Alesis Fusion Tutorial page 23

ALESIS FUSION
We can also apply these varying voltages to pan position:
Centre Right
+2V
0V
-2V
But what of other controllers?
Well, given that we now know the basic rule about how voltage can control pitch, timbre,
amplitude, waveshape and panning (and other things as we shall see), we can devise other
controllers.
What if, for example, we place a wheel next to the keyboard - when we move it forward, the
voltage it sends to the oscillators is higher and when we move the wheel down, the voltage is
lower. You've just added a pitch bend wheel! We can do the same with joysticks, rotary and
other controls
What if we make a keyboard that, when you hit it harder, it generates a higher voltage and we
route that to the filter and amplifier?
We have a velocity sensitive keyboard that can control tone and amplitude according to how
hard or softly we play it! Of course, because the velocity voltage can be routed anywhere you
want, velocity could also be used to control pulse width, panning, even pitch.
This is the principle of voltage control and it was the backbone of analog synthesis for decades
until it was replaced by the microprocessor after which such tasks were performed not using
varying voltages but with digital data streams.
And this is why voltage control is described here. Even though it has been many years since
we used true voltage control
almost identical to the way that true voltage control worked on the original analog synths but
somehow, it is easier to understand the concept of pitch rising as a voltage rises rather than the
more abstract passage of 01101010001010 accumulating in a software multiplier! Take the
time to re-read this if you are unsure about the principles involved because they are the key to
understanding controllers and modulation which lie at the heart of analog synthesis.
With that under our belt, we can look at the actual controllers themselves.
7 Other than in specialised analogue modular synths being made today, of course, from
manufacturers such as Doepfer, Analogue Systems, Synthesisers.com and others.
Controllers
Centre Left Centre Right Centre
7
, the way that digital control is implemented in modern synths is
ANALOG SYNTHESIS TUTORIAL
Centre Left Centre Right Centre Left
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