Boss OD-1

The Boss OD-1 Over Drive is an analog overdrive stompbox released by Boss in 1977, one of the three pedals that debuted the company's compact pedal format alongside the PH-1 Phaser and SP-1 Spectrum¹. It is the pedal that created the "overdrive" category in the stompbox industry², and Analog Man calls it about the first overdrive pedal made and the first of the "tube screamer type" overdrive pedals³. Production ran for eight years, with the pedal discontinued in 1985⁴.

For a player, the OD-1 delivers a tube-like overdriven guitar sound from a small stompbox⁴. Boss describes it as designed with an asymmetrical clipping circuit that reproduces the pleasing sound of a driven tube amp⁵, and the company's own history says that with just two controls it became one of the first pedals to truly emulate the sound of an overdriven amp⁶. A low-impedance input let players explore shades of warm, touch-sensitive overdrive using the guitar's volume control⁷.

The pedal that started the overdrive category

Before the OD-1, "overdrive" was not a stompbox category. Premier Guitar notes the pedal created the now-ubiquitous "overdrive" category in the industry², and MusicRadar describes it as the trailblazing OD-1 that heralded the start of what became a huge overdrive pedal market¹¹. Boss itself states plainly that the OD-1 invented the now ubiquitous "overdrive" category in stompbox effects⁵.

The pedal arrived a year before the better-known Boss DS-1 distortion, which followed in 1978¹. Alongside the Ibanez Tube Screamer, the OD-1 set the standard for tube-like overdriven guitar sound out of a small stompbox⁴. The pedal was subject to various changes throughout its eight years of production⁴, covered below in the versions section.

Two controls: Level and Overdrive

The OD-1 is a deliberately simple pedal. Its face carries two knobs, labeled Over Drive and Level. Guitar World notes the manual described the Over Drive control as producing "soft distortion"¹². There is no tone control, a point that has followed the pedal ever since.

Guitar.com's reviewer observed that even by later standards it was still a fairly simple overdrive with just two controls¹³. The touch sensitivity comes from the input stage rather than the knobs: the low-impedance input allowed players to clean up and shade the overdrive with the guitar's volume control⁷. TONEHOME describes the result as a sound still close to the original signal even though distortion has been added⁴.

Asymmetrical clipping and the circuit

The heart of the OD-1 is its clipping stage. Analog Man explains that the OD-1 (and the later SD-1) use asymmetrical clipping, which Boss has a patent on, to give some thick overdrive with an edge³. Premier Guitar's history confirms Boss already had a patent on solid-state asymmetrical clipping¹⁰. Boss's own article on the SD-1 explains what this means technically: the asymmetrical clipping circuit prevented the distortion of the positive and negative waveform swings equally⁶.

Clipping diodes in the original circuit were vintage Japanese diodes, the Boss BAYP-84A¹⁴. The General Guitar Gadgets replica project, which reproduces the circuit, specifies 1N914 diodes in the D1, D2, D2b and D5 positions, with the D3 and D4 positions left empty, which is how the asymmetry is built¹⁵. The original also included a FET switching circuit and used the 2SC1815 transistor¹⁵.

Versions: quad op amp to dual op amp

The biggest change across the production run is the op amp. The versions break down like this³⁴:

Analog Man is blunt about the difference: the sound of the later unit with the smaller chip was NOT the same as the original version³. He also found the main circuit difference in newer pedals was the capacitors, with several smaller value capacitors used, sucking away low end and making a thin tone³. On the vintage market this matters to price: TONEHOME reports it is a matter of $100 to $200 whether a long dash and clear switch OD-1 sports an RC3403 or any other chip⁴. The 14-leg op amp has a following of its own; Guitar Pedal X notes builders seeking the exact equivalent specs of the original 14-leg Raytheon op amps, which share the same core designation number¹⁴.

The OD-1 and the Tube Screamer

The OD-1 predates the Ibanez Tube Screamer by two years, and the two circuits are entwined. The Tube Screamer was conceived as a competitor to the Boss OD-1 and the MXR Distortion+¹⁶, and Guitar.com reports the original 808 was rumoured to be based on Boss's OD-1, only with the clipping section altered for symmetrical clipping¹⁷. JHS Pedals lists the OD-1 (1977) as the first entry in its Tube Screamer family tree, ahead of the TS-808 (1979) and TS-9 (1982)¹⁸. Guitar.com also notes the first Tube Screamer originally served as competition to Boss's OD-1¹⁹.

The practical difference for a player is the clipping character: the OD-1 clips the waveform asymmetrically, the Tube Screamer symmetrically. Guitar Pedal X's reviewer, comparing the OD-1 against the SD-1 and TS808 in Boss's PX-1, found the OD-1 clips slightly harder and rawer than both²⁰.

The OD-1 and the SD-1

The Boss SD-1 Super Over Drive, released in 1981⁶, is the OD-1's direct descendant. TONEHOME describes the SD-1 as containing the same asymmetric overdrive circuit as the OD-1, which responds very well to the player's attack, plus an additional tone control²¹. Boss frames it the same way: expanding on the OD-1 design with enhanced voicing and a tone control⁵. Guitar.com's jargon buster notes people often lump the SD-1 and its forebear the OD-1 together, and they are very similar pedals and circuits, but the OD-1 lacks the SD-1's tone control²².

Reissues and later appearances

The original OD-1 was discontinued in July 1985⁶, supplanted by the OD-2 Turbo Over Drive¹². Original prices on the secondhand market went sky high a few years before 2022²³. The pedal has since resurfaced in several forms:

• 2017 40th Anniversary Box Set: a one-time-only reissue of the original three Boss compact pedal models, produced exactly as the originals were, with wiring and circuit adjustment performed by hand on a special production line in Japan²⁴.
• PX-1 Plugout FX (2025): the OD-1 is onboard effect 1 on Boss's first compact digital multi-FX pedal²⁰.
• OD-1X: a modern Boss overdrive pedal with four controls, level, low, high and drive²⁵, which Boss says uses its MDP engine to dish up refined overdrive sounds that smoothly integrate with nearly any amp platform, from light edge-of-breakup to mid-boosted gain for singing leads²⁶. MusicRadar notes it is unlike the analog original⁸.

The circuit also lives on in third-party pedals, from the General Guitar Gadgets replica project¹⁵ to the Drunk Beaver OD-1, a 14-leg op amp take on the design¹⁵²⁷²⁸, and the 1989 Exar OD-1, a Polish copy of the Boss original²⁸.

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