Kurzweil K2600 - MUSICIANS GUIDE REV A PART NUMBER 910330 CHAP 17 - Boolean FUN Equations; Sawtooth LFO FUN Equations

17-14
FUNS
The FUN Equations
warp8(a, b)
This relatively simple equation is a x b x 8. If the result is beyond the range of -1 to +1, it wraps
around from +1 to -1 (or vice versa), until itÕs within the allowable range. The table below shows
some examples of how this works.
Boolean FUN Equations
a AND b
The values of Inputs a and b are interpreted as logical quantitiesÑtheyÕre considered TRUE if
theyÕre greater than +.5, and FALSE otherwise. This turns the FUN into an on/off switch. In the
model we set up in the previous section, FUN1 was assigned to control Src1 on the PITCH page,
and Src1Õs depth was set to 1200 cents. With this equation, both Input a (the Mod Wheel in this
case) and Input b (the data slider in this case) would have to be more than halfway up for the
FUN to switch on. The pitch would jump 1200 cents as soon as both control sources moved
above their halfway points. As soon as one of them moved below its halfway point, the pitch
would jump back to its original level.
This equation can be used to trigger ASRs, or as a layer enable control, or for any control source
that toggles on and off. If you set one of the inputs to an LFO, the FUN would switch on and off
every time the LFOÕs signal went above +.5 (as long as the other input was also above +.5).
a OR b
This equation is very similar to a AND b. The only difference is that the FUN will switch on
when the value of either Input a or Input b moves above +.5.
Sawtooth LFO FUN Equations
The next six equations case the FUN to generate a sawtooth LFO as its output signal. Each
performs a different operation on the values of Inputs a and b, and the resulting value is
multiplied by 25. The result determines the frequency of the LFO. If the value is a positive
number, the LFO has a rising sawtooth shape. If the value is negative, the LFO has a falling
sawtooth shape. When the resulting values are large (above 10 or so), the output waveform is
not a pure sawtooth; a bit of distortion occurs.
a x b x 8 =
Final
Output
Value
-7.4 .4
-4.2 -.2
-1.8 .8
-.6 -.6
.4 .4
1.2 -.2
2.6 .6
5.4 -.4
Table 17-2 warp8(a, b)