Boss SD-1-4A 40th Anniversary Special Edition Super Overdrive Pedal (Discontinued)
Limited Edition 40th Anniversary SD-1 Super Overdrive (SD-1-4A)
To celebrate 40 years of continuous SD-1 production, we've created a limited edition version that's available throughout 2021. This commemorative pedal features a black body with yellow lettering, gold-capped knobs, and a vintage silver thumbscrew for the battery compartment and comes in a box with a special 40th Anniversary logo.
Super Overdrive Sound
Since its release in 1981, the workhorse SD-1 Super Overdrive has been the core gain pedal for generations of players across every musical genre. Based around the revolutionary asymmetrical clipping circuit from the OD-1 Overdrive—one of the three original BOSS compact pedals from 1977—the SD-1 delivers rich, smooth, and highly musical overdrive tones that continue to inspire guitarists everywhere.
Genre-defining BOSS overdrive sound
Unique asymmetrical clipping circuit produces tube-like overdrive characteristics
Mild-to-moderate drive tones with focused midrange and tight low end
Ideal for use with clean and slightly driven amps
Also works great for bringing tightness and definition to high-gain amp tones
Stacks well with boost, overdrive, and distortion pedals
BOSS five-year warranty
The Clipping Circuit That Defined “Overdrive”
In 1977, BOSS created an entirely new stompbox category with the OD-1, bringing natural overdrive in pedal form to guitarists for the very first time. Producing a signal rich in even-order harmonics, its unique asymmetric clipping circuit replicated the pleasing sound and feel of a driven tube amp—but at controllable volume levels. Four years later, this breakthrough design evolved into the more versatile SD-1, which added an active tone control for shaping the treble response and subtle enhancements for more low-end body.
The SD-1 allows players from beginner to pro to get inspiring sounds right away, thanks to its natural behavior and the subtle mid boost that's part of its design. It gives your tone a push where it matters most, ensuring your guitar always sits perfectly in the mix with warmth, clarity, and rich presence. Lower drive settings are great for rhythm parts, while higher settings are ideal for fat, singing leads. The SD-1 is also very sensitive to input gain, letting you dial in different shades of overdrive simply by adjusting your guitar's volume control.
The One Pedal Every Player Needs
With its organic character and responsive drive and tone controls, the SD-1 delivers the right sound for just about any style of music. Kick on the pedal with your favorite clean or slightly driven amp for mild-to-moderate overdrive that’s ideal for everything from classic rock and gritty blues to pop, country, jazz, and beyond. The SD-1 also shines as a booster for high-gain amps and other drive pedals, providing mid focus, tight bass, and smooth top end that's perfectly suited for heavier sounds and solo playing.