Korg PS60 Parameter Manual page 62

Program Edit
Offset
This controls the amount of offset for AMS A.
Setting Offset to +199 shifts an AMS input of –99 all the way
to +99. In conjunction with high AMS A Amount values, this
can be useful for creating clipped shapes, such as shown in
the last of the "AMS Mixer Offset examples," above.
Smoothing
This Mixer Type smooths out the AMS input, creating more
gentle transitions between values. You have separate control
of the amount of smoothing during the attack (when the sig‐
nal is increasing) and decay (when it's decreasing).
The higher the Attack and Decay settings, the more the
input will be smoothed.
Low settings provide subtle controller smoothing, creating
more gradual aftertouch, for instance. Higher settings create
auto‐fade effects, transforming a quick gesture into a longer
fade‐in and/or fade‐out event.
Smoothing can also be used to alter the shape of program‐
mable mod sources, such as LFOs and EGs. For instance,
you can turn a "blip" into a simple envelope shape, as
shown below.
AMS Mixer Smoothing examples
Original AMS A:
Smoothing with Short Attack Long Release:
AMS A Source
This selects the AMS source to be smoothed.
For a list of AMS sources, please see "Alternate Modulation
Source (AMS)" on page 121.
Attack
This controls the attack time of the smoother, or how long it
takes the smoother to reach a new, higher value.
Higher Attack settings mean longer times.
Depending on how quickly the AMS input value is chang‐
ing, high Attack settings may mean that the value is never
quite reached, as shown in "AMS Mixer Shape examples,"
above.
Decay
This controls the decay time of the smoother, or how long it
takes the smoother to reach a new, lower value.
Higher Decay settings mean longer times.
Shape
This Mixer Type adds curvature to the AMS input. This
applies deformation to the AMS input. You can use this to
customize a controller curve, such as the exponential curve
of the joystick or the logarithmic curve of velocity control. It
can also alter the shape of programmable modulation
sources, such as EGs and LFOs.
Note: Shape only affects AMS signals which already have
some amount of slope, such as EGs, triangle and sine LFOs,
and so on. It does not affect signals which only contain
abrupt transitions, such as square waves.
58
[–199...+199]
Smoothing with Long Attack
and Short Release:
[List of AMS Sources]
[00...+99]
[00...+99]
AMS A Source
This selects the AMS input source to be shaped.
For a list of AMS sources, please see "Alternate Modulation
Source (AMS)" on page 121.
Shape
This controls the amount of curvature, and whether the
curves are concave or convex. As you can see in the graphic
examples, the shape will tend to emphasize certain value
ranges, and de‐emphasize others.
For example, let's say that you are using a triangle LFO,
through Shape, to modulate filter cutoff. If Shape empha‐
sizes the high value range, the filter will spend more time at
the higher frequencies. If it emphasizes the low range, the
filter will spend more time at the lower frequencies.
Mode
This selects whether the Shape parameter will produce one
or two curves. The graphic "AMS Mixer Shape examples"
may help to visualize how this works.
Asymmetric will produce a single curve, extending from
–99 to +99.
Symmetric will produce two matching curves extending
outwards from 0 to –99 and +99, respectively.
Bipolar and Unipolar AMS sources
To understand Shape, it helps to understand the difference
between bipolar and unipolar AMS sources.
Bipolar sources can swing all the way from –99 to +99, with
0 in the middle. Most LFOs are bipolar, for instance; so is
Pitch Bend.
Generally, bipolar AMS sources will work better with the
Asymmetric mode, but Symmetric may also produce inter‐
esting results.
Unipolar sources only go from 0 to 99, with 50 in the mid‐
dle. MIDI controllers, such as JS+Y (CC#1), are all unipolar.
In practice, EGs are usually programmed to be unipolar,
even though the Filter and Pitch EGs do allow both positive
and negative levels.
With unipolar sources, it's almost always better to use the
Symmetric mode. The Asymmetric mode can cause offsets
and other strange results.
[List of AMS Sources]
[–99...+99]
[Symmetric, Asymmetric]