Envelopes - Casio CZ-1000 Operation Manual

Figures
1
to
3
showed
the kind of reading phase angle
distortion pattern that occurs
when
the
phase angle reading speed from 0
to
it
is
accelerated while the
phase
angle reading speed from
7r
to
2
7r
is
slowed down.
A
pattern such
as
this
is
created
when
the saw-tooth wave form
is
selected
with the
DCO
Wave Form
parameter.
If
a different
kind
of
wave form
is
selected with the
DCO
Wave Form
parameter, the reading phase
angle
is
distorted to that respective pattern.
The CZ-
1000 can
thus output
a
whole
variety of
wave
forms.
The
intensity
of the reading phase angle
distortion
is
controlled
by
the
DCW
envelope's
momen-
tary value,
meaning
that
it
can be
changed
over time.
If
the
DCW
envelope
is
set
as
shown
in Fig.
4,
an
undistorted cosine
wave
is
output
at
point
®
,
while
distortion
is
at
its
maximum
at
point
©
so
that a saw-tooth
wave
is
output
as
shown
in Fig.
3.
At
point
©
,
distortion
has
become
less
(meaning
the intensity of the
modulation has
decreased), so
that a
wave form
is
output
that
lies
somewhere
between
the kind
of
cosine
wave shown
in
Fig.
2 and
a
perfect
saw-tooth wave.
(Fig.
4)
Points
to
remember:
DCW
envelope
Key
ON
Key
OFF
1)
The
pattern of the reading
phase
angle
distortion
corresponds
to
the
wave form
selected with the
DCO WAVE FORM
parameter.
2)
The amount
of
reading phase angle
distortion
(in-
tensity
or depth
of
modulation)
is
determined by
the
momentary
value
of
the
DCW
envelope.
•
Envelopes
The CZ
-
1000 has independent envelope generators
for
each
of the
two
DCO/DCW/DCA
systems.
The
envelopes generated by these envelope generators
control the
changes
in pitch,
tone
color
and sound volume
over
time.
The
envelope generators of the
CZ
-
1000
let
you
set
complex
enve-
lopes with
up
to
8
steps. In
addition, the Sustain Point (which
determines
the
level at
which
a
sound
is
held as long as a key
is
being pressed)
can be
set at
will.
This
means
that
you
have
much
more
freedom than with conventional envelope generators
limited
to
ADSR
(see below), giving
you
infinite possibilities for
sound
creation.
(Fig.
1)
Fig.
1
shows an example
of
an envelope
using
all
8
steps. In this
example, there are two
attacks before
the Sustain Point as
well as a
third
attack
after releas-
ing the
keys.
This
shows
how
you even have
the pos-
sibility of setting
an
"after-envelope".
Key
ON
Key
OFF END
Step
Rn and Ln
(n
=
1 to 8)
indicate
the
rate
(speed of
level
change, "slope")
and
level (final level
reached
in
a step) respectively.
Within
a particular
envelope, the
level
Ln
is
reached
after
the slope
Rn
to
complete
step
n.
Following the
arrival at
Ln, step n
+
1
begins
(with slope Rn+i).
The
only excep-
tion
is
the step
in
which
the Sustain Point
has been
set,
which
is
step
5
in
our
example
in Fig.
1.
During
this step,
the sustain
level (the level set for
the step containing the sustain
point)
will
be
held as long as
a
key
is
being pressed, without
moving on
to
the next
step.
As soon
as the
key
is
released,
the following
envelope
step
will
commence
with the
corresponding
slope
(rate).
Fig.
1
shows an example
of
an envelope
making
use
of
all
8
steps.
Of
course,
it
is
up
to
you
how
many
steps
you want
to use.