The Second Oscillator - Access Virus Rack User Manual

THE SECOND OSCILLATOR

As we mentioned previously, in addition
to the other sound sources, the Virus is
equipped with a second oscillator which
has more sound-shaping options than
Oscillator 1.
Dial in the basic sound program that you
had at the very beginning; change the
amplifier envelope to suit your taste. In
the sound program, the OSC BAL (Oscil-
lator Balance) parameter in the OSCILLA-
TOR menu is preset to the far left. In
order to hear Oscillator 2 in action,
rotate the Value encoder to the right.
Towards the center position (12 o'clock)
you will hear how the tone is modified
and as you rotate the encoder further to
the right, how the intensity of this modi-
fication is reduced. This effect is known
as the comb filtering effect. It occurs
when two signals with the same fre-
quency but different phase lengths are
mixed. Press the same key on your key-
board several times with the OSC BAL set
to the center position (12 o'clock). You
should notice that each note has a
slightly different tone. The oscillators are
the source of this effect. The oscillators
of the Virus oscillate freely, consequently
every time you play a note, the phase
constellation between the two oscilla-
tors is different. For now, leave OSC BAL
at the center position (12 o'clock).
You are already familiar with Oscillator
1's SHAPE and WAVE SEL/PW parame-
ters. These functions are identical for
Oscillator 2, so we won't go into detail
on them again.
Locate the encoder labeled DETUNE and
slowly rotate it to the right from the far
left position (which is preset in the sound
program). You can hear the tone start to
waver and as you turn the encoder fur-
ther to the right, how this vibrato effect
increases until Oscillator 2 sounds dis-
tinctly out of tune with Oscillator 1. This
wavering or vibrato-type effect has a
popular traditional in synthesizers. It is
used to achieve chorus effects, create
sounds reminiscent of stringed instru-
ments/ string sections or simply beef up
the sound.
The SEMITONE encoder enables you to
transpose Oscillator 2 by plus/minus four
octaves in semitone steps while Oscilla-
tor 1 maintains the pitch. This feature is
especially interesting when used in con-
junction with two other oscillator func-
tions: synchronization and frequency
modulation.
Locate and activate the SYNC parameter
in the OSCILLATOR 2 menu (Sync On).
The synchronization function forces
Oscillator 2 to restart its wave cycle at
the same time as Oscillator 1 waveshape
starts its cycle. The initial effect of this
ACCESS VIRUS RACK 37
The Second Oscillator