The 27V Super Booster Kit is the cleanest booster you’ll ever find! Why? As most of the boost effect pedals out there, the 27V Super Booster Kit uses a standard 9V power supply. But the magic happens internally: thanks to its charge pump IC, the 27V Super Booster circuit takes the 9V supply and transforms it into a 27V supply. What does that mean? Basically that you can throw input signals three times bigger than you would with a standard booster and the output will be completely undistorted.
– The Treble control you can cut / boost frequencies above 3.3kHz.
Download here the manual for the 27V Super BoosterKit: