JBL 6260 User Manual

In
bridged
mono
operation
the two
amplifier
channels are
driven
with
the same
signal
r
but
with
Channel
B
reversed
in
polarity.
The
speaker
cable
is
then
connected
to
the
two
channels'
red
binding
posts
(the
black
posts
are not
used in
bridged
mono
mode) •
In
this
case,
a
positive-going
signal
applied
to
the
Channel
A
input
appears
as a
positive-going
signal
at
the
Channel
A red
binding
post
and
as
a
negative-going
signal
at
the
B red
binding
post.
See
Figure
2-6.
NOTE;
The two
channels*
binding
posts
are
clustered
to fac-
ilitate
mono
connection
across
the
red
posts
with
a
standard
dual
banana
plug.
DO NOT
CONNECT
THE
TWO
RED
BINDING POSTS
TO
EACH
OTHER, and
DO NOT
GROUND
EITHER
SIDE
OF
THE
OUTPUT
IN
BRIDGED
MONO
MODE.
2.6
INPUT
IMPEDANCE
AND
TERMINATION
Audio
engineering
has
its
roots
in
the
telephone
industry,
and
"600
ohm
circuits"
(together
with
their
predecessors,
"500
ohm circuits")
are
carry-overs
from
telephone
transmission
practices.
Long
audio
transmission
lines,
like
their
video
counterparts,
must
be
properly
sourced
from
and
terminated
in
equipment
which
matches
their
characteristic
impedance
if
optimum
frequency
response
and
noise
rejection
are to
be
achieved.
However,
transmission
line
theory
and
techniques
are
not
only
unnecessary
but
impractical
within
modern
recording
studios,
broadcast
studios
and other
local
audio
systems
where
transmiss-
ion
circuits
are
seldom
more
than
several
hundred
feet
in
length.
The
advent
of
negative
feedback
circuitry
and
solid-state
elect-
ronics
has
spawned
modern
audio
amplifiers
and
other
signal
pro-
cessing
devices
having
source
impedances
of
only a
few
ohms.
They are
essentially
indifferent
to
load
impedances
and,
by
varying
their
output
current
inversely
to
changes
in
load
impedance,
maintain
the
same
output
voltage
into
any
load
impedance
above a
rated
minimum,
with no
change
in
frequency
response.
Modern
audio
systems,
therefore,
utilize
amplifiers
and
other active
devices
which
have
very
low
output
impedances
and
high
(lOK
to
50K ohm)
input
impedances.
These
products
may
thus
be
cascaded
(operated
in
series),
or
many
inputs
may be
connected
to a
single
output
of a
preceding
device,
without
regard
to
impedance
matching.
Switching and
patching
is
simplified
because
double
loads and
unterminated
bugaboos
are
essentially
elimin-
ated.
Floating
(ungrounded)
transformer
outputs
minimize
ground
loop
problems,
and
differential
transformerless
input
circuitry
(or
input
transformers)
minimize
common
mode noise or
interfer-
ence
which may
be
induced
into the
interconnecting
wires
or
cables.
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9
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JBL 6260 Specifications

General

Brand	JBL
Model	6260
Category	Amplifier
Language	English