Low Frequency Oscillators - Sequential Prophet Rev 2 User Manual

AUXILIARY ENVELOPE
DESTINATION ENV AMOUNT VELOCITY DELAY
ATTACK DECAY SUSTAIN RELEASE
The Auxiliary Envelope
—Selects a modulation destination for the Auxiliary
Destination: Various
Envelope. See "Appendix B:
Modulation Destinations" on page 73 for a list of possible destinations.
—Sets the amount of modulation from the envelope
Env Amount: -127...127
to the chosen destination. The modulation amount can be positive or negative,
allowing for inverted envelope control.
—This enables keyboard velocity to modulate the Enve-
Velocity: 0...127
lope Amount. It doesn't enable keyboard velocity to directly control the
modulation. To do this, see the user tip that follows
To create a program in which velocity controls modulation amount, turn
down and turn
envelope amount velocity amount
—Sets a delay between the time the envelope is triggered
Delay: 0...127
(note on) and when the attack portion actually begins.
—Sets the attack time of the envelope. The higher the
Attack: 0...127
setting, the slower the attack time and the longer it takes for a sound to
reach its full volume. Pads typically have softer (longer) attacks. Percus-
sive sounds have sharper (shorter) attacks.
—Sets the decay time of the envelope. After a sound
Decay: 0...127
reaches its full volume at its attack stage,
sound transitions to the level set with the
setting, the longer the decay. Percussive sounds, such as synth bass, typi-
cally have shorter decays.
30 Auxiliary Envelope
aux
up.
controls how quickly the
decay
control. The higher the
sustain
Sequential
—Sets the sustain level of the envelope. The higher the
Sustain: 0...127
setting, the louder the sustained portion of the sound will be. The sound
will stay at this level for as long as a note is held on the keyboard.
—Sets the release time of the envelope. This controls
Release: 0...127
how quickly a sound dies out after a note is released.

Low Frequency Oscillators

The four LFOs are special-purpose oscillators that produce a frequency
that is typically below the range of human hearing (although these can
actually extend into the audio range if set to their maximum frequency).
The LFOs are typically used for periodic modulation such as vibrato
(periodic pitch modulation) and tremolo (periodic amplitude modula-
tion). They can also be used as modulation sources for any of the many
modulatable parameters in the Prophet Rev2.
The LFOs produce a variety of waveshapes, including triangle, sawtooth,
reverse sawtooth, square, and random. Though most often used for low-
frequency modulation, the Prophet Rev2 LFOs can actually function at
speeds that extend into the audible range for extreme effects.
LOW FREQUENCY OSCILLATORS
Triangle
1
Sawtooth
Rev Saw
Square
2
SHAPE
Random FREQUENCY CLK SYNC
3
4
DESTINATION AMOUNT KEY SYNC
The Low Frequency Oscillators
Triangle and Random waves are bipolar. That is, their waveshape is posi-
tive for half of their cycle and negative for the other half. In the case of the
triangle wave, this makes it possible to generate a natural-sounding vibrato
that goes alternately sharp and flat in equal amounts on either side of a center
frequency. Random, also known as "sample and hold," generates a series
of random values, each held for the duration of one cycle
Prophet Rev2 User's Guide Low Frequency Oscillators 31