Korg modvawe Owner's Manual page 85

Modulation Processors
Input
[List of Modulation Sources]
This selects the input for the Mod Processor.
Mode
[Symmetric, Asymmetric]
Asymmetric produces a single curve, extending from –100 to +100.
Symmetric produces two matching curves extending outwards from 0 to –100 and +100, respectively.
Curve and Mode
Bipolar Triangle Wave
Asymmetric
+100
0
–100
Symmetric
+100
0
–100
Curve
[–100.00%...+100.00%]
This controls the amount of curvature, and whether the curves are concave or convex.
As you can see in the graphic examples, the curve will emphasize certain value ranges, and deemphasize others. For
example, let's say that you are using a triangle LFO, through Curve, to modulate filter cutoff. If Curve emphasizes high
values, the filter will spend more time at higher frequencies. If it emphasizes low values, the filter will spend more time
at lower frequencies.
Mode Input
Symmetric Unipolar
Bipolar
Asymmetric Unipolar
Bipolar
Bipolar and Unipolar modulation sources
To understand Curve, it helps to understand the difference between bipolar and unipolar modulation sources.
Bipolar sources can swing all the way from –100 to +100, with 0 in the middle. Most LFOs are bipolar, for instance; so
is Pitch Bend. Generally, bipolar modulation sources will work better with the Asymmetric mode, but Symmetric may
also produce interesting results.
Unipolar sources only go from 0 to 100, with 50 in the middle. Often, MIDI controllers are unipolar (though you can
also select bipolar versions). Envelopes are usually programmed to be unipolar, even though the Filter and Osc 1/2
Envelopes allow negative levels.
With unipolar sources, it's almost always better to use the Symmetric mode; Asymmetric can cause offsets and other
strange results.
+100
Curve
Positive (+) emphasizes upper value range
Negative (-) emphasizes lower value range
Positive (+) emphasizes both upper and lower value ranges,
and deemphasizes the center
Negative (–) emphasizes center value range, around 0
Positive (+) emphasizes extreme upper range, with offset
Negative (–) emphasizes extreme lower range, with offset
Positive (+) emphasizes upper value range
Negative (–) emphasizes lower value range
80
Unipolar Triangle Wave
Asymmetric
(not recommended)
0
–100
Curve = 0 (original waveform)
Curve = +100
Curve = -100
Result
Symmetric