LFO is like an LFO on a synth - you can assign one of four waveforms (Tri, Sqr, Saw, Sample & Hold) to sweep the filter. In the MANUAL mode you control the filter from the extra voice/drawbars effects amount pots, using the knob like a cutoff filter pot on a synth. The nice thing is that you can adjust the sensitivity, resonance, waveform, rate and center frequency, and save those parameters in a patch (as well as the control source).