Modulation pedals add movement, depth, and texture to your guitar tone. These guides cover every major type, from chorus and flanger to phaser, tremolo, and vibrato, with practical advice on how each works, where it fits in your signal chain, and which suits your playing style.
Modulation pedals are the effects that bring your tone to life. Chorus, flanger, phaser, tremolo, and vibrato all work by splitting your signal and altering one copy before blending it back with the original. The differences between them come down to what gets altered: pitch, timing, phase, or volume. Small changes, but they produce everything from subtle shimmer to full psychedelic swirl. Understanding how modulation effects work gives you far more control over the sounds you create.
If you’re new to modulation, start with our complete guide to modulation pedals. It covers all five core types with audio examples, settings advice, and the history behind each effect. If you already use modulation and want to go deeper, our guide to flanger pedals and our article on flanger placement relative to distortion explore specific types and signal chain decisions in detail.
Where modulation sits in your rig matters as much as which pedal you choose. These effects interact closely with your gain pedals and your time-based effects, and placement before or after distortion produces very different results. You’ll find those topics covered across our signal chain and pedal order guides, which pair naturally with the content here.
All modulation pedals use a low-frequency oscillator (LFO) to continuously vary some aspect of your signal, but the aspect they vary is what makes each type sound distinct. Chorus detunes and delays a copy of your signal slightly, creating a shimmering, doubled sound. Flanger uses a very short modulated delay to produce a metallic, jet-like sweep through comb filtering. Phaser runs a copy through all-pass filters that shift its phase, creating a smoother, more subtle movement. Tremolo modulates your volume for a pulsing effect, while vibrato modulates your pitch. These are not interchangeable effects. A phaser will never sound like a chorus, and a flanger will never feel like a tremolo. Choosing the right one starts with knowing what kind of movement you want in your tone.
The standard placement for modulation is after your gain pedals but before delay and reverb. This lets the modulation process an already shaped tone without getting smeared by distortion, while delay and reverb then add space around the modulated signal. That said, running a phaser or Uni-Vibe before gain is a classic psychedelic technique. Jimi Hendrix, Eddie Van Halen, and David Gilmour all placed modulation before or around their gain stages to achieve signature sounds. The “correct” position depends entirely on what you’re after.
Stereo modulation is worth exploring if your rig supports it. Chorus, flanger, and phaser all benefit from stereo output, creating movement that shifts across two amps or two sides of a recording. Our guide to stereo guitar pedals explains how to set this up and which effects benefit most. And if you’re still deciding which modulation type to try first, a chorus pedal is the most versatile starting point. It works across nearly every genre and sits comfortably in almost any signal chain without demanding attention.
The five core types are chorus, flanger, phaser, tremolo, and vibrato. Chorus adds a shimmering, doubled quality by detuning a copy of your signal. Flanger creates a metallic, jet-like sweep. Phaser produces a smooth, swirling movement. Tremolo pulses your volume, and vibrato bends your pitch. Related effects include Uni-Vibe, rotary speaker emulation, and ring modulation. Our complete guide to modulation pedals explains how each type works with audio examples and settings advice.
Place them after gain pedals (overdrive, distortion, fuzz) but before time-based effects (delay, reverb). This keeps the modulation clean and defined rather than smeared by distortion. Some players run phaser or Uni-Vibe before gain for a thicker, more psychedelic texture, which is a valid creative choice. Our pedalboard setup guide covers placement for every effect type with diagrams.
All three split your signal and blend an altered copy back with the original, but they alter the copy differently. Chorus detunes and delays the copy for a wide, shimmering sound. Flanger uses a very short modulated delay to create a metallic sweep through comb filtering. Phaser runs the copy through all-pass filters that shift its phase, producing a smoother, more subtle movement. Our modulation pedals guide breaks down each type in detail.
Tremolo modulates volume, pulsing your signal louder and softer. Vibrato modulates pitch, bending it slightly up and down. They sound and feel quite different despite often being confused. Fender famously labelled them backwards on many vintage amps, which still causes mix-ups today. Our guide to modulation pedals covers both with practical settings for each.