Editor's note: This tour of small businesses across the country highlights the imagination, diversity, and resilience of American enterprise.

It was a ZZ Top Christmas miracle.

In 1996, camped out in an apartment with a busted furnace, Zachary Vex, broke as usual, was gamely trying to assemble his Fuzz Factory model guitar pedals. This was December in Minneapolis, so the temperature inside topped out at 55 degrees in daytime. Vex, shivering in a parka and fingerless gloves, was struggling to operate a soldering iron when the phone rang. It was Greg Bayles, owner of Make'n Music, a guitar store in Chicago. Bayles told Vex that ZZ Top guitarist Billy Gibbons had just come in, bought up the store's entire stock of Z.Vex Effects products, and wanted more.

Soon after, "Gibbons called me and bought everything I had," says Vex, now 54. "It was mostly destined for Christmas presents for his friends. I made enough money from that to get into a different apartment and be warm again."

Z.Vex makes effects pedals: electronic devices that plug into electric guitars and amps to change the sound, or--in the case of Vex's products--to push the sound to the edge of madness. For years, Vex played a minor role in Minneapolis's eclectic music scene as an audio engineer, until one day his tinkerer's passion brought him front and center. This is a guy who almost didn't launch because he thought his products were too weird. Today, he sells roughly 20,000 pedals a year to bands shredding in private basements and public arenas.

Minneapolis is less celebrated for music than, say, Austin or Seattle. But it's still a hell of a music town, having spawned, among other bands, The Replacements, Soul Asylum, Hüsker Dü (OK, they're from St. Paul, but still...), and the simultaneously flamboyant and enigmatic Prince, who filmed the movie Purple Rain there. In 1998, the Minneapolis band Semisonic used two Fuzz Factories to record the hit "Closing Time" at a local studio. In an interview, Vex uses his voice to simulate the pedals' effect on that song's guitar solo. Mimicking sounds is something he does frequently: entertaining but impossible to reproduce in print.

"Musicians need something exciting that makes them sound completely different from anyone else," says Vex. "I want to give them the sensation of, 'OK, I'm somebody now. I stand out.'"

For 20 years, Z.Vex's bestselling pedal has been the Fuzz Factory, used by, among others, Jack White of The White Stripes, Trent Reznor of Nine Inch Nails, and J Mascis of Dinosaur Jr. The company's more than two-dozen other models include the Woolly Mammoth, the Box of Rock, and the Super Hard On. "It's super hard on your amplifier," Vex explains. "It's a running gag in the business to make your pedals' names sound as obscene as possible."

Music writers have dubbed Vex the "mad scientist" of his industry. "He was the pioneer of let's-throw-all-this-together-and see-what-kind-of-crazy-sound-we-can-get," says Alan Sparhawk, guitarist for the Duluth, Minnesota indie band Low. Sparhawk owns three Z.Vex pedals: the Octane 3 is his favorite. "It's super-chaotic, especially live," he says. "It's like, 'OK, I need a pedal that suddenly makes the guitar go everywhere, like a giant spider.'"

"When some guitar players plug in the Fuzz Factory they think, 'This is just crazy. Why would anybody use this?'" says Nate Westgor, founder of Willie's American Guitars, a Minneapolis institution and the first store to sell Vex's products. "But others see it as groundbreaking."

He's with the band

Raised in the Minneapolis suburb of Bloomington, Minnesota, Vex first encountered guitar effects in grade school. He and his brothers would experiment with a couple of Gibsons in their uncle's basement, and when the knobs on the Jordan Boss Tone pedal would break, Vex, with his small fingers, would fix them. He built his first pedal in high school from a fishing-tackle box and Radio Shack parts, and sold it to another student for $10. In 1981, he dropped out of the University of Minnesota "because they stopped teaching me anything I was interested in." No big loss--he had already been banned from working in the physics building after accidentally blowing up some computers while trying to build a Tesla coil.

To make a living, Vex worked as a technician at companies like Control Data and 3M. On the side, he cobbled together new guitar amps out of old guitar amps--trying to make them sound more exciting. Then Prince began to party like it was 1999. "I thought, 'Hey, if one guy from Minneapolis can make it in the music scene, so can I,'" says Vex. He built a tiny studio in his apartment where he recorded his own songs, then delivered the cassettes to a DJ at a low-budget public-radio station in the middle of the night and sat outside in his car listening as she played them. When he started bringing other bands to record at his apartment, his landlord threatened to kick him out. Vex rented a storefront for $400 a month, and he and a partner, Scott Tuttle, launched Underground Studios. The two shared engineering duties and "generally let the bands produce themselves," says Vex.

Over six years at his studio, Vex recorded artists like Grant Hart of Hüsker Dü, Dave Pirner of Soul Asylum, and Ingrid Chavez, star of the Prince film Graffiti Bridge. More often, he recorded amateurs. "Bands would come in and spend their life's savings. Then, when they listened back on what they'd played, they'd be like, 'Oh my god! We don't know what we're doing,'" says Vex. "I would pull out my arsenal of effects pedals to give the guitarist a completely new sound." Pedals had fallen from favor in the '80s, however, and few companies were making them. Vex found his choices frustratingly limited.

In the early '90s, new, inexpensive home-recording equipment deep-sixed Underground Studios. Vex became an independent recording engineer. But working with hardcore punk bands, he developed tinnitus. In 1994, he took off time to let his right ear heal and generally clean up his life. ("I had been drinking kind of hard," he says.) He also resumed his electronics projects.

Wild and beautiful

The first pedal Vex built in this period was the wild and noisy Octane. He painted it himself, because he couldn't afford silkscreen and because no one had ever before tried making pedals--unlike guitars and amps--beautiful. With no expectations, Vex showed the device to Westgor--"just because I was proud of it." Westgor immediately became a customer, Vex says, "and suddenly I was in business."

For the Fuzz Factory, which he developed over the course of one long night, Vex used vintage parts purchased from a store in St. Paul. Again, aesthetics mattered. "They had a bin full of transistors that looked like tiny Spam cans. They were too cute not to use," he says. "There were orange capacitors that looked like little tear drops."

Soon, Vex was selling through such respected independent stores as Rudy's Music in New York City. Z.Vex products exploded in Europe after Matt Bellamy of the British band Muse had a Fuzz Factory built into his guitar. Today, Guitar Center accounts for 20 percent of Z.Vex's sales: an uncomfortable position given that retailer's uncertain future. Still, Z.Vex continues to add accounts worldwide, and online sales are healthy.

Unlike many music companies, Z.Vex even managed to hold sales steady during the recession. "You can't sneak a new amplifier past your wife," says Vex. "Whereas if you have a pile of guitar effects on the floor and you add another one, you can probably get away with it."

Today, Vex and his five-person staff produce 3,000 to 4,000 pedals a year in a 7,500-foot office and warehouse in St. Louis Park, immediately west of Minneapolis. The pedals are all hand-built and hand-painted and--at a cost of $239 to $700--on the high end of the market. (Pedals are made by a few large companies, like Boss, and a slew of small ones, almost all of which sprouted post-Z.Vex.) Vex contracts out production of another 20,000 pedals to Taiwan and California. Those pedals, too, are hand-built, but they cost less, from $99 to $300.

Home, for Vex, is three hours from the factory: a log house built on a man-made cliff in Minnesota's Driftless Area, a region of rolling hills and river-carved valleys. He dreams of retiring there someday, but has no firm idea of when or how. "I don't know anyone in this industry who has an exit strategy," Vex says. "Every single person I know with a music-equipment business has taken it to the grave."