Roland SH-1 - Page 22

MODULATOR
(LFO)
MODULATOR
The
Moduiator includes
an LFO and
an
S/H
as shown
beiow.
The
LFO is
an oscillator
which
generates
waveforms
of
a
low frequency. The
range is
from about
0.2
Hz
to about
25
Hz.
The
output
of the
LFO can be
used for
modu-
lating the VCO,
or VCF, and for
triggering
the
envelope
generators.
The S/H
{Sample and
Hold)
produces
random
signals
by
samplingthe output
from
the
noise
generator at a rate
determined
by
the
LFO (See
opposite
page),
1.
MODE SWITCH
This switch
determines
which
waveform
will be
used for
VCO and
VCF
modulation.
The^Xj
is
the most
commonly
used wave-
form.
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.
The other
positions are
more
often used
for
special effects.
For
example, using
the
square wave to
modulate
the VCO
pitch
wii!
produce
trills.
2.
RATE
CONTROL
The
RATE slider
controls the
frequency
of
the
modulator
output.
Raising the
control
increases
the frequency.
The
frequency can
be
visually checked by
means of the
LED.
For
vibrato-like effects,
this
controi
is
normally set at
about
"5".
©
©
CONSTRUCTION
AND
FUNCTION
OF
MODULATOR
LFO
GATE
J-LTLTL
MODULATOR
]
I
RANDOM
f
IKJ-
LFO
O—O-
o
ENV-1
o^
/^
VCO 4V
VCF
ENV-2
VCA
k
VCO
MOD
*
VCF
MOD
21