Description And Function Of - Orban 424A Operating Manual

The
de-esser
OPerate/DEFEAT
SWITCH
defeats the de-essing
action.
Because
it
defeats the control
loop only,
it
causes
no
clicks,
pops, or gain
changes
when
operated, and can be
freely
operated
in
the middle
of
program
material.
For example,
if
there are a
few problem
"esses"
in
mixed material, the de-
esser
can be
switched-in
momentarily
as
needed, eliminating the danger
of
unwanted
effects
on other program
material.
The NORMal
and
HEAVY
de-esser gain reduction
lamps
indicate, respectively,
when
normal and
potentially
excessive de-essing action
is
occurring.
—
The
COUPLED/ INDEPENDENT
switch
(424A
only)
permits the use
of the
two-
channel
unit
either
as
two
independent compressor/limiter/de-essers, or
as a
coupled stereo
unit.
In
the
COUPLED
mode,
the gain reduction
in
both
channels tracks that channel
calling for
the most gain reduction at any given
instant.
Therefore,
stereo
imaging
is
always preserved even
if
operating
controls
are adjusted differently
on the
two
channels. (Ordinarily,
they would
be
adjusted to
be
as identical as possible.)
Even
in
COUPLED
mode,
the de-essers
remain
independent. This
is
because
it
has been found that
their short release
times
result in
no stereo imaging
problems
despite their
independent operation.
The
POWER
ON/OFF
switch
is
self-explanatory.
Using
The Compressor/Limiter
To
use the
Compressor/Limiter
section of the
424A,
switch the compressor/limiter
OPerate/DEFEAT
switch
to
OP.
Adjust
the
ATTACK
TIME,
RELEASE
TIME,
RELEASE
SHAPE,
and
RATIO
controls
to achieve the sound
desired.
(An explanation
of
the operating controls
is
found
above
in
Description
and
Function of Front-Panel Features.)
Adjust
the
INPUT ATTENuator
control until
the desired
amount
of gain
reduction
is
indicated on the
G/R METER.
Be
careful not
to
over-compress such that the
G/R METER
enters
the red section
of the scale.
You
may
wish to readjust the
ATTACK,
RELEASE,
and
RATIO
controls to "fine-tune" the
sound to
your
taste.
This
will
often
result
in
a
change
in
the
amount
of
gain reduction,
and you
may
wish
to readjust the
INPUT ATTENuator
to
compensate.
If
you hear a "hashy"
distortion
on voice, or on instruments
like
electric bass,
synthesizer,
or
Hammond
organ,
this
can be completely eliminated by slowing
down
the attack time. (The "hash"
is
caused by the very
fast
release-time peak
limiting
function modulating the instrument
waveforms. By
slowing the attack time, you
produce
less
peak
limiting,
forcing the
424A
to
behave more
like
a
pure
compressor.)
If
you
hear unnatural "pumping" or "breathing",
this
can be eliminated by slowing
the
release time and/or by using the gating functions.
in
general, the peak
level at
the
424A
output
is
relatively
constant regardless
of
the
adjustment of the
ATTACK
and
RELEASE TIME
controls.
If
you choose
a
relatively
low
RATIO,
the peak
level will
decrease
at
gain reductions
less
than
25dB. This prevents
VCA
clipping
if
the
input level
rises
sufficiently
to cause a
full
25dB
of
gain reduction,
since the
output
level will,
in
this
case,
increase
significantly
due
to
the low compression
ratio.
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