Kurzweil K2600 Musician's Manual page 547

Range of Values
for Input a a a a
From To
0 .0625
.0625 .125
.125 .1875
.1875 .25
.25 .3125
.3125 .375
.375 .4375
.4375 .5
.5 .5625
.5625 .625
.625 .6875
.6875 .75
.75 .8125
.8125 .875
.875 .9375
.9375 1
Table 17-1 Quantizing b to a
As an example, consider the FUN we set up at the beginning of the previous section: the Mod
Wheel was assigned as Input a, and the data slider as Input b. The FUN was assigned as Src1 on
the PITCH page, and the depth of Src1 was set to 1200 cents. If you push the Mod Wheel all the
way up, the value of Input a will be +1. This will set the number of steps at 8, since the data
slider sends a unipolar control signal. With your MIDI controllerÕs data slider at minimum, play
and sustain a note. Then move the data slider slowly up. The pitch of the note will jump up an
octave in 8 steps as you move the data slider all the way up.
If the value of Input a is negative, itÕs multiplied by -1, so its value always falls within the ranges
above. When Input b is bipolar and the resulting number of steps is an odd number, the steps
are centered around a value of 0Ñthat is, the center step is equivalent to no effect from Input b.
When the number of steps is even, a value of zero is not included in the steps. This is also true
for the values marked by an asterisk when Input b is unipolar.
lowpass (f = a, b)
This equation might be called a lag equation. Its effect is to introduce a delay in the K2600Õs
response to changes in the value of Input b. It works by Þltering (reducing) higher values of
Input b. The value of Input a determines the degree to which the values of Input b are Þltered.
Low values for Input a will induce a long lag when the value of Input b changes. High values
will shorten the lag. When Input b remains constant at a high level, low values of Input a will
cause the FUN to sweep up slowly from 0 to the value of Input b. Higher values for Input a will
cause the FUN to sweep more rapidly.
The four graphs below show the effect of different values for Input a on the change of Input b. In
each graph, the value of Input b jumps from 0 to +1. In graph 1, the value of Input a is +1. Each
Number of Steps as Input b b b b
Moves from Min to Max
When Input B is Bipolar
1 (no effect)
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
When Input B is Unipolar)
1
1*
2
2*
3
3*
4
4*
5
5*
6
6*
7
7*
8
8*
FUNS
The FUN Equations
17-7