User's Manual

9. DISPERSION
Sometimes minor imperfections in an instrument give it soul and character. The strings of a
piano are never perfectly in tune, and the way each hammer strikes its own string is unique.
So it was with analog synthesizers. Analog components have variable tolerances, are
subject to aging, and react to ambient temperature changes. So they had to be recalibrated
from time to time to tune their oscillators, filters, envelopes and other parameters by
"tweaking" small trimpots (potentiometers) on the circuit card, or, later, by automatic
calibration circuits.
In a keyboard like the Roland Jupiter 8 (so-called because it had 8 voices), it may look like
you have two oscillators, two envelopes, and one filter; but actually there were 16 oscillators
and envelopes and 8 VCAs and filters. Theoretically, the eight voices should be identical to
each other in tuning and other parameters; in reality they had differences from each other.
Virtual instruments are digital, which can be a good thing. They don't age, drift out of tune
or fall out of calibration. But this also suppresses the small imperfections that sculpt the
character of the instrument.
So to fully capture the analog nature of the Jupiter 8, Arturia engineers added the Dispersion
controls to the JUP-8 V4 emulation. These allow you to select exactly how "analog" you want
a patch to be. You may not notice the effect right away; it can be subtle, but it can also bring
life into your sounds and make the instrument sound organic.
9.1. Dispersion modes: 1, 2, 3 and Custom
There are four green keys that select the dispersion mode. The numbered modes are factory
presets emulating a condition of the synthesizer.
Dispersion mode is saved with every preset; if you make your own Custom setting for a
preset, that will be saved with that preset only and will not be applied to other presets that
have their own Custom mode.
The DISPERSION section with the trimpot "cover" open.Dispersion preset 1 shows some
pitch variance, and low levels of pulse width, envelope, VCF cutoff and resonance, and
modulation dispersion
Arturia - User Manual Jup-8 V4 - Dispersion 76