If you’re not completely satisfied with the clean, unprocessed sound coming from your guitar and you want to experiment with and modify or color that sound, a great way to tweak it is with effects pedals, also called “stompboxes.” An effects pedal, depending upon its configuration, modifies the sound of your guitar through electrical circuitry or digital modeling via computer chips, either giving it subtle color or dramatic shift. All pedals include knobs on the enclosures that allow you to adjust the intensity, speed, depth and shape of the effect in increments, from nuanced color to ear-splitting crunch.
The range of possibilities for guitar-sound manipulation with effects pedals is staggering―there are literally hundreds of pedals from scores of manufacturers. Here’s a list of some of the most popular types, and their functions.
Distortion: Historically, distorted guitar tone was created within tube amplifiers by overloading signal into the preamp and power amp sections (also called “valve distortion”) to create clipping. Distortion pedals simulate this effect within their own circuitry, creating anything from a warm, crunchy sound to a full-on heavy metal tone.
Overdrive: Unlike a distortion pedal, overdrive pedals will produce clean tones at quieter volumes―but crank up the volume, make your attack more aggressive, and you will get gritty, distorted tone.
Volume, Clean Gain or Boost: Plug into one of these pedals if you need to boost your volume (as much as 20 dB) without altering your guitar tone. If you are playing rhythm guitar and need to increase your volume temporarily to play a solo, this is your pedal.
Wah-Wah: For swishy, rounded sounds that sort of sound like the guitar is wailing, a wah-wah pedal employs a sweeping filter controlled by a spring-loaded treadle, creating quirky frequency boosts as you work the pedal up and down. A famous version of this pedal is marketed by one manufacturer as the “Crybaby,” in an attempt to describe its tone in a name. The late Jimi Hendrix used one of these pedals to great advantage.
Reverb: To simulate the sound of playing in a large, acoustically live space, a reverb pedal creates layers of echoes that gradually fade, adding an extra spatial dimension to otherwise clean, dry guitar tone.
Vibrato: A vibrato pedal creates a tremulous effect, accentuating slight but rapid undulations and variations of the pitch of a long note, not unlike the way a trained soprano can hold a note and slightly modify its pitch as the note is held.
Tremolo: This pedal produces slight but rapid fluctuations in the volume of a note or a chord. Don’t confuse this with a vibrato pedal, which bends pitch slightly.
Chorus: When multiple voices and instruments blend, tones with different pitches still seem to blend together although they are distinct from one another. A chorus pedal recreates the same effect by adding slight vibrato to part of your signal while leaving most of it untouched. This makes the notes you play sound fatter and fuller.
Compression: A compression pedal limits a note’s volume while amplifying its sustain. It controls the strength of your signal to make sure it stays within a specified dynamic range, smoothing the tone.
Equalizer: An equalizer pedal allows you to boost or cut the intensity of certain frequencies of the notes and chords you play. You can add bass or treble or boost your midrange tone to your taste and to suit the acoustic dynamics of a room.
Delay: By adding a second signal from your guitar to your output or recording device, a delay pedal creates an echo of your note or chord. You can control the speed of the delay and the duration of the echo. Delay pedals can be either digital (chip) or analog (old-fashioned circuitry).
Loop: Record a musical phrase or passage on a loop pedal and it will replay your passage so that you can then play a new, live passage over the original recorded one. Some loop pedals enable the recording and replay of multiple, or layered, loops.
Phrase sampler: Like a loop pedal, a phrase sampler will store loops or phrases of even greater length. The more expensive and sophisticated phrase samplers will save multiple phrases or loops, drum and bass, rhythm guitar or practice solos. Some have USB connectivity and can hook up to your computer for uploading so you never lose a loop or phrase.
Flanger: The sound most associated with flangers is that of a streamlined object hurtling through the atmosphere, because a flanger first slows the notes that you are playing and then brings them back up to normal speed.
