Colorsound's legendary Power Boost. Versatile use and outstanding sound. Manlay Sound, led by the Spanish genius Roman, has reissued the Colorsound Power Boost, a pedal used by many rock legends in the 1970s. It is a perfect product in every way, with the excellent build quality that is consistent with his handmade products, meticulous care, and high expressiveness of the subtle nuances of sound. The Manlay Pro Boost is a reproduction of the legendary 4-knob Overdriver, which is particularly popular. It allows for an overwhelmingly wide range of sound creation, from clean boost, crunch boost, treble boost, mid boost, to hard-hitting distortion/fuzz tones. ·power supply The Manlay Pro Boost can be powered by either 9V or 18V. For best performance and headroom, we recommend using 18V (2 x 9V batteries or AC adapter). It can also be powered by 9V and sounds great. Using 9V will result in less headroom for clean sounds and therefore more distortion.・BASS & TREBLE Separate equalization of high and low frequencies・VOLUME The volume on the front panel controls distortion. At full throttle, it's a clean boost, and as you turn it up, it becomes a distorted sound.・Output Volume The pointer knob on the side can be used very conveniently as a master volume.