Yamaha CS-80 Instruction Manual page 49

A
fixed
component
of the
same
value
was then
built
45
into the instrument, creating
a
kind of internal
memory
that
is
recalled
whenever
the corresponding preset
patch
is
selected.
You
can always
duplicate
a
preset
patch by
using the
programmable
panels, as
is
suggested by some
of the patch charts included
in
this
manual.
You may
wish to do
so,
and
to
then
vary
one
or
more
controls to obtain
variations
from
the
presets.
Foot Switch
&
Foot
Controller
The Foot Switch
is
just
that— an
ON-OFF
switch
which
is
housed
in
an assembly designed
for foot
actuation.
The
switch can be used to activate the
portamento/glissando effect and/or
the sustain,
depending on
the
setting of front-panel
assignment
switches.
When
the Foot Switch
is
not plugged into
the synthesizer, the jack automatically
closes the
circuit so the unit acts
as
though the Foot Switch
were
pressed
down.
The Foot
Controller contains
more complex
circuitry,
including
a
light
and
a
photosensor. As the
pedal
is
rocked back and
forth, an aperture
varies the
amount
of
light
reaching the photosensor.
In turn, the
sensor varies
its
resistance,
and hence
varies the voltage
output from
the circuit.
Depending
on the setting of
the front panel
FOOT PEDAL SELECTOR
buttons,
the voltage
from
the
Foot
Controller
is
applied to
either the
VGA
(in
EXP
mode)
or to the
VCA
and
the
VCF
(in
EXP/WAH
mode).
The
Foot Switch
has
a
standard
(tip/sleeve)
phone
plug,
whereas
the
Foot
Controller, because
it
contains
more
circuitry, requires
a
stereo
(tip/ring/sleeve)
phone
plug.
Tremolo/Chorus
The
tremolo/chorus
effect varies the
volume
of the
output
signal,
and
also introduces
a
phase
shift.
Together, these
effects
simulate
a
rotating
speaker
when
used with
a
stereo sound system.
The volume
change
is
produced by
feeding
a
sub
oscillator
output
to
a
pair of
VCA's.
Selecting the
CHORUS
effect
sets
a
sub
oscillator to
its
very
slow speed
range (about
1/2 to
5Hz), whereas
TREMOLO
sets
the same sub
oscillator to
a faster
speed range (about 5
to
20Hz);
the exact speed
is
set
with
the
SPEED
control.
The
phase
shift
is
produced by
using an analog delay
line,
changing
the delay
in a
regular fashion with
a
clocking
circuit,
and mixing
delayed
and non-delayed audio
together.
The amount
of tremolo
or
chorus
effect
is
set with the
DEPTH
control.