The Lee de Forest Tesla Oscilador is a synthesizer-fuzz-envelope-filter-harmonizer pedal, a single enclosure that sits somewhere between fuzz, synth and pitch effects. At its heart is a square wave oscillator that works in conjunction with your input signal to create a wide range of tones and sounds, which places it closer to Synth Pedals and Octave & Pitch Pedals than to a conventional Fuzz Pedals design1.
What it does
The Freq knob adjusts the frequency of the oscillator, producing octaves, thirds and fifths both above and below the original signal. As it is increased, the pedal moves into gated fuzz territory, so the same control covers everything from interval-based harmonies to choppy, gated fuzz sounds1.
The Tesla is a multi-instrumental device. Pedal of the Day notes it works wonders not just with a guitar, but also beefs up tone on bass and works with keyboard and synth setups, which makes it relevant to players beyond six strings1.
What reviewers said
Pedal of the Day, reviewing the pedal in June 2018, described it as a pedal that resists easy summary1:
"We get pedals coming through the office here from time to time that are so fun and so insane that they’re difficult to write about."
The same review called it "very different and a bold choice for anyone who uses it," adding that "this pedal is not for your average blues-rock gig down at the local bar." In other words, it is aimed at players looking for sounds outside the usual fuzz vocabulary rather than a transparent or traditional drive1.
Videos
Lee De Forest
Lee De Forest
danubilo
Sources (1)
- Lee de Forest Tesla Oscilador Synth Fuzz, Pedal of the Day, 2018-06-27



