OpenStomp: Open Source, Meet the Guitar World

In the guitar world, analog purists typically look at digital proponents with a wary, disdainful eye—these are the people, after all, that believe technology can trump tradition, a touchy subject in the guitar world. Eric Moyer, the California-based creator of the open source OpenStomp—a device so unabashedly digital and computerized that many of its deepest functions require a technical degree— shrugs it off with in Huntington Beach surfer style.

“I love digital effects pedals. The sound quality of analog stuff is great, but there’s a versatility with digital stuff that I just adore,” said Moyer from his office, located a stone’s throw from the ocean. “I’m a huge fan of the Line 6 stuff—I love being able to get in there and tweak things, and there are some things that you just can’t do in analog.”

Eric Moyer

Moyer, who pays his bills with a start-up medical device company and describes himself as a “techhead, an iPhone guy,” is the sole mind behind the OpenStomp Coyote-1, a completely digital and customizable effects processor housed in an unassuming purple box.

Simply put, any user can use Moyer’s homegrown software, called OpenStomp Workbench, to build patches and assign functions to the unit’s four top-mounted knobs and two sturdy footswitches; more intrepid users—likely those with computer science degrees and an affinity for assembly programming language—can use the software to design their own effect “modules,” such as echo, delay and distortion. Those modules can then be used by anyone and strung together, virtual wire by virtual wire, into the aforementioned patches and loaded onto the unit.

If the Coyote-1 sounds like a truly boutique, niche product, aimed at techhead guitarists who would rather spend their time compiling code than evaluating boutique ODs, you’re partly right. Moyer sunk 16 months of his time into the development of the Open Stomp, and bypassed the use of a typical DSP chip for the Propellor, a multicore processor similar to the one found in a Playstation 3 (the standard DSP route, “just wasn’t interesting enough to get me out of bed in the morning and make me do it.”). That’s not to mention that the process of creating new modules for the OpenStomp requires some savvy programming skills, enough so that Moyer has been solely responsible for most of the existing modules, mostly utility modules such as choruses, tremolos and distortions, and currently numbering 15 in all.

But the brilliance and greater appeal of the Coyote-1 reveals itself in its ability to redefine how guitarists interact with the effects. While the OpenStomp system is certainly capable of standard digital tasks like aping classic overdrives and crisp delays, its greater strength lies in its ability to allow users with average computer skills to create previously unheard effects in OpenStomp Workbench, by stringing together pre-programmed modules, all in a graphical interface that resembles a paint program.


OpenStomp Workbench
“A very simple example would be to take a chorus effect and an echo effect and just chain them together, so now you get chorus and echo at the same time. But a more complex example would be if you took an LFO module and chained [its output] to the on-off function of a distortion effect. Now you get a distortion effect that cuts in and out rhythmically. And if you get enough weird low-level modules like this—LFOs, pitch detectors, volume gates—you can start to create these unique, creative things by simply chaining them together.”

“I don’t want to spend a lot of time trying to be a ‘me too’ pedal,” Moyer added. “I want to take things in different directions and try to do things that haven’t been done before. There’s merit to having chorus and distortion and delay, because people can relate to them, but it’s time to take a hard left and create some weird effects.”

In fact, it’s such a revolutionary concept that Moyer has had a hard time communicating the possibilities to guitarists, who are used to connecting effect pedals with a few inches of cabling and turning them on and off. It can take a while to mentally click, and Moyer has accepted that as his efforts have turned from design to marketing and community building.

“It’s a different paradigm than people are used to. It’s something that they haven’t been able to build before. It takes some vision to get there on your own. I don’t kid myself—if you talk about something like an effect where your distortion cuts in and out rhythmically, it’s not the kind of thing you’re going to bust out on every song. I don’t by any stretch expect to replace something like a [Line 6] POD XT Live, but there are workhorse effects in there that you could run all day onstage, and there are some bizarre things you can do with the OpenStomp that you just can’t get anywhere else. It falls into that boutique digital pedal niche.”

But for guitarists who buy into the paradigm and have some spare time and a digital aptitude, the OpenStomp platform could provide them with a new set of tools for self-expression. The Coyote-1’s open source nature gives it a wide range of capabilities, and while Moyer guessed that some more advanced features like amp modeling may be beyond the horsepower of the Propellor processor, he noted that “people keep finding new ways to pull new tricks with it, so it’s hard to say what’s truly capable in the end.”


For now, Moyer is hard at work on Mac and Linux versions of the OpenStomp Workbench—two major constituents of the open source movement—and is continuing to sell the Coyote-1, one by one through his website, to any musician curious enough to plunk down the $349 entry fee.

It seems to be spreading, slowly but steadily. The OpenStomp forum continues to attract new members, and the discussions are getting more robust, more technical. There are more ideas tossed around and more options pondered—how can I do this? Is this possible? You can literally see people beginning to engage with the technology to create brand new sounds, which was Moyer’s goal when he first came up with the project on a caffeine-drenched evening in June of 2007.

“This is kind of a jump to the left, in a fun way. I don’t expect the POD XTs of the world to disappear one day in favor of open source effects, and there’s good reason for those guys to keep their intellectual property internal. But there’s a big space in here that nobody is playing in, and there’s a lot of fun to be had,” said Moyer. “I’m not surprised the big guys haven’t gone and done it, because it’s a boutique product, but I don’t eat my dinner at night based on how these things sell, so I’m free to just try and make something cool.”

openstomp.com