ALESIS QS8.1 - Manual (Page 162)

Part 8: Editing Programs
150 QS7.1/QS8.1 Reference Manual
T RACKING G ENERATOR
The Tracking Generator function (press [9]) is used to scale a modulation source. For
example, normally you could modulate the Amp (volume) of a sound using velocity;
the harder you play, the louder the sound gets. The amount of change in volume is
equal to the change in velocity; this is called linear control. If instead, however, you
set the Tracking Generator’s input to “velocity”, and then routed the Tracking
Generator to the Amp (using the Mod function), you can make your own customized
velocity curve!
It might be helpful to think of the Tracking Generator (TG) as a fifth page available to
the Mod function. When you choose it as your source on the first page of a Mod (let's
say button [0], or Mod 1), you then need to go select the TG's input on button [9],
page 1. In effect, the TG's input is its "Mod source", and the TG itself becomes a sort
of "Mod destination". Modulation input is basically filtered through the TG before it
reaches the actual Mod destination on page 2 of Mod 1.
The Tracking Generator divides the range of the input into 11 points (0–10), each of
which can be set between 0 and 100. If you boost the value of one of the lower points,
you make the input more sensitive in its lower register. By creating a non-linear
curve using the velocity example above, you can scale the velocity’s control over the
sound’s volume just the way you want.
When selecting the Tracking Generator as a modulation source in the Mod Function,
two choices will be available (TRACKGEN and STEPTRAK). When “TRACKGEN” is
selected as the modulation source, the Tracking Generator functions normally,
scaling its input as determined by its parameter settings.
When “STEPTRAK” is selected as a modulation source, the Tracking Generator’s
output will be stepped, or interpolated. This means that instead of scaling the input
in a linear fashion from point to point, the input is kept at each point’s value setting
until it goes beyond the following point’s value setting, at which point it jumps to
that setting. This feature is very useful in creating “mini-sequences” if the
modulation destination is set to “Pitch” and the Tracking Generator’s input is an LFO
using an “Up Sawtooth” as its waveform. The Z1 HipHop and Z2 EuroDance
QCards contain many examples of this extremely cool usage of the Tracking
Generator.