Audio; Output; Preferred Wiring - Orban 424A Operating Manual

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Connecting the
424A
Compressor
to
other
equipment
is
quite
straightforward.
Relatively
uncomplicated
systems
(such as
home
playback
systems, "semi-pro"
recording
studios,
electronic music
studios,
dance
bars, etc.)
tend
to
come
together
without
serious grounding
problems even
if
the wiring
practices are
somewhat
casual, provided that high
RF
fields
are not
present.
Unusual
situations
can be
analyzed
if
you
are
familiar
with
the
standard
rules
governing grounding and
interfacing
between balanced and unbalanced systems.
The
instructions
below
will
apply
to
the majority of
cases.
A
comprehensive
discussion of interconnections
and grounding can be
found
in
Appendix
A.
Input:
The
electronically-balanced input of
each
channel
of
the
424A Compressor
is
compatible with most
professional
and
semi-professional sound
equipment,
balanced
or
unbalanced, whose source impedance
is
600
ohms
or
less.
If it is
greater
(as in
some
vacuum-tube
audiophile preamps), a
minor modification
may
be
made
to
the
input to
accomodate
the situation. Please refer to
Appendix
A
for
further
details.
Nominal
input
level
is
between
-10
and +4dBm. The absolute overload
point
is
+20dBm.
Output: The two
outputs
of
each channel
of
the
424A
are electronically-balanced
to
ground.
The
source impedance
of
each
leg
is
47
ohms
in
parallel with lOOOpF to
the
chassis
(for
RFI
suppression).
Each output
is
capable
of driving loads of
600
ohms
or higher.
If
an
unbalanced output
is
required
(to
drive
unbalanced
inputs
of
other
equipment),
it
should be taken between the
(+)
output and
circuit
ground
.
DO NOT
GROUND
THE
(-)
OUTPUT.
While no immediate
damage
will
result, this
will
short
the output
of the
(-)
amplifier
to
ground through
a
47
ohm
resistor, significantly
stressing the output amplifier
1C
and
possibly
shortening
its
life
due
to
thermal
cycling.
Preferred
Wiring:
We
recommend
wiring
with two-conductor
shielded cable (such
as
Belden
8451 or
equivalent) because
signal
current flows through the
two
conductors
only.
The
shield
does not carry
signal,
is
used only
for shielding,
and
is
ordinarily connected
to
ground
at
one end
only.
The
following table
and diagram
are applicable to a great majority of
installations.
If
you wish
to use single-conductor shielded cable, see the section
immediately
below.
Q