Roland JV-80 Owner's Manual page 105

1.
Patch
Edit
TVF
Parameters Selected
by
TVF
(3
Pages)
The functions of the
TVF
are set
in
these pages.
ic Filter
Type and
Cutoff
Frequency
Generally, the
TVF
is
used
to filter
out,
or "cut
off," the
high frequency elements of a
waveform, making what
is
called a
low
pass
filter
(LPF).
The
timbre of
the
sound
becomes
brighter
when
setting
the cutoff
frequency
to
high
values, since
high frequency elements
are
allowed
to
pass through.
The
opposite effect
can be achieved by
setting the
cutoff
frequency
to a
low
value,
filtering
out the high frequency elements
and making
the timbre
of
the
sound more
mellow
and closer
to
the pure
quality
of
a sine
wave.
Increasing the level of the
envelope
turns the
TVF
type
to a
high pass
filter
(HPF),
causing the
timbre of
the
sound
to change, but
leaves the bright portion or sharp portion of
the
sound unchanged. For
both
types, the filter
is
applied around
the
cutoff frequency.
ic Cutoff
and
Envelope
The
"normal"
cutoff frequency,
set in
the cutoff parameter,
is
that
frequency
where
the level
of the
envelope
is
0.
Therefore, the cutoff frequency increases or decreases according
to
changes
in
the envelope
level.
•lAr
Resonance
This creates a characteristic
sound by emphasizing
the
frequency elements around
the cutoff frequency of the
TVF.
It
is
effective
in
making
sound programs which have
a characteristic electronic
or synthesizer-type sound, such
as
synth bass and synth
lead.
The
emphasized frequency changes along with
the cutoff frequency,
when
the
cutoff frequency
is
modulated by
the
envelope.
•k
Resonance
Mode
When
the
way
that
resonace
is
applied
is
set to
SOFT,
the
sound
has a
subtle,
moderately electronic
feel.
When
set to
HARD,
the
resonance
is
applied sharply
and
the
timbre of
the
sound
is
drastically
changed.
It is
recommended
to set
it
to
HARD
when you want
to
reproduce
dynamic
resonance
effects characteristic
of analog synthesizers,
like the
resonance
that results just
before
oscillation.
iK Cutoff
Key
Follow
These parameters
let
you change the cutoff frequency depending of
the
key position and
velocity.
Set
the
key follow
value
to less
than 100
for
piano
sound
programs, since the sound of an
actual
piano
becomes
softer the higher
up on
the
keyboard
you
play.
If
you
set different
key follow values
for
each Tone, the
way
that
the
sound program changes
becomes
irregular.
>: Envelope
This makes changes
in
the cutoff frequency
over
time,
within
the
range
set
by
the depth parameter.
If
you
find
that
the
sound doesn't change
as
much
as
you want
it
to,
even
when
the
envelope
is
set to
a high value,
you can
increase
the depth.
The
brightness and sharpness
(high
overtones or harmonics) of
the
sound of stringed instruments
(e.g.,
harp and
guitar)
and of
percussion
(e.g., bells
and vibraphone)
gradually fade
as
the
sound
decays.
To
effectively reproduce
these kinds of instruments,
we
suggest
that
you
set the
TVF
envelope
to
its
highest point
at
the beginning of
the
sound, then
have
it
decrease gradually.
On
the other hand,
you
can obtain the
opposite kind of
effect for instruments
like a
gong,
which
increases
in
brightness
as
the
sound
sustains; to
do
this,
have
the
TVF
envelope gradually
increase
in
level
from key
on.
105