The Line 6 DL4 Is Quietly the Most Important Guitar Pedal of the Last 20 Years

The intuitive delay pedal known as the Big Green Monster helped spread looping across experimental rock.
The Line 6 DL4 delay modeler aka the Big Green Monster
Pedal photo by Total Guitar Magazine/Getty, treatment by Martine Ehrhart

“It’s possible the past 10 years could become the first decade of pop music to be remembered by history for its musical technology rather than the actual music itself,” wrote Eric Harvey at the end of the last decade. He was referring to the impact of the mp3, but the idea rings just as true for creators as it does consumers. As technology democratized around the turn of the century, digital audio workstations like Pro Tools revolutionized the home studio, and ultimately changed the course of music with their boundless potential.

A less commonly discussed breakthrough of the era involved musicians’ outboard gear, such as guitar pedals, which moved from analog to now-inexpensive digital architectures. Chief among the hardware that benefited from this shift were delay pedals, a class of effect pedal that gives an echo or repeating effect to a sound. Delays were generally expensive, since they required either actual tape loops or expensive memory within their makeup. Digital technology changed that, introducing with it the kind of lower-priced loop pedals that encouraged experimental strains of ’00s indie rockers to recreate with live instruments a similar effect as sampling. There was one pedal in particular that emerged as a favorite: the Line 6 DL4 delay modeler.

Radiohead fiddled the knobs of the DL4. Andrew Bird utilized two DL4s to create his glitched-out violin loops, as did Kishi Bashi. Grizzly Bear were known to have a DL4 or two on stage. Deerhunter’s Lockett Pundt had one on his pedalboard. Bill Frisell and Sarah Lipstate, aka Noveller, both used the pedal to create their expansive and florid guitar soundscapes. And Battles, arguably the wonked-out kings of ’00s indie-prog, could not deny the presence and influence of the DL4. The band’s vocalist on their breakthrough 2007 record Mirrored, Tyondai Braxton, utilized DL4s to achieve the unique sound of his vocals. He still has them on his performance rig today.

“It really was kind of omnipresent just because of what it did and how inexpensive it was. Maybe it was the Big Muff of our generation,” Braxton said, referring to the distortion pedal that shaped several generations of fuzz guitar sounds. “I hadn’t been thinking about that as a tool of such importance, and then suddenly, 15 years later, you look back and actually I used that thing quite a lot. I played that pedal more than I played any other instrument of the past 20 years.”

The fledgling amplifier company Line 6 wasn’t expecting to influence a generation of loopers when it started branching out into effects pedals in the late ’90s. One of its first missions was to create a series of stompbox modelers that would mimic the sounds of many other pedals, all at once. There was the DM4 distortion modeler, the FM4 filter modeler, the MM4 modulation modeler, and, most famously, the DL4 delay modeler. Engineer Jeorge Tripps, founder of the Way Huge pedal company and now an engineer at Dunlop, was brought in by Line 6 in 1998 to help design that entire line.

“The whole feel of the DL4 was, ‘This needs to not feel like a digital product,’” Tripps said. “Does it bake your cookies for you? No. It’s giving you a whole lot of sound, but it’s working pretty traditionally.” Simply put, the DL4 was a digital delay that behaved with the ease of a classic analog device, making it a go-to device in a transitioning time.

Since the DL4 is used most often in these contexts to lasso and manipulate sound rather than to produce it, you don’t necessarily “hear” the pedal on every record it appears. But the Big Green Monster, as it’s sometimes referred to, is quite easy to spot onstage. It’s nearly a foot wide with four stompbox switches, and it’s painted deep, metallic green. There’s a mode switch knob, to change between different styles of delays, and five mod knobs, that change the speed, timbre, length, and tone of those delays. But for the loop function—without question the most influential aspect of the pedal—those four knobs are fairly intuitive, especially compared to other loop pedals at the time, with their LED screens, memory banks, quantizers, and beat-matching functions. The DL4 was simple: hit one button to record, hit it again to stop recording. Another button could play the loop in halftime, a third button could play the loop from the beginning. The fourth switch simply stopped recording.

