This Boss DS-1 mod adds more than you would expect to the tone. It has 3 different gain settings, controlled by a 3 way switch: boost, crunch (my favourite), and drive, each more unique and different from stock boss DS-1 tone, respectively. Boost (top position), the lowest amount of gain you'll get, is presented as more of a clean boost (as the name implies), something similar to a tube screamer. Crunch (bottom position), provides more gain than the boost but I think it has too much gain to be used as a "crunch" tone from a clean, a lot more brittle and full than the others. Drive (middle position) has the most gain, and is the smoothest sound you'll get from this pedal, though it sounds a bit electronic at higher gain. As much as I miss the straightforward tones of Boss's stock DS-1, I don't think I can ever go back, this mod just adds too much to the sound of the guitar. If you think your Boss DS-1 sounds too flat, or just need more gain out of it - JHS Pedals made the Lexi mod for you.