Important Points - Yamaha CS-15 Owner's Manual

applications
IMPORTANT
POINTS
1.
HOW
TO SELECT
WAVEFORMS
Waveforms
have
to
be considered
first
of
all
when
creating tones.
The
CS-15
provides three
kinds of
waves,
A
(triangle), [\
(sawtooth),
and
f~L(square),
as well
as noise.
Let us explain
the particular use
of
each.
The most fundamental
is
the
N. (sawtooth
wave),
which
has a tonal quality
(harmonic components)
-0
M
LFO
MOD
''"
PW
Spectrum
of triangle
wave
OdH
-10
-?0
30
d0
-50
-60
Frequency
(F)
Amplitude
(A)
Amplitude
Period
-
Time
3F
5F
7F
9F
11F
A A
A A A
9
25
49
81 121
Spectrum
of
sawtooth wave
OdB
-10
-20
-30
---Time
Period
Frequency
(F) 2f
3F
4F5F6F
iof
Amplitude (A)|
4 $
ii~-$>
Spectrum
of
symmetrical
square
wave
Period
OclLi
-10
?Q
Frequency
(F)
Amplitude (A)
Amplitudef
ri_h-
-Time
3F
A
3
5F
A
5
7F 9F
IIF
AAA
7
9
II
similar to those
of trumpet and
violin.
As one
can
change tones with
pulse
width (PW),
this
wave has
a
variety
of
uses.
For example,
if
PW
is
50%,
its
tone
resembles that
of
the
clarinet. If
PW
is
60
to
70%,
the tone resembles
that
of
a
saxophone.
If
PW
is
80
to
90%,
the
tones resemble those of an oboe and
bassoon.
The
pulse
waves
are suitable for creasing the
tones of reed instruments.
Though
the
triangle
wave
has
harmonic components
similar to that
of
a
50%
pulse
wave,
it
sounds
soft
because of
their
low
level.
2.
HOW
TO SELECT THE
FILTER
The
function of
the
filter
is
to
cut the
harmonics
of
the
sound
source
waveforms
to
approximate them
to the desired tones.
The
filter
of CS-15
provides
a
selection of three
modes,
HPF
(high-pass
filter),
BPF
(band-pass
filter),
and
LPF
(low-pass
filter).
Q
fc=i
lfo
mo
EG
DEPTH
The
HPF
removes harmonics lower
than the
cut-
off frequency but
leaves
high harmonics.
The
BPF
removes
high and low harmonics but
leaves
harmonics
within
the
range of
the cut-off frequencies.
The LPF
removes
high harmonics but
leaves
harmonics lower
than
the cut-off
frequency.
When
producing
instru-
ment
sounds, the
LPF
is
used
in
most
cases.
The
reason for
this
is
that the
LPF
can control high
har-
monics components
while
retaining the
fundamentals.
When
lighter tones are desired or
low components
are
to be cut, the
BPF
is
used.
The
HPF
is
used
when
tones
like
those of cymbals
are
made
or effect
sounds
are
produced.
Let us
explain general procedures of operations
while taking the
example
of producing trumpet
sounds.
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