Roland SH-1 Instruction Manual page 10

VCO
-
VOLTAGE
CONTROLLED OSCILLATOR
VCO
(Voltage Controlled Oscillator)
The
VCO
is
the primary
sound source of
the synthesizer
and
generates the basic
waveforms.
The
frequency
or
pitch of
these
waveforms
is
controlied by
a
controi
voltage.
VCO CONTROL VOLTAGE
INPUTS
The most important control of
VCO
pitch
is
by
means
of
the
keyboard
control voltage
and
the
BENDER
controi voltage.
The
keyboard
control voltage
is
internally
connected to
the
VCO. The
BENDER
control voltage
is
connected through
the
BENDER
SENSITIVITY
control.
Other
sources of control
voltage for
control of the
VCO
are:
MOD
(Modulator)
and
AUTOBEND
voltage,
and
the
S/H.
Each
of these
may
be fed to
the
VCO
in
the
amounts needed
to
produce the desired
effects.
1.
MOD
(Modulator or
LFO)
With
the
MOD
slider at
high position,
the
VCO
is
modulated by
the output signals
of
Modulator.
The
VCO
pitch
will
vary as
shown
in
(1), (2),
and
(3)
at
the
right,
depending on
the setting of
the
Modulator
MODE
switch.
(1)
Pitch
varies
continuously
to give
vibrato
effects.
(2)
Pitch varies as in a
trill.
(3)
Pitch varies irregularly to give
random
notes.
2.
AUTOBEND
DEPTH
This controi adds
a
change
of pitch
at
the
beginning of
each note
played.
By
raising
this
control, the
VCO
pitch
is
controlled
by
a
voltage
envelope
as
shown
in (4)
so
that the
sound
starts
with a
lower
pitch.
The
human
voice,
whistling,
and other
sound
sources
which
begin
on tower pitches
will
sound
more
real
and
natural using
this.
3.
AUTOBEND
TIME
This controls the
time required for the
VCO
to return to
its
normal pitch
when
using the
AUTOBEND.
Raising the slider
increases the time.
Normally, this slider
is
set
between
and
5; special effects are
obtained with higher
settings.
(1)MOD(^)
8
PITCH
TIME
(2)MOD.(n_l)
h
—
PITCH
\>
TIME
(3)MOD.(Random)
h
PITCH
TIME
(4)AUTOBEND
-*
p
CHANGE
OF PITCH