Guitar Multi-Effects Processor Buyers Guide
Multi-effect processors add a variety of variables, as it’s rare to find a single piece of gear that will serve every need you’ll ever have in your rig. Fortunately, they can often serve multiple purposes quite well, making them an adequate addition to your setup.
It’s most important to assess exactly what you’re looking for. Do you need a pedal to be primarily used live or do you want a rack unit designed for easy studio integration? Are there particular effects that you want to use the processor to cover? You’ll definitely want to test your options before buying, but there are several things to keep in mind before even getting to that point.
Effects Types
Multi-effects processors offer up several different effects types or categories. Some processors specialize in one specific type, while others provide a wide range drawing from all of them.
Overdrive
Overdrive effects encompass all kinds of distortion, overdrive, and fuzz sounds. These are great for loud rock music, heavy metal, and any other genre that requires an effect to highlight solos or lead melodic lines.
Filter
Filter effects alter the equalization frequency of the processed guitar sound. These include high and low pass filters, envelope filters, and any other effects sweeping through, cutting out, or boosting the high, mid, and low frequencies. Filter effects can clean up and fix an undesirable sound, or transform it to take on specific characteristics not normally found in a guitar; for instance, utilized so a guitar signal sounds more like a synthesizer
Reverb and Delay
Reverb and delay effects don’t so much transform guitar sound as they enhance it, often by providing an echoing reverb or repeated delay to the signal. These types of effects can be as basic as reverb and delay, but can also include reverse mode in which the signal is played backwards, echo, and more.
Flanger
Flanging duplicates the original signal of a guitar’s output but delays one signal by a small and gradually changing period. The resulting sound is similar to a comb filter effect – one that has been characterized as “sucking air” and/or “the Darth Vader effect.”
Although wildly popular as a guitar effect, flange was first popularly utilized by producer George Martin during recording sessions for the Beatles. John Lennon would often use the effect on his vocals; in fact, historian Mark Lewisohn claims that it was Lennon who first gave the technique it's namesake. The first Beatles song to feature the flanging effect was “Tomorrow Never Knows” on their album Revolver; almost every single song on that record had some sort of flanging effect on it.
Whether used subtly to suggest a spacey feel or cranked all the way up to create an unnatural, synthetic-like sound, flanging is a guitar effect that doesn’t seem to be losing popularity anytime soon.
Chorus
Chorus duplicates the original output signal and alters it slightly so that the signal sounds like it’s being voiced by multiple sources – or, as the name indicates, by a “chorus” of instruments. Chorus is a great way to thicken up the sound of a guitar part, and can be used with other effects such as distortion to expand multiple layers of tones within a signal.
Perhaps one of the most instantly recognizable uses of chorus in popular music is the beginning intro guitar riff to “Come As You Are” by Nirvana. Like tremolo, chorus effects are often built into guitar amplifiers; however, working with processors like pedals (which are solely designed to produce this effect) will almost always result in a better and more nuanced sound.
Phaser
Phasing (also referred to as phase shifting) does exactly what its title suggests – a signal is duplicated, and then that new copied signal is shifted to be out of phase with the original signal. The resulting sound creates a spacey, “whoosh” effect that brings to mind watery atmosphere.
While signal phasing can sometimes be an unwanted by-product of audio recording, the effect began to be used intentionally on psychedelic records in the late 1960s, notably on “Itchycoo Park” by the Small Faces. The effect was later popularized in decades to follow from guitarists such as Eddie Van Halen, Queen’s Brian May, and Incubus axeman Mike Einziger.
Downloadable Content
Many recent processors allow you download and update the library of effects within the unit as new ones become available. This can be accomplished via memory cards, Bluetooth technology, mobile apps or digital downloads to refresh the processor’s library of sounds and effects. Although this is a relatively new technology within the world of guitar multi-effects processors, this is likely to become the standard in the years to come.
Usability and Customization
While processors come pre-built with the sounds and organization already pre-determined, many guitarists enjoy multi-effects units because of their ability to change their workflow as well as the sounds/effects they produce. For instance, many units come with blank slots in their effects libraries so guitarists can tweak and edit sounds on their own before saving them as presets for later use.
In addition to crafting and shaping the sounds, users can also control how the effects are accessed through the processor; a guitarist can save specific sounds so they’re readily available by simply tapping a button or flicking a switch. This is especially useful for guitarists playing live who need to have specific effects at their fingertips (or more accurately, their feet) for quick and easy recall.