16
Studio Electronics Boomstar Quick Start Manual
Panels
initial rise and fall of the attack and decay times to the sustain level, the release time takes effect after the sustain
level segment, when the played key or note is lifted. The frequency at which the sustain level is set, falls to the initial
filter cutoff frequency level at the rate set by the release time.
5.2.8 ENV 2 - Envelope 2
A
word about the Amplifier Envelope:
The volume of the audio signal, which passes through the VCA envelope, is contoured by the
ENV 2
controls. Each
time a key is pressed, the envelope or contour generator attached to the amplifier is actuated, and sends a control
signal to the amplifier. Like the filter envelope control signal, the VCA envelope control signal is composed of the
same four segments: initial rise, decay, sustain level, and release time. The volume of the note is shaped according
to the settings of the envelope controls. These four parameters are shown below.
The
ATTACK
knob sets the attack time. The attack time determines the duration of the initial rise in volume to a peak.
Notice the sound take on different qualities as you increase from a short sharp attack to a long slow crescendo.
Switching
INVERT
on reverses the behaviour of the normal ADSR envelope... Wait this sound familiar: ENV 2’s invert
functions is an exact clone (what used to be called a carbon copy) of ENV 1’s. The
LFO TRIG
(Low Frequency Oscillator
Trigger) switch selection, triggers the “gate” of ENV 2: the amplifier envelope.
The
DECAY
knob sets the decay time. The decay time determines the duration of the drop in volume from the initial
peak to the sustain level. Shorter decay times will produce more percussive/snappy sounds, longer times open up
and stretch out the sound. Switching
SINGLE TRIG
(single trigger) on allows for the continuation of the decay cycle
through a legato, or multi-note phrase. Switching
MULTI TRIG
(multiple trigger) on forces the attack and decay cycle of
both
ENV 1
and
ENV 2
to restart with every key press, or note on command.
The
SUSTAIN
knob sets the sustain level. The sustain level determines the volume level at which the envelope contour
levels off after the attack and decay. Set at “0,” no sustain level is heard. Set at “5,” the contour diminishes to a low
volume. Set at “10,” no drop in volume is heard after the initial peak is reached. With
DRONE
on, the last note received
by the Boomstar—MIDI or CV—is indefinitely sustained. The
MASTER
switch setting makes
ENV 2
modulate both the
filter and the amplifier.
ENV 1
’s controls are still active in that they can still modulate the frequency of Oscillator 2
and the pulse width of Oscillator 1. To restate for clarity’s sake:
ENV 2
’s knobs assume the Boomstar’s Attack, Decay,
Sustain, and Release values for both filter and amplifier: a tidy and retro sound styling that brings to mind certain
beloved analog keyboards from the ‘80s.
The
RELEASE
knob sets the release time. The release allows the sound to fade out at the time set, rather than
immediately upon release of a note or key. This “final decay” takes effect after the sustain level segment of the
envelope and “does work” after the playing, triggering, or sequencing is done.
