Roots Radical: Boss OD-1 Over Drive

od-1.jpg

Back when electric amplifiers first hit the scene, distortion was a major problem, one that engineers worked overtime to solve. Distortion occurs by pushing the signal beyond the threshold it was designed to work within (headroom), and the signal is clipped. This clipping kicked sand in the face of the dulcet tones that were first associated with electric guitar, thereby defeating the entire purpose. As time went on, bigger amps were developed with the hope that distortion would be left behind. It wasn’t, and it soon became a desirable feature. Rock ’n’ roll was soon born.

Now, with amp distortion as the fundamental building block of rock, there was just one problem: the volume that came with it. What if budding rock ’n’ rollers could summon the powerful tones of amp-like distortion on demand? This was the guiding principle behind the Boss OD-1 Over Drive, an extremely important pedal throughout history. Not only did it introduce the word “overdrive” into the guitar lexicon, but it’s become so ubiquitous that everyone has heard one.

“Wait,” you might say. “I’ve never heard an OD-1, and I don’t know anyone who makes a clone of it either.” Sure you have. You might know it as the Tube Screamer.

Though they’re not identical, they share an overwhelming number of similarities, enough to where a looming threat of litigation shaped the development. As the story goes, Boss developed the OD-1 with amp-like crunch in mind, and set out to make a distortion pedal in that vein. The plan was to utilize clipping diodes in the feedback loop of an operational amplifier, or op-amp, a technology that was relatively new. The idea was simple: placing two uneven sets of clipping diodes in the feedback loop would deliver asymmetrical clipping, which is similar to how real tube amps clip when pushed. The effect was so pronounced and dramatic that Boss ended up filing for a patent for it. The pedal itself was released in late 1977.

When Susumu Tamura of Maxon set out to create the Tube Screamer, he was doing so in order to directly compete with MXR’s Distortion+ and the Boss OD-1. In the end, the Tube Screamer competed mostly with the OD-1, featuring a name that conjured up the idea of a cranked amp and a nearly identical circuit topology. The major roadblock was the asymmetrical patent, but it was easily sidestepped by using the same diode on both “sides,” resulting in symmetrical clipping. A rudimentary tone circuit was also added. Boss later combatted this by releasing the OD-2 in 1985, which added a tone control and a “turbo” mode to the original.

After the TS-808 came out, no holds were barred in the overdrive arena, and the pedal world is positively filled with Tube Screamer copies—and by proxy, Boss OD-1 copies. The OD-1 topology is important to the history of guitar pedals in a few ways: For one, it laid the fundamental groundwork for the very definition of “overdrive,” known now as soft clipping in which the diodes to do so are placed within the feedback loop of an op-amp. For two, it demonstrated the need for guitar players to have a “transparent” overdrive in their arsenals—the original ad copy said that the asymmetrical clipping creates a sound that is ”still close to the original even though distortion have (sic) been added,” which is a roundabout way of saying “transparent” before the word was commonplace. You might then say that the Boss OD-1 is the first transparent overdrive, which opens up a huge can of worms.

Indeed, the tone of the OD-1 is raw and extremely amp-like. I wouldn’t necessarily call the sound “transparent,” though the sentiment is certainly there. There are four known versions of the OD-1, with the final two being overwhelmingly common. I owned the second silver-screw version, with the RC3403ADB op-amp—the same op-amp used in the first version—and the sound was crunchy, focused, and didn’t get overwhelmingly loud for a wide range of usable values.

od_3_gal.jpg

The OD-1 is extremely touch-sensitive, like any transparent OD, and is similarly sensitive to slight changes in your guitar’s controls, for an extremely expressive and decidedly vintage tone that shakes hands with your amp instead of eyeing it from across the room. It is currently commanding some serious added value in the used marketplace for its collectibility and the mojo-drenched tones that lie therein.

Its lineage gives way to the current-issue OD-3 that’s been made for 21 years. It features a dual-stage design that strays from the path of the original, but the OD-1 magic is present in the second half of the circuit for an augmented sound that’s one of the finest drives around for under a C-note. As the very inventors of overdrive (or “Over Drive” if you prefer), Boss writes its own rules.

Joseph Rubenstein