The Perseus Dio greatly expands on the concept of our original device, giving you a three-voice all-analog octave down device with adjustable octave filters. Three knobs control the mixer section, giving you one octave down, two octaves down, and a dry, boosted distortion. The Dry knob gives you a really great light distortion sound that's more than capable of pushing your amp into overdrive, but the fun starts when you control the levels of octave down signals with their accompanying low-pass filters. With no filtering, the octaves are harmonically rich square waves that sound like old-school Nintendo, but turning up their accompanying filter knobs smooth out the harmonics and turn into clean octaves down. Controls - Down 1: Level of the 1-octave-down signal. - Filter 1: Cutoff point for a second-order low-pass filter on the Down 1 knob. At minimum, cutoff point is 7KHz, retaining all the harmonic richness and video game-esque qualities. At maximum, cutoff point is 280Hz, giving you a clean octave down with bubbling harmonics lying underneath. - Down 2: Level of the 2-octave-down signal. - Filter 2: Cutoff point for a deeper second-order low-pass filter on the Down 2 knob. At minimum, cutoff point is 7KHz, just like Filter 1. However, at maximum, cutoff point is 140Hz to let the power shine through at higher settings. - Dry: Volume of the dry signal. It is not your true clean guitar signal, but rather a boosted version of it, allowing it to mix better with the octaves. There's plenty of volume on tap and it sounds great just by itself.