Phaser: Not too dissimilar to a flanger, a phaser, or phase shifter, creates a rippling, soft whoosh effect by adding elements to your signal that are out of phase, kind of like the wind blowing through your tone in a cyclical fashion.
Rotary: A rotary pedal mimics the Doppler Effect sounds of a vintage Leslie speaker cabinet, by combining its overdrive and phase-shifting abilities, in addition to pitch and volume-modulation characteristics. The speakers in Leslie cabinets rotated to create a swirling, simultaneously coming-and-going sort of sound.
Pitch Bend/Shifting: From a simple octave above the note you’re playing or at intervals in between, a pitch shifter effects pedal will change the pitch of your note or chord. More sophisticated pitch shifters create two or more harmony notes so you can accompany your root note for a fuller sound. Some simulate a chorus effect by providing minute shifts in pitch.
Limiter/Enhancer: These pedals are not unlike equalizers. By limiting or enhancing the strength of certain frequencies of your signal, you can craft and shape your tone. Limiter/enhancer pedals sometimes go by the alias of “exciter” because they emphasize certain midrange and treble frequencies.
Synthesizer: Plug your bass guitar into a synthesizer pedal and you can access four different waveforms (saw-tooth wave, square wave, pulse wave or your own bass wave form) that give you a wide variety of synth tones, each of which can be tweaked in several different ways. Some synth pedals offer a hold function that continues to play the tone as long as you depress the pedal, allowing you to play other musical phrases over the tone the pedal is holding.
Expression pedals: These pedals don’t do anything on their own, says B&H audio expert
Sam Mallery. Typically, they control a single parameter of the effect that another pedal provides, creating a varied, more expessive sound. Some of them come bundled with guitar effects.
When you are shopping for effects pedals, a good feature to look for is true bypass. Your overall signal path is vulnerable to noise and impurities introduced by the circuitry of anything between your guitar and your output device (such as your amplifier/speaker). Pedals without true bypass, or ones with buffered circuitry, will contribute to some signal degradation as your signal passes along the path because the signal is routed directly through the pedal circuitry. Pedals that have true bypass direct your signal around the pedal’s circuitry, or bypass it, when you switch the pedal off, thereby maintaining the integrity and cleanliness of the signal. Your amplified guitar will sound more robust as a result and you won’t be required to crank up your volume as much to compensate for lost signal. The only disadvantage of pedals with true bypass is that sometimes, when you're playing with distorted or high-gain amplifier tones, you might notice switching noise when you switch the pedal off and on.
As the audio world becomes more obsessed with iOS and functionality between electric instruments and the iPad, iPod touch and iPhone, there are now pedals on the market that allow you to use your iOS device as an interface for recording. A pedal such as the DigiTech iStomp Stompbox, with true stereo I/O, is fully configurable. You can download effects apps that will turn them into any kind of effects pedal you require. Need a distortion pedal? Just download the appropriate app and you have a distortion pedal. If you need a jazz chorus pedal, there's a downloadable app for that too, and many others.
A pedal interface such as the IK Multimedia iRig STOMP Stompbox acts more like a switcher in your signal chain, between your guitar and the particular effects app you have on your iOS device. This pedal can turn the app on and off, and works with the AmpliTube app or any other guitar-processing app that uses the iOS mini-jack.
Like effects pedals, multi-effects processors are used to modify and alter the clean signal of your guitar to produce a large variety of effects (reverb, wah-wah, overdrive, distortion, chorus, etc). Unlike a simple pedal that gives you one or two options for modifying tone, a multi-effects processor has a full load of effects and sounds that allow you to play music with a rainbow-colored tonal palette. There are processors for modifying guitar, bass, and even units for vocalists with pitch-correction tools and harmonizer effects.
