Product Description

This pedal is a key element to many heavy rocker’s tone. It’s like the TS9 with more transparency and more edge.
If you are looking for something in the Tube Screamer vein, but with a little more hair on it, not as much midrange push, this is it! Plus, this mod has a Germanium diode in the clipping section as a standard part of the mod! The Super Overdrive, GE 5 STAR MOD! Complete with metal film capacitor and resistor upgrade. Increased Bass, Drive, and Fidelity.
This is not just a switch to make it like a TS9 as some folks do. This makes it much fatter, cleaner, and more defined, and gives it another mode to increase the gain beyond what a stock SD-1 offers!
We have improved the BOSS switching to make it even closer to true-bypass! In stock form these units may suffer a bit of bleed through when off if the level and gain are set very high. But now with the new and improved bypass we now have the best sound pedal both on and OFF!
Additional Description
Now with a unique twist, the Diode Switch is a standard feature instead of an option. This allows players to get a really heavy sound for pushing a Marshall amp, etc., or to use it as a really fat sounding tube amp simulator! Perfect for both single coil and humbucker guitars!
Two TI RC4558P ICs stacked inside for clarity, noise reduction, and a mini-toggle for tons of tone options.
Our SD1 5 Star Ge mod includes a two way gain switch that allows you to select between two different diodes for the clipping/distortion section of the pedal. The “down” position selects a germanium diode (the “Ge” part of the name). The Ge diode clips the signal more than a standard silicone diode, providing a more saturated, compressed, and smoother sound with more distortion available. The “up” position selects an LED for the clipping section, which clips less, allowing a clearer, more “open” sound, with less compression, more dynamic response, and more output available. Both are asymmetrical and both are an attempt to make the pedal more ‘tube-like’ since tubes and transformers rarely produce a symmetrical distortion.
Purchase Options
New Pedal w/ Mod
Keeley SD-1 mod w/ new diode switch. Going on 9 Years of Keeley Mod Perfection. Set the standard for boutique hot rodded distortion boxes!
Mod Only (Send us your pedal)
We modify yours! Blue LED, Two TI RC455P IC ICs stacked inside for clarity, noise reduction, and a mini-toggle for TONS OF TONE options. Improved bass response, and truly toneful caps replaced everywhere! Better Bypass scheme.