Skip to main content
Music Radar MusicRadar The No.1 website for musicians
Sign in
  • View Profile
  • Sign out
  • Guitar Amps
  • Plugin Week 25
  • Guitar Pedals
  • Synths
  • Guitars
  • Artist news
  • Keyboards & Pianos
  • Controllers
  • Software & Apps
  • Drums
  • More
    • Recording
    • DJ Gear
    • Acoustic Guitars
    • Bass Guitars
    • Tech
    • Tutorials
    • Reviews
    • Buying Guides
    • About Us
More
  • Plugin Week A-Z
  • You Oughta Know
  • Fake AI band
  • 95k+ free music samples
  • Wrecking Crew
Recommended reading
Pedalboard
Guitar Pedals The ultimate guide to pedal board essentials (and what order to put them in)
Uvi Phasor
Music Production Tutorials How modulation effects work and how to use them
native instruments
Music Production Tutorials "As nuanced as the real thing, but only if you know what you're doing": The ultimate guide to plugin guitars
MXR MB301 Bass Synth: the six-knob pedal is pictured in use against a petrol-blue background.
Bass Guitars “Thunderous sub-octave, expressive envelope, and lush modulation effects with killer tracking and sustain”: MXR unveils the MB301 Bass Synth – instant funk for your pedalboard
Polyend Mess
Guitar Pedals “Not another multi-effect for your dentist": Polyend’s Mess looks like an FX sequencing powerhouse
Soma Laboratory Harvezi Hazze
Guitar Pedals “A genuinely fun take on the classic distortion-slash-fuzz pedal”: Soma Laboratory Harvezi Hazze review
Red Witch Apothecary Series Pedals: these beautifully crafted stompboxes have colour-coded aluminium dials, floral designs and some unique analogue circuits.
Guitars Exquisite stompboxes, built to last a lifetime, meet Red Witch’s new Apothecary Series
  1. Guitars
  2. Guitar Pedals

The ultimate guide to guitar FX: modulation

News
By Total Guitar ( Total Guitar ) published 25 October 2012

Everything you ever needed to know about effects pedals

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.

Modulation Pedals

Modulation Pedals

Can't tell your phasers from your flangers? Want to understand the difference between a rotating speaker effect and a vibrato? Click through to find out everything you need to know about modulation effects...

Page 1 of 5
Page 1 of 5
Phaser

Phaser

PHASER became a classic effect in 70s rock, used by everyone from the Eagles to Van Halen to add a swirling psychedelic edge to electric guitar sounds. To understand how phasers work, let’s remind ourselves of a little basic physics.

In their simplest form, soundwaves have regular peaks and troughs, like waves rolling towards a beach. Now imagine two identical soundwaves aligned so that when the one is peaking, the other is in a trough. These two soundwaves are said to be ‘out of phase’. In the most extreme out-of-phase alignments, they cancel each other out completely, resulting in silence.

Phaser pedals split your guitar’s signal into a dry half and a wet half that passes through multiple filters, knocking the two signals out of alignment. When the filtered (wet) signal is mixed with the dry signal again, phase interference occurs that creates cancelled-out gaps in your overall signal’s frequency range.

These gaps are then moved across the spectrum by a low-frequency oscillator (LFO, controlled by the rate knob). This constant movement morphs your guitar’s tone between bassy and warm, to toppy and brittle in regular cycles, creating the ‘swooshing’ sweep of a phaser effect.

Page 2 of 5
Page 2 of 5
Flanger

Flanger

SONICALLY, flangers sound like the lovechild of chorus and phaser, adding a sinister metallic quality that makes them popular with metal bands such as, erm, Metallica.

As with chorus and phaser, the flanger generates its trademark sound by splitting the signal from your guitar into a dry uneffected half, and a wet signal that has a smidgen of delay. The delay times involved are shorter than in a chorus effect, with a typical duration of just a few milliseconds.

When the dry and delayed signals are blended together again, phase interference between them causes harmonically ordered gaps or ‘notches’ to appear in the frequency spectrum. The position of these notches is then swept up and down by a low-frequency oscillator (LFO, controlled by the rate knob) that alters the delay time of the wet signal – just like a phaser.

This produces the characteristic swirling sound. Flangers differ from phasers because the notches in the flanger signal are equally spaced across the frequency range.

Flangers produce a roiling, churning tone that is distinctively cold. Many flangers feed some of the blended output signal back into the input of the effect to add even more metallic, resonant overtones.

Page 3 of 5
Page 3 of 5
Chorus

Chorus

KNOWN for the watery shimmer they add to electric guitar tone, chorus effects are designed to imitate the shimmer sound of a chorus of singers trying to pitch the same note.

Chorus effects split the signal from your guitar into a ‘dry’ half and a duplicate ‘wet’ signal that has a series of short delays and pitch variations applied to it. This wobbled- up signal is then blended back in with the dry signal. Discrepancies in pitch and timing between the wet and dry signals generates a ‘comb filter’ effect: a series of harmonically ordered notches in the frequency spectrum of your guitar tone that resembles the teeth of a comb.

This filtering effect alters with the varying pitch and delay times of the wet signal, controlled by the rate and depth knobs. Chorus pedals are available in both old-school analogue and modern digital varieties. Analogue versions usually sound a touch warmer than digital choruses, employing old-style ‘bucket-brigade’ delay chips to create shimmer and wobble.

Digital versions tend to be as crisp and clean as the crease in Pat Metheny’s slacks, and many, such as Boss’s popular CE-5 Chorus Ensemble, have highly tweakable features, such as stereo outputs and low- and high-pass filters.

