Yamaha CS-15 Owner's Manual page 11

FUNCTIONS
VCF
The
VCF
blocks
change
the harmonic
structure of the
sound
sources
and
control the tone
coloration
via
the cut-off frequency
of the
filter,
influenced
by
the control
voltages
from
the envelope
generators,
etc.
•
When
checking the functions
of
VCF
or
making
tone
adjustments, the control of the
BRILLIANCE
block should be
set
to the
center.
E>
@
HPF/BPF/LPF
Filter selectors
These
switches
select
the types
of
filter.
HPF
:
High-Pass
Filter
Frequencies
lying
between
the cut-off
fre-
quencies
pass.
The
CUT-OFF
FREQ
knob
is
used
to
set
the
width of
the
band
being
passed. In the
L
position
we
get
a
narrow
band
width,
as
the
FREQ
knob
is
moved
toward
H
the
band of
frequencies
is
widen.
Band-Pass
Filter
Frequencies
lying
between
the cut-off
fre-
quencies
pass.
Low-Pass
Filter
Frequencies lower than
the cut-off frequen-
cy
pass.
This type of
filter
is
generally
used
in synthesizers.
BPF
LPF
Kinds
of
filters
HPF BPF LPF
/
-Pass
-
Pass
-
*
'
!
Pass- T
fc
f:'
f
:>
fc-i
)®
CUT OFF FREQ
This
knob
controls the
boundary
frequency
be-
tween
the range being passed by
the
filter
and
the
range being
cut, called cut-off frequency.
The
further
towards
H
side
it is
turned, the higher the cut-off
frequency becomes. This
part
is
very important
in
producing
basic tone
qualities
from
a
synthesizer.
Cutoff
Frequency
LPF
>=>
-^harmonics
Pass*
--
fc
-Cut
F:
fundamental
fc;
Cutoff Frequency
•
The
cut-off
frequency
can be
also
controlled
by
the control
in
the
BRILLIANCE
block.
•
If
the
cut-off frequency
is
set
so
low
that
all
the
harmonics
as well as
the fundamental
are
cut,
no sound
is
produced. This condition
exists
when
the
CUT OFF FREQ
knob
is
turned fully
to
L with the
filter
selector
set
to
LPF.
\>
®
RESONANCE
If the
RESONANCE
knobs
are turned towards H,
the
harmonics
in the
neighborhood
of
the cut-off
frequency
are
emphasized
to
make
tones
more
ac-
centuated.
Resonance
This portion
emphasized.
is
es
:
H n
c f
\
harmonics
\
M
-
R
es
:
L
1
F
:
ha
rmo
nics
f
c
F
:
ha
rmo
Tics
I
F:
Fundamental
<D