Roland SH-1 Instruction Manual page 23

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
at
the
right.
The 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".
GATE TRIGGER SWITCH
When
the
GATE
TRIG
switch
of the
envelope
generator
is
set
at
the
LFO
position, 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 begin-
ning,
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 the
LFO
waveforms
when
a gate pulse occurs.
SAMPLE/HOLD
The S/H
(Sample
and Hold)
produces
random
voltage
sequences by
sampling
input
waveforms. Each sample represents
the
voltage
level at
the instant the
sample
was taken.
The
HOLD
portion of the
circuit
holds this
voltage level until
the
next sample
is
taken.
The
result
of
this
is
a
control
voltage
output
which changes
stepwise
in
random
patterns.
When
used to
control the
VCO,
this
produces notes
with
random pitch patterns
when
the
Envelope
Generator
GATE TRIG
switch
is
set at
LFO
and
a
key on
the
keyboard
is
pressed,
as
shown below.
EXAMPLE OF
DELAYED VIBRATO
Cmaj7
Am7
££
aj,i.
IlJ
Dm?
0^
Dm7(onG)
I
&*-
*
KEY TRIGGER
ACTING ON PHASE OF EACH
WAVE
SINE
WAVE
to,)
SQUARE WAVE
cru)
KYBD
GATE
FUNCTION OF SAMPLE &
HOLD
NOISE
WAVEFORM
SAMPLING
PULSE
LLL
1111
S/H
OUTPUT
VOLTAGE
r>
£
s
M-fr
h
h
5
m
EXAMPLE
OF SETTING FOR
RAMDOM NOTE
B
Roland
SVfTTHESlEER
IOSL
SH-1
MODULATOR
uax
as
&?*
EHV-2
i
«
y "1 ^
-
—
Dl =
=
L'
D
m-
•
w w
VCA
>
*
xo
.
""""
—
m
•E i
1
A
•
-i
h*
,
j
22