“The simplicity of what we chose is what ended up being attractive, because making real-time music is a right-brain activity,” said Marcus Ryle, the CEO of Line 6 and one of the pedal’s engineers. “It’s a fully creative activity. And when products get too complex, you suddenly have to be left brain and analytical to run them. Just having four buttons and a handful of knobs, people just got to where it was purely subconscious and second nature how to operate it.”

The DL4 first entered many artists’ arsenals because it could recreate so many different sounds, an effect that previously had been pricey to achieve. In fact, the loop function initially was seen as secondary to the multitude of delays—almost a bonus of the device. Musician, beatboxer, and comedian Reggie Watts started using the pedal when it first came out because he wanted to mimic a Roland Space Echo, a tape delay effects unit from the 1970s that wouldn’t travel as well on tour. But it was the DL4’s loop function that would eventually dominate Watts’ oeuvre: He often uses several of them in tandem to layer vocal beats and singing. “And I don’t use the other modes at all,” Watts added.

A similar story is true for Dave Knudson, guitarist of the math-y indie rockers Minus the Bear. “I was only using it for delay, and then at some point I was like, ‘Let’s see what this looper thing is.’ From there, it just went deeper and deeper. It’s been a point of inspiration for me for a long time and even to this day.” Revered by guitarists for his double-handed tapping technique, Knudson has been known to use as many as four DL4 pedals at a time now. But the clipped fingerprint of the DL4 loop first emerged in Minus the Bear’s catalog on “The Game Needed Me,” the opening track from the Seattle band’s second LP, 2005’s Menos El Oso. “When we were writing Menos El Oso, I was really into Four Tet, Caribou, DJ Shadow, Amon Tobin, kind of sampled, cut-up sounds,” Knudson said. “I was trying to figure out a way to replicate that and the DL4 did it.”

What you can hear on that record, and so many others, is how the DL4 became an indispensable composition tool. Not only can you loop a sound, but you can put that sound in halftime, in reverse, or trigger only a part of the loop. It also doesn’t bend the loops to any quantized grid, meaning “computerized” sounds could be played in human ways.

Dave Harrington, career guitarist and one-half of the experimental electronic duo Darkside, said he simply can’t do what he does without the DL4. He’s even had guitars modified so they can communicate with and control the pedal, which is responsible from the looping across Darkside’s 2013 debut, Psychic. “The DL4 became a part of my language on the guitar,” he added.

“That’s how they get you, because you start to incorporate how the pedal operates into the way you work,” Braxton said. “So then you rely on it. And you have to keep getting it.”

He means “you have to keep getting it” in the sense that, especially for experimental musicians who tend to be not so gentle with their gear, the DL4 has not always been known to be entirely reliable. That’s the reason Knudson keeps three in his reserve. Braxton estimates he’s been through about a dozen, Harrington the same. My own atmospheric industrial duo, Yvette, has been through too many to count; in fact, we modify our DL4s with an outboard trigger switch, so as not to disturb the pedal’s delicate architecture. Watts thinks he’s run into the double digits on his DL4 count. Brian Chippendale, the powerhouse noise drummer and vocalist of Lightning Bolt, has had as many as 10 in various states of disrepair laying around, after having used the pedal live since the early ’00s and on record since Lightning Bolt’s 2005 LP, Hypermagic Mountain.

“It is like a true human relationship,” Chippendale said. “It’s like you’re in a band with a genius, and they only show up to one-fifth of the practices. And you’re just like, ‘I guess that's just the way it is.’”

After nearly 20 years, not much has changed about the DL4, especially that distinctive green (“Delays are just always green to me,” Tripps said.) While several artists told me they’d begged the company for a version of the pedal that encompasses just the loop functions, the only upgrade has been the logo on the box. Line 6 engineers have moved on to more advanced technologies, and the DL4, as ubiquitous as it remains, is in their rearview. Still, it’s the most-consistent selling pedal in Line 6’s stock.

“The typical curve for a technology product involves dying away as technology evolves,” Ryle said. “But occasionally, some end up having such a distinct personality that they carry on. That’s certainly the case with the DL4.”