23
Prophet-6 Operation Manual
Filter Envelope
Attack:
Sets the attack time of the envelope. The higher the setting, the
slower the attack time and the longer it takes for the filter(s) to open to
the level set with the filter
cutoff
knob. Percussive sounds typically have
sharp (short) attacks.
Decay:
Sets the decay time of the envelope. After a sound reaches the
filter frequency set at its attack stage,
decay
controls how quickly the
filter then transitions to the cutoff frequency set with the
sustain
knob.
The higher the setting, the longer the decay. Percussive sounds, such as
synth bass, typically have shorter decays (and a generous amount of low-
pass filter resonance).
Sustain:
Sets the filter cutoff frequency for the sustained portion of the
sound. The sound will stay at this filter frequency for as long as a note is
held on the keyboard.
Release:
Sets the release time of the envelope. This controls how
quickly the filter closes after a note is released.
The description of envelope behavior above is true when the
envelope
amount
parameter is set to a positive value. But since this control is actually bi-polar, it is
possible to set a negative amount of modulation. In this case, the envelopes are
inverted and their behavior changes. The best way to get a feel for the difference is to
experiment with both positive and negative settings of the
envelope
amount
parameter.
The cutoff frequency setting may limit the effect of the envelope on the filter. For
example, on the low-pass filter, if
cutoff
is at its highest setting, a positive envelope
amount will have no effect on the filter since the filter is already completely open.
Changing the Filter Envelope’s Response Curve
By default, the envelopes of all synthesizers are designed to have certain
type of response curve that is largely dependent on the preference of the
designer. In most cases, this can’t be changed. The current preference is
that the faster or snappier the envelopes, the better.
However, in the case of the Prophet-6, there is a hidden feature in the
Poly Mod section that allows you to modify the responsiveness of the
Filter Envelope’s ADSR controls. This opens up a new level of fine
adjustment of these controls that is subtle but powerful. Try it and see.
