In video #06 of my series on the Behringer Model D we take an in depth and extensive look at the filter section. The Moog Low Pass Ladder design, the added high pass functions, the contour generator (envelope) for the filter, external CV modulation, internal modulation, audio rate modulation to make formant/vocal/vowel like sounds, mimicking down sampling and aliasing for new top end harmonics, self oscillation, driving the mixer into the filter, the feedback path around the filter, and making percussion sounds from kicks to alien toms!