Figure 6 shows the opposite state; the
Cycle
button is initially on, so the incoming gate signal stops
cycling for as long as the gate is high. In this case, as the pulse width of the gate signal gets wider,
there are longer pauses between groups of envelopes.
Note that the first pulse in Figure 6 does not stop the envelopes, and the three rapid pulses in Figure 5
only cause one envelope. This illustrates an important aspect of the
Shaped Dual EnvVCA
: the state
of the
Cycle
button and
Trig
jack when the switch is set to
Cycle
only matter when the envelope is
stopped (at 0V). Any combination of gates and button presses while the envelope is running have no
effect; it’s only when the envelope finishes running that the
Cycle
jack or button can make it cycle
again.
Follow Jack With Gates
Figure 7 illustrates the use of gates on the
Follow
jack. A gate signal will cause the envelope to rise as
long as the gate is high. When the gate goes low,
the envelope will fall.
The fourth gate in Figure 7 shows that if the gate is
held high while the envelope reaches its maximum,
the envelope will hold (sustain) until the gate is
released. This is an alternative way to create an
ASR envelope (Attack Sustain Release)
independent of the
Trig
switch position.
The short burst of pulses at the end illustrates how
the
Follow
jack can be utilized to create complex
envelope shapes using only a sequence of gates.
The
Follow
jack can be used with more than gates, see the next section for a detailed discussion.
Fundamentals of the Follow Jack
The
Follow
jack causes an envelope to rise or fall in order to “follow” the signal on the jack. Sending a
high voltage (5V) into the Follow jack will cause the envelope to rise. Sending a low voltage (0V) will
cause it to fall. This can be seen in Figure 7 of the previous section.
Sending voltages up to 5V, such as a waveform from an LFO or an audio signal, will have more
complex effects.
There are two basic rules that govern this jack:
Rule 1:
If the voltage on the
Follow
jack is greater than the envelope voltage, the envelope will
rise; if the voltage on the
Follow
jack is less than the envelope voltage, the envelope will fall.
That is, the envelope will always “seek” the
Follow
signal: it will go up if the
Follow
signal is higher,
and it will go down if the
Follow
signal is lower. This is where the term “follow” originates.
Rule 2
: The envelope can only rise and fall at the speed set by the
Rise/Fall
controls and CV.
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Figure 5: When Cycle button is off, high gate on Trig jack
makes envelope run (switch set to Cycle).
Figure 6: When Cycle button is on, high gate on Trig jack
makes envelope stop (switch set to Cycle).
Figure 7: Sending gates into the Follow jack. When the
input gate goes high, the envelope rises; when the input
goes low, the envelope falls.