Page 4 of 5
Page 4 of 5
Tremelo and vibrato

Tremelo and vibrato

LET’S get one thing straight: that metal stick that you waggle to bend the pitch of your guitar strings? That’s not a tremolo. It’s a vibrato unit. But vibrato is also the name of a popular guitar effect, and both a picking-hand and fretting-hand playing technique.

Confused? So was Fender when in 1954 it christened the Stratocaster’s vibrato system the ‘Synchronized Tremolo’, and in 1956 when it launched the Vibrolux, an amp with a built-in tremolo circuit billed as offering onboard vibrato.

Although the terms have become interchangeable, they are separate effects and definitely not the same thing. Tremolo is a periodic variation in the volume or amplitude of your guitar’s signal. At its most dramatic, tremolo creates the kind of choppy stutter you can hear in Green Day’s Boulevard Of Broken Dreams and How Soon Is Now? by The Smiths, but more subtle flavours can lend a cool retro flavour to your sound.

Vibrato is a periodic variation in pitch. This can be achieved manually by waggling your whammy bar or moving your fingertip while you fret a note. Vibrato stompboxes tend to simulate the popular sound of a 1960s Leslie rotating speaker cabinet. Both pedals operate in a fairly similar way, with a rate control setting the speed that your volume/pitch throbs at, and depth control adjusting how much of your signal is being effected.

Page 5 of 5
Page 5 of 5
Total Guitar
Total Guitar
Social Links Navigation

Total Guitar is Europe's best-selling guitar magazine.

Every month we feature interviews with the biggest names and hottest new acts in guitar land, plus Guest Lessons from the stars.

Finally, our Rocked & Rated section is the place to go for reviews, round-ups and help setting up your guitars and gear.

Subscribe: http://bit.ly/totalguitar

Stay up to date with the latest gear and tuition. image
Stay up to date with the latest gear and tuition.
Subscribe and save today!
More Info
Read more
Pedalboard
The ultimate guide to pedal board essentials (and what order to put them in)
Uvi Phasor
How modulation effects work and how to use them
native instruments
"As nuanced as the real thing, but only if you know what you're doing": The ultimate guide to plugin guitars
MXR MB301 Bass Synth: the six-knob pedal is pictured in use against a petrol-blue background.
“Thunderous sub-octave, expressive envelope, and lush modulation effects with killer tracking and sustain”: MXR unveils the MB301 Bass Synth – instant funk for your pedalboard
Polyend Mess
“Not another multi-effect for your dentist": Polyend’s Mess looks like an FX sequencing powerhouse
Soma Laboratory Harvezi Hazze
“A genuinely fun take on the classic distortion-slash-fuzz pedal”: Soma Laboratory Harvezi Hazze review
Latest in Guitar Pedals
MXR MB301 Bass Synth: the six-knob pedal is pictured in use against a petrol-blue background.
“Thunderous sub-octave, expressive envelope, and lush modulation effects with killer tracking and sustain”: MXR unveils the MB301 Bass Synth – instant funk for your pedalboard
V863-CA Semi-auto Wah
Vox V863-CA Semi-Auto Wah Pedal review
Crazy Tube Circuits Mirage: the dual reverb features two independent DSP engines each equipped with 16 reverb modes – and there are flexible routing options.
With dual reverb engines, 16 algorithms, Crazy Tube Circuits’ Mirage is one serious reverb pedal
Behringer BM-15M Murf Box: this vintage-style multi-filter pedal has eight filters, selectable patterns and MIDI control
Behringer unveils the BM-15M Murf Box, a $129 animated filtering pedal based on a ‘00s Moog classic
Catalinbread Proto Club Triton Pitch Echo
“The Tritone was universally loved by the crew but the vibes clashed with the palette of the Soft Focus Deluxe”: Catalinbread is selling off its prototype guitar pedals, and the first is a “B-side” pitch echo from its smash-hit shoegaze stompbox
The KHDK Electronics Digital Bath was co-developed with Deftones frontman Chino Moreno, who is pictured here in a white T-shirt and black trousers, performing at Lollapalooza 2024.
KHDK teams up with Chino Moreno for a “melancholic” delay that promises an iconic Deftones tone
Latest in News
Exodus Gary Holt
"It might have been like 12 people there”: Exodus’ Gary Holt pulls zero punches in his new autobiography
Jeff Lynne ELO
"Jeff is devastated": ELO's last ever mega-gig plunged into jeopardy after last-minute cancellation of last night's Manchester show
Deals of the week
MusicRadar deals of the week: It's your last chance to grab a Prime Day deal on gear from Fender, Roland, Casio, Yamaha, Toontrack & more - but you'll have to be quick
Ernie Ball Music Man Pino Palladino StingRay: the bass legend's new signature model is offered fretted or fretless, and in a deep and luxurious 79 Burst finish.
Pino Palladino teams up with EBMM for a signature StingRay inspired by the bass that started it all
Amerie
How Amerie created a ‘00s R&B/funk classic with producer Rich Harrison
Mooer Audio F15i Li Intelligent Amp: this battery-powered take-anywhere guitar amp is packed with amp and effects models, and is an all-in-one practice solution.
Mooer’s F15i Intelligent Amp is a desktop doozie equipped with 55 amps, 69 effects and a touchscreen

MusicRadar is part of Future plc, an international media group and leading digital publisher. Visit our corporate site.

  • About Us
  • Contact Future's experts
  • Terms and conditions
  • Privacy policy
  • Cookies policy
  • Advertise with us
  • Accessibility Statement
  • Careers

© Future Publishing Limited Quay House, The Ambury, Bath BA1 1UA. All rights reserved. England and Wales company registration number 2008885.

Please login or signup to comment

Please wait...