Dave Smith Instruments MOPHO SE - Manual (Page 23)

17
Filter
Mopho features a selectable 2- or 4-pole, low-pass filter.
4-Pole —Selects the filter configuration. When lighted, the filter is in 4-pole
mode. A 4-pole, low-pass filter rolls off frequencies above the cutoff frequency
at a slope of 24dB/octave. When the light is off, the filter is in 2-pole mode and
has a slope of 12dB/octave and a more gradual rolloff of the higher frequencies.
Frequency: 0...164 —Sets the base filter cutoff frequency over more than 13
octaves. This control steps in semitones when turned slowly, but smoothly
controls the filter without steps when turned at a faster rate.
Resonance: 0...127 —Emphasizes a narrow band of frequencies around the
cutoff frequency. In 4-pole mode, high levels of resonance can cause the filter to
self oscillate. In 2-pole mode, resonance is much more subtle.
Audio Mod: 0...127
—Controls the amount of audio from oscillator 1 used to
modulate the filter cutoff frequency. For filter-only audio, set the oscillator Mix
to 127, oscillator 2 Shape to Off, and oscillator 1 Shape to the desired
waveshape. This is useful for bell-like FM sounds. A wide range of sounds can
also be made using Audio Mod with the oscillators routed normally through the
filter.
Key Amount: 0...127 —Sets the amount of modulation from the keyboard to the
filter cutoff. A setting of 64 will step the filter in one semitone increments for
each note, 32 would be quartertones, and so on.