Alesis ModFX Reference Manual page 34

3
Using the Philtre
Modulation Select Switch
The up/down rocker switch on the right side of the unit selects the
modulation source for the Philtre. The LEDs next to the switch
light up to indicate the current mode. There are five kinds of
modulation available, explained below. The rocker switch also
selects TEMPO SYNC mode, as explained earlier.
Triangle
This mode uses a triangle wave to modulate the filter effect. Use
this when you want the filter to move up and down in regular,
smooth waves.
Sample/Hold
This mode selects a sample and hold wave for the filter's
modulation. The filter's center frequency will jump randomly
around the center setting, holding a setting until it's time for the
next one. The left and right channel filter settings are randomly
set apart from each other, creating an interesting stereo effect.
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