converts an instrument's input into a square wave and adds programmable intervals to create chord-like polyphony, glitchy octaves, synth-style drones, and chaotic pitch artifacts. The PLL is often available with companion add-ons such as a Drone generator and a momentary activation footswitch, and has inspired a small subgenre of clones and tribute pedals from other boutique builders. Other Schumann designs include the Two Face Fuzz, the Lion and Lion X fuzz/distortion pedals, and standalone Drone units.

Schumann pedals are hand-built in low serial-numbered runs, which has made them sought after on the secondary market. The PLL in particular has been associated with adventurous studio acts and harder-edged guitarists who use it for textural, non-pitched effects rather than as a traditional harmonizer.

Schumann has 2 products cataloged on Equipboard, including Guitar Synth Pedals and Overdrive Effects Pedals. Their gear is featured by 3 artists, with the strongest followings in Rock. Notable users include Reba Meyers, Justin Pearson, and Corin Tucker.