ARP ODYSSEY - Page 18

EXPERIMENT
4.
NOISE
EXPERIMENT 5, FREQUENCY
MODULATION
Lower the blue and gt&en sliders
under
the
AUDIO
MIXER boji 5nd raise She white slider. Play a few
notes On
the
keyboard
and
list&n
to
th& sound. You
are hearing what is known as WHITE NOISE.
This
nois& contains all frec^usncifis ufi the ^udio spectrum
in
equal amaunts^
aitd is
hanuorticaUy IdentLC^ to the
noise you hear between stations on
the
FM
radio
band.
Thepe
is e
noise generator svntcb
located in the upper
left hand
Corner
of the
ODYSSEY.
Chartg^
the
position of this switch to PINK and again play a few
notes on the keyboard. Whereas WHITE NOiSE
contains equal amplitydes of each
frequency, PINK
NOISE contains equal energy
of each frequency.
Physically, this means that the higher frequencies are
presenE
at
lower volumes than
the lower frequencies.
PlMK NOISE is the most musically useful kind
of
noise because it sounds balanced to the ear, neither
too
hi9h and
hissy,
nor
coo
low and rumblmg. You
will see later
how
to use
the other functions
on ihe
ODYSSEV to turn noise into a wide range of
exciEing
sounds.
The pitch
of the Voltage Controlled
Oscillator
(VCO)
on your
ODYSSEY is
controlled
by
the
keyboard. You know this from the
previous
experirMnts and you can
also 5ee
that
the
keyboard
is
connected to the VCO on the
block
diagram, page 9. As you will now
experience, you can also change the
pitch or
frequency
of
the
VCO
hy
bringing in "control voltages"
from
o-ther devices on the ODYSSEY.
I. To
begin
experimenting with
Frequency Modulation,
again
set the controls e:cactly as
shown
in Pigure
C.
Raise the blue VCO 1 slider under the
AUDIO
MIXER.
You vjiU now hear the
sawtooth
wave again when
you play the keyboard.
Hold down a note on the
keyboand
and slowly raise
the
pink LFO oontial next to
the TRANSPOSE
ill