Access virus os4 Benutzerhandbuch
ACCESS VIRUS OS4
35
The First Oscillator
pots labeled SHAPE and WAVE SEL/
PW. These enable you determine
the waveshape and consequently
the tonal spectrum of Oscillator 1.
PW. These enable you determine
the waveshape and consequently
the tonal spectrum of Oscillator 1.
In the sound program, SHAPE is
preset to the center position (12
o’clock), which is equivalent to a
value of 64. On the pot, this posi-
tion is identified via a graphic
depiction of a sawtooth wave. You
can definitely see why this wave-
shape bears the name “sawtooth.”
Press and hold a key and slowly
turn the pot clockwise. You should
be able to hear how the tone
becomes increasingly more hol-
preset to the center position (12
o’clock), which is equivalent to a
value of 64. On the pot, this posi-
tion is identified via a graphic
depiction of a sawtooth wave. You
can definitely see why this wave-
shape bears the name “sawtooth.”
Press and hold a key and slowly
turn the pot clockwise. You should
be able to hear how the tone
becomes increasingly more hol-
low-sounding. You might say this
effect thins the sound out, but in
any case, the entire tonal spectrum
is affected by an equal measure,
which is an audio result filters are
unable to achieve.
effect thins the sound out, but in
any case, the entire tonal spectrum
is affected by an equal measure,
which is an audio result filters are
unable to achieve.
The waveshape that is audible
when you turn the SHAPE pot to
the far right is a so-called pulse
wave. The graphical representation
of this waveshape on the control
panel gives you a good idea of its
appearance. It is unique because
the duration of the negative pulse
is equal to the duration of the pos-
itive pulse: It has a so-called pulse
width of 50%. The tone of a pulse
wave is different to that of a saw-
tooth wave because it does not
contain all overtones in the natural
overtone scale, only the odd-num-
bered tones, i.e. the first (the root
note that determines the pitch),
third, fifth, and so forth. By turning
the SHAPE pot from the sawtooth
control range towards the pulse
control range, you are actually dial-
ing every other overtone out of the
mix, which explains why the sound
becomes thinner.
when you turn the SHAPE pot to
the far right is a so-called pulse
wave. The graphical representation
of this waveshape on the control
panel gives you a good idea of its
appearance. It is unique because
the duration of the negative pulse
is equal to the duration of the pos-
itive pulse: It has a so-called pulse
width of 50%. The tone of a pulse
wave is different to that of a saw-
tooth wave because it does not
contain all overtones in the natural
overtone scale, only the odd-num-
bered tones, i.e. the first (the root
note that determines the pitch),
third, fifth, and so forth. By turning
the SHAPE pot from the sawtooth
control range towards the pulse
control range, you are actually dial-
ing every other overtone out of the
mix, which explains why the sound
becomes thinner.