Use as a “regular” VCA
To use Persephone as a common-or-garden VCA, with minimal distortion, we suggest the
following:
–
Set Pre to 0, and Post to 10.
–
Disable Asymmetry.
–
Adjust Bias until the sound is just cut of with no CV applied.
–
Apply your CV. Set the CV attenuator to 10, and then lower the attenuator until the sound
follows the envelope shape faithfully.
Zero-cross detection
To illustrate the value of the zero-cross feature, consider the following, in which an envelope
with a very fast attack is being applied to a fairly low frequency sine wave:
The yellow trace is the CV input; the magenta is the CV output. The green trace shows the
module's audio output. In this image, the zero-cross feature is not enabled. Notice how the audio
waveform rises extremely abruptly as the envelope opens. This would be audible as a nasty
click. Worse, as the relative timings of the envelope and the sine wave change from note to note,
the click will come and go randomly.
Now let's enable the zero-cross detection:
