Pd (Phase Distortiom) Socjnd Source - Casio CZ-3000 Operation Manual

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or
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will respectively
lower or
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tone
steps.
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tnitial
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G^-A^-A*-B
b
+-B*-C-*C
l
-*D-^E
l
-
+
E->
F—
F
SOLO
SOLO
key
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Volume
SOLO
key
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Volume
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<Z)
KEY
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KCV ON
CD
KEY ON
Note©
remains even
at
KEY
ON®.
(Illustration
shows
a non-sustained
tone.)
PD
(PHASE DISTORTION)
SOUND
SOURCE
The
CZ-3000 employs
a
unique,
CASIO
developed
PD
(Phase
Distortion)
sound
source
system. This system
is
capable
of
producing
a variety
of
wave forms
by
distorting the read
phase
angles
of sine
and
cosine waves
that
are Written
in
ROM, The
pattern
ol
the read
phase angle
distortion
is
determined by
the
specification of the
DCO
(VCO
of analog
syn-
thesizer)
WAVE
FORM.
The
magnitude
(modulation depth)
of the read angle
distortion
corresponds
to the
momentary
value
of the
DCW
(VCF
of
analog
synthesizer) envelope.
(Fig.
1)
Phase
angle
Waveform
Polarity
(
+ /-) cos?
reversed
for
sake
of
Fig,
1
illustrates
output of a
no n-
distorted cosine
wave when
a
co-
sine
wave
in
ROM
is
read with
a
linear
phase
angle.
The
phase
angle
is
read
at a
cofisLmil
speed
from
through
2ir.
What
would happen
if
we
in-
crease the phase
angle read
speed from
through t and
decrease
it
from
ir
through 2t?
<Fig.
2)
As shown
in Fig.
2,
the
phase
angle read
is
distorted rather
than
linear,
and
the output
co-
sine
wave
takes
on what
is
close
to
a saw-tooth
pattern.
What
would happen
now
if
we
further increase the phase angle
read speed from through
tt
and decrease
it
from x through
2t?
<Fig.
3)
Fig.
3 shows
that
the output
co-
sine
wave
is
almost
a perfect
saw-tooth
pattern.
PART
1
NORMAL MODE
13