Subdecay Octasynth Octave Synthesizer Pedal Blend- A mix control for 3 octave voices. To the left, two octaves down. To the right, one octave. In the center a mix of all three. Blend- A mix control for 3 octave voices. To the left, two octaves down. To the right, one octave. In the center a mix of all three. Res- Resonance/Feedback for the filter. Turned to the right the cut off frequency of the filter is intensified. Turned all the way to the right the filter will approach near oscillation. Level- Total output volume.