1930s: The first effect came built into Rickenbacker’s Vibrola Spanish Guitar. It used a motorized pulley system to modify pitch, creating the first floating tremolo bridge.

1940s: Guitarists DIY-ed early effects, though most were only possible in the recording studio.

• Les Paul manipulated reel-to-reel tape to add echo effects.
• Duane Eddy created a studio reverb/echo chamber using a 500-gallon water tank outfitted with a microphone and speaker.

By the late ’40s, amp makers started including gain and reverb, utilized by guitarists like Roy Orbison and Chet Atkins to make a “Slapback” effect.

• First tremolo amp: Gibson GA-50T and Premier ’66’ (1948)
• First spring reverb amp: EchoSonic (1950)

1946: Release of first commercial stand-alone guitar effect (Trem Trol 800 Tremolo).

• The guitar’s signal passed through a glass jar of electrolytic fluid. The pedal’s motor would shake the jar, making the signal fluctuate.
• Used famously by: Bo Diddley (“Diddley Daddy”, “Pretty Thing”), Muddy Waters (“Flood”)

1950s: Guitarists discover distortion (for the most part completely by accident).

• ’50s power chord master Pat Hare achieved distortion by turning the volume knob “all the way to the right until the speaker was screaming”.
• Link Wray reportedly stabbed a hole in his amp’s speaker for the distortion on “Rumble”.
• Willie Kizert (Ike Turner and the Rhythm Kings) found the first fuzz effect after dropping his Fender Bassman amp on a rainy street, blowing a tube.

1956: First intentional guitar distortion attributed to a 1956 recording from Johnny Burnette’s Rock ‘n Roll Trio.

• Marshall Amplification soon followed with the Marshall 1963, the first amp to intentionally produce distortion.

In the late ’50s and early ’60s, stand-alone effects gained popularity. Powered by vacuum tubes, they were bulky, expensive, and fragile, limiting their use

• Gibson GAV-I: first popular stand-alone vibrato
• Fend Reverb Box: first popular stand-alone reverb (released 1961)
• Watkins Copicat: first portable tape echo effect (released in 1958, popularized by The Shadows)

1960s: The first transistor-powered pedals hit the market. Cheaper, lighter, and more stable, these pedals made effects available to more players

• Maestro Fuzz Tone, 1962: marketed by Gibson, made famous by Rolling Stones (“Satisfaction”)
• The Clyde McCoy, 1967: First wah-wah pedal, made by Warwick Electronics
• Octavio, 1967: First octave effect, Named by Jimi Hendrix and made by Jim Morris of Kelsey-Morris Sound
• Uni-Vibe, 1968: marketed by Univox and based off the Leslie rotating speaker, made famous by Jimi Hendrix

1970s: Effects pedals skyrocketed in popularity. The options expanded and solidified into the basic categories you’ll still find today:

Signal alterations: Narrows or expands the signal’s tone or level

• Boost: raises signal level
• Compression: narrows tone range
• Volume: Pedal volume operation for swells and fades
• Noise gate: Hides sound going into amp when guitar is silent

Distortion: Mimics the sounds of damaged or overdriven vacuum tubes

• Overdrive: sound of tube amps pushed to their limit
• Fuzz: Replicates buzzy tone of a busted vacuum tube
• Digital distortion: alters waveform and boosts levels

Modulation: Changes the pitch or frequency of the signal

• Vibrato: Quick, subtle pitch changes (can be produced manually using whammy bars)
• Tremolo: Quick, subtle dynamic changes
• Octave: Signal output up or down an octave
• Phaser: Signal is split and played back at different wavelengths
• Flange: More sweeping form of phaser
• Ring modulator: Signal is split and internal oscillator makes math-based alterations

Time-based effects: Duplicates original signal, often with modifications

• Echo: Adds echo to signal
• Reverb: Multiple echoes with different decay rates emulates sense of space
• Chorus: Signal duplicated and slightly detuned to sound like multiple players
• Delay: Signal played back after short pause
• Reverse delay: Signal reversed then played back
• Loop: Full phrases recorded and layered

Filter Effects: Alters select frequencies

• Equalizer (EQ): Boost or low specific frequencies or ranges
• Wah-Wah: Filter or compress select frequencies to create crying sound
• Envelope filter: Folds sound back on itself
• Talk box: Links guitar sound to vocals