PedalPro has an ultra low noise boost (pre-amp). You can use it together with the distortion as a distortion gain, on its own, or in combination with the other effects to really boost your sound.
Thanks to the opto resistor control, the boost gain can be controlled remotely via an expresison pedal in a fluid and glitch-free manner. In this way you can use it either as a volume pedal or like a saturation control for your distortion/amplifier.