Some multi-effects processors have other onboard features. Yes, you can run your guitar sound through scores of effects, but many processors even offer modeling that allows you to replicate scores of digitally modeled guitar sounds with a huge range of pedal effects and also recreate the tones of classic combo amplifier and head/cabinet sounds. In addition, some processors give you the ability to loop and delay; some have drum patterns, built-in tuners, recording software, presets as well as user-programmable effects, built-in expression pedals and phrase trainers that record a passage you can play back at varying speeds for learning and practice. Many multi-effects processors now have USB connectivity and you will also find that almost all have ¼” (instrument cable connectors) and XLR (microphone connectors) inputs and outputs. Unlike simple effects pedals, all these features are packed into one compact unit.
Multi-effects processors come in various configurations, too. Some are floor units that have built-in foot pedals and controllers so they can be operated while your hands remain on your guitar. There are rackmount processors (these can be fitted into a rack of recording gear in line with your signal chain) that incorporate a preamp for your guitar. The more sophisticated models have MIDI I/O for connecting guitar synthesizers to keyboards, modules, computers and other MIDI devices and include a divided pickup to attach to your standard guitar. These processors pack effects libraries that offer combinations of effects, amp models and stompboxes that can number in the thousands. Switching can be controlled by onboard knobs, foot controllers or guitar-picking technique. Expect to pay considerably more for a rackmount effects processor, in a range of three- to four-digit prices. Happily, if you’re more interested in noodling and are not seriously recording, at the more affordable end of the spectrum are multi-effects processors about the size of a cell phone, in the neighborhood of 3 x 4 x 1” (w x h x d), for example, which can be carried in your pocket. Even these compact desktop enclosures offer as many as 100 or more different guitar-tone presets and effects as well as USB connectivity, but unlike the floor-pedal models, they do not offer hands-free operation.
New to the iOS market and not available as of this writing, the Alesis AmpDock Multi-Effects Guitar Processor for iPad is a professional guitar processor that you can use with your iPad or iPad 2 for signal processing. This device is compatible with GarageBand, JamUp, AmpliTube and most other CoreMIDI apps. The AmpDock features a durable pedalboard controller with program, effect, bypass, volume and continuous controls, an instrument and a combo input. As the technology develops, the audio world should be seeing more of these devices become available.
Though the line between the two is easily smudged, where multi-effects processors create a broad spectrum of effects, modeling processors can recreate the sound of particular instruments and amplifiers, like a Gibson Les Paul played through a stack of Marshall amplifiers, or a Fender Stratocaster played through a Fender Deluxe Reverb amplifier. A modeling processor offers you the ability to make your guitar and amp combination sound like whatever guitar and amplifier sound you want—even if you don’t own either guitar or amplifier. You are limited only by the number of models programmed into the modeling processor when you plug your guitar into one.
That’s not all modeling processors can do. In addition to offering guitar and amp models, most guitar modeling processors have libraries of the kinds of effects you would get from individual pedals—reverb, echo, chorus, overdrive, distortion, fuzz, etc., as well as integrated drum machines with scores of preset rhythm patterns to help your practice. You can run several effects simultaneously, combining them to create your own unique tonal palette. Most modeling processors now have USB connectivity, some even with two-way audio streaming, for use as interfaces in direct computer recording.
Some modeling processors fit the palm of your hand and you can place them on a tabletop and punch their buttons to select sounds and effects; some are almost two feet long, weigh as much as 10.5 pounds, sit comfortably on the floor and are operated by foot switches or rows of foot switches called pedalboards. Depending upon how sophisticated, complex and pricey your modeling processor is, you can have a huge sonic palette at your fingertips (or underfoot). Many of these units are MIDI compatible as well, allowing you to stream MIDI data to your computer or other recording device, or trigger other MIDI instruments. Just remember that for performance, you will probably be better off with a processor that is operated by foot switches; this allows your hands to remain free for playing your guitar or guitar synth.
We hope that this guide has been of help to you, and we’d also be pleased to answer your questions and entertain your remarks in the Comments section that follows. If you have questions or concerns, please contact a B&H Sales Associate via live chat, over the phone at 1-800-606-6969 or in the B&H SuperStore.