User Manual

22 Filter Dave Smith Instruments
Filter
The Filter takes the basic, raw sound of the oscillators and noise genera-
tor and subtracts frequencies, changing the harmonic content and char-
acter of their sound. This change can be varied over time using the Filter
Envelope to produce more dynamic, animated timbres.
The Prophet Rev2’s lter is a classic, resonant low-pass Curtis lter that is
switchable between 2-pole operation (12 dB per octave) and 4-pole operation
(24 dB per octave). The 4-pole lter can self-oscillate when
resonance is
set to its maximum.
CUTOFF RESONANCE ENV AMOUNT VELOCITY KEY AMOUNT AUDIO MOD
4 POLE DELAY ATTACK DECAY SUSTAIN RELEASE
LOW-PASS FILTER
The Prophet Rev2 Filter
Cutoff: 0...164—Sets the lter’s cutoff frequency. Frequencies are
reduced from the top down, cutting the high frequencies and passing the
low frequencies, hence the name “low-pass.”
Resonance: 0...127—Emphasizes a narrow band of frequencies around
the cutoff frequency. High levels of resonance can cause the lter to self-
oscillate in 4-pole mode and generate its own pitch.
High levels of resonance can sometimes cause the Prophet Rev2 outputs to
clip. Monitor your outputs carefully to ensure optimal, clean signal levels. If you experi-
ence signal clipping, try reducing the levels of the resonance parameter in the lter.
Env Amount: -127...127—Sets the amount of modulation from the lter
envelope to the lter’s cutoff frequency. Any setting above zero means
that each time you strike a key, the lter envelope controls how the lter
opens and closes. Higher amounts more dramatically affect the cutoff
frequency. This control is bipolar. Positive settings produce standard
behavior. Negative settings invert the envelope.