Table of Contents
Advertisement
LFO
- LOW
FREQUENCY
OSCILLATOR
The
LFO
is
an
oscillator
which
generates
wave-
forms
of a
low
frequency.
The
range
is
from
about 0.2Hz
to
about 25Hz.
The
output
of the
LFO
can
be
used
for
modulating
the
VCO,
VCF,
or
VCA,
and
for triggering the
envelope
generators.
1.
WAVEFORM
SWITCH
This switch determines
which waveform
will
be
used
for
VCO, VCF,
and/or
VCA
modulation.
The
r
\
j
is
the
most
commonly
used
waveform.
Controlling the
VCO,
it
produces
vibrato
effects,
or pitches
which sweep up and down.
Controlling
the
VCF,
it
produces growl
effects
(with
faster
LFO
rates)
or
tone color
vibrato,
which
occurs
in
some
instruments
in
conjunction
with
pitch
vibrato.
Controlling the
VCA,
it
produces tremolo
effects,
which
is
a slight
varying
of the loudness.
The
other
waveforms
are
more
often
used
for
special
effects.
For example,
using the square
wave
to
modulate
the
VCO
pitch
will
produce
trills.
2.
RATE
CONTROL
The
RATE
slider
controls the
frequency
of the
waveforms.
Raising
the
control
increases
the
frequency.
The
frequency can be
visually
checked
by
means
of the
LED.
For
vibrato-like effects,
this
control
is
normally
set at
about "5"
3.
DELAY
TIME
CONTROL
When
this
control
is
raised,
pressing
a
key
on
the
keyboard
will
produce
a
delayed
entry of the
sine
.
wave.
This
is
especially
effective
for
delayed
vibrato
effects,
such
as in
the musical
example
shown
below.
Delayed
sine
wave
is
also useful
for
delayed growl
or
wah
wah, and
for
delayed
tremolo.
If
delayed entry
of the
sine
wave
is
not
desired,
then
this
control
must
be
set at
"0".
(The
other
LFO
waveforms
are
not
affected
by
this
delay
effect).
4.
KYBD
TRIG
(KEYBOARD
TRIGGER)
SWITCH
The
normal
position
of
this
switch
is
OFF.
When
it
is
ON,
the
frequency
of the
LFO
is
locked to
the
keyboard
gate
pulse.
What
this
means
is
that
when
a
keyboard
gate pulse appears,
it
triggers
the
LFO
to begin
its
wave
generating
process
from
the beginning, or
in
other
words
from
the highest
level
contained
in
the
waveform.
With
some
uses of the
LFO,
this
is
a
desirable
feature.
The
drawing
at
the
right
shows what
happens
to
each
of
the
LFO
waveforms
when
a
gate pulse occurs.
When
triggering
the
envelope
generator with the
S/H
clock
(KYBD
MODE
switch
in
EXT
CV/
GATE/IS/H)
position), leave
the
KYBD
TRIG
switch
OFF.
i'LPfr
FUNCTION OF KEY TRIGGER
EXAMPLE OF DELAYED VIBRATO
Experiment
it
with
7.
VIOLIN
of
SAMPLE
SOUND
PATCHES
- GROUP
3.
STRING INSTRUMENT.
17
Advertisement
Table of Contents
