The First Oscillator - Access Virus Rack User Manual

34 CHAPTER 4
Introduction

THE FIRST OSCILLATOR

To this point, we have turned our atten-
tion exclusively to sound-shaping func-
tions and have always started with the
same basic material: a so-called saw-
tooth wave. This waveshape is especially
well-suited as a neutral starting point as
it contains all of the so-called natural
scale of overtones, which give the filter
plenty of quality material to work with.
The filters, with the exception of a notch
filter or band stop (BS), trim the far
reaches of the tonal spectrum, so for
instance a signal sounds muddier after it
has been routed through a low pass fil-
ter. You can well imagine that this type
of sound modification is substantial but
insufficient for shaping more subtle dif-
ferences in tone. For instance the tone of
a trumpet differs significantly from that
of a saxophone even though no one
would seriously claim that either of the
instruments has a muddier tone than the
other.
What you need is a sound-shaping
option for the portion of a signal that a
filter allows to pass. And of course you
also need a tool for determining the
pitch of a signal. In synthesizers, both of
these tasks are executed by oscillators.
They oscillate at a variable pitch that can
be modulated and they also generate
different waveshapes which give the fil-
ters a wider variety of material to work
with.
The Virus is equipped with two main
oscillators and a so-called suboscillator.
We will first take a look at Oscillator 1,
which is the oscillator you have already
heard in action during your experiments
thus far.
Dial in the same basic sound that you
started with at the very beginning (A127
- START -). To this end, first press the SIN-
GLE button in order to return to Play
mode from the selected parameter sec-
tion. In Play mode, you can switch
sounds via the VALUE buttons.