The blend knob adds your dry signal into the envelope & fuzz. Hendrix to SRV. & just about any psych music out there. Full of features, & it lives up to the reviews. It is able to retain that octave at very high gain & volume settings. No battery power. 9v wall power. I keep putting it back on my board, it’s following fuzz envelope & univibe, it’s handling them just fine & it’s always easy to quickly dial in some new Eq & high gain octave or not. The blend knob is super responsive. $225 OBO