8182A Audio Processor Controls - Orban 8182A Operating Manual

8182A
Audio
Processor Controls
(Corresponding
controls
on
the
8182A/ST
Studio Chassis have
the
same
functions.)
HF
LIMIT
indicators
light
when
the
high-frequency content
of
audio
is
being
limited.
GATE
Indicator
lights
when
the input
audio
level
falls
below
the threshold set
by
the
gate
threshold
control.
When
this
happens,
the
compressor's recovery time
is
drastically
slowed
to
prevent noise rush-up during
low-level
passages.
POWER
indicator
lights
when
the unit
is
powered.
VU
meter and
selector
switch
display signal
level at
various points
in
the
circuitry
(see Block
Diagram
in
8182A
Operating
Manual)
to aid
in
diagnosing
faults.
The
meter also displays
+15V
and
-15V power
supply voltages
(with
100%
corresponding
to
15VDC).
LOUDNESS CONTROL
switch
determines
whether
the
circuitry
that controls
sub-
jective loudness (as
opposed
to
objective
level) is
activated.
This
circuitry
will
control
the
loudness
of
most commercials
sufficiently
well to eliminate
viewer
annoyance.
INPUT
ATTENUATOR
controls
adjust the signal
level
going
into
OPTIMOD-TV.
RELEASE SHAPE
switch
switch selects either
a constant release
rate
(when
set
to LiNear) or
(when
set
to
Exponential)
a
rate that automatically
becomes
faster
as the
release
process
progresses.
COMPRESSOR
switch
(used
for testing)
disables the dual-band
compressor
when
set
to
PROOF.
LIMITER
switch
(used
for testing)
disables the high-frequency
limiter,
Hilbert
Trans-
form
Clipper,
and
FCS
Overshoot
Compensator
when
set
to
proof.
CLIPPING
control
adjusts signal level
going
into the Hilbert
Transform
clippers,
and
therefore
determines
the
amount
of
peak
limiting
done
by
clipping.
This
control
governs
the trade-off
between
loudness
and
distortion.
Settings
at
or
below -1
will
produce no
audible distortion
unless the
release time
control
is
set
much
faster
than
recommended.
H-F LIMITING
control determines
the
amount
of
high-frequency
limiting.
When
set
toward soft, the highs are
controlled
more
by
limiting,
which tends
to
soften highs but
does
not
produce
distortion.
When
set
toward hard,
the highs are controlled
more
by
clipping,
which
results
in
brighter
sound
(but
could
potentially distort highs).
RELEASE
TIME
control determines
how
fast
the gain of the
master compressor
increases
when
the
program
material gets
quieter.
BASS
COUPLING
control determines
the
degree
to
which
the
bass band
of
the
compressor
tracks the
master band. Settings
toward
wideband produce an
air
sound
that
is
more
faithful to
the spectral
balance
of
the
source
material.
Settings
toward
in-
dependent
produce bass balances
that
are
more
uniform
between program segments
(often with increased bass).
GATE THRESHOLD
control determines the lowest
input level that
the
system
considers program. Levels below
this
are
considered
noise,
and
they
will
cause
the
AGC/compressor
to
gate,
effectively
freezing
its
gain
to
prevent noise "breathing"
during
pauses
or low-level
passages.
OUTPUT ATTENUATOR
controls match
the
output
level to
the stereo generator.
5-2