Casio CZ-1000 User Manual

How
to
Create
Sounds
with the
CZ-1000
•
PD (Phase
Distortion)
sound
source
The
CZ-
1000
uses the
unique
PD (Phase
Distortion)
sound
source
system developed by
CASIO.
As
the words
"phase
distortion"
indicate, this
system
distorts
the phase
angle
of
a
sine
wave
or
cosine
wave
written
into
a
ROM
when read,
thus
creating a variety
of
wave forms.
The
pattern of
the
distorted
reading phase
angle
determines
the
DCO
(corresponds
to
the VCO
in
an
analog
syn-
thesizer)
wave
form. The
amount
of
distortion
of the
reading
phase
angle
(depth of
modulation)
is
determined by
the
momentary
value
of the
DCW
envelope
(which
corresponds to
the
VCF of
an
analog
synthesizer).
(Fig.
l)
Fig.
1
shows what
happens
when
the
phase
angle
of
the
cosine
wave
written
into
the
ROM
is
read in
linear
form—
the
cosine
wave
is
output
as it
is.
The
phase
angle
is
read at a
fixed
speed,
taking
on
values
from
0 to
2 x.
Next, let
us
see
what
happens
when the
reading
speed
from
0 to 7r
is
speeded up
while
the
reading
speed
from
x
to 2 x
is
slowed
down.
(To
make the
explanation
easier to
understand,
the
polarity
of
the
cosine wave
cos
0
has
been
inverted.)
(Fig.
2)
As
shown
in Fig.
2,
the
reading of the
phase
angle
is
now
no
longer linear but
distorted,
while the out-
put
cosine wave has
become
similar to a
saw-tooth
wave.
What
happened if
we
then
make the
reading
speed
from 0 to x
faster
than before and
further
slow down
the
reading
speed
from
x
to 2 x?
As you
can
see
in Fig.
3,
the
output
cosine
wave
is
now
an
almost
perfect
saw-tooth
wave.
This
PD
sound
source
system can
thus
easily
output
all kinds
of
wave
forms
other
than
a
cosine
wave by
simply
distorting
the
reading
phase
angle
of a
cosine
wave
(or
sine
wave)
stored
in a
ROM.
This
unique
Phase
Distortion
system,
which
can
modulate
cosine
waves,
thus
proves
to
be a
truly
revolutionary
sound
source.

Casio CZ-1000 Specifications

General

Brand	Casio
Model	CZ-1000
Category	Synthesizer
Language	English