<s>
The	O
RCA	B-Protocol
connector	I-Protocol
is	O
a	O
type	O
of	O
electrical	B-Protocol
connector	I-Protocol
commonly	O
used	O
to	O
carry	O
audio	O
and	O
video	O
signals	O
.	O
</s>
<s>
The	O
connectors	O
male	O
plug	O
and	O
female	O
jack	O
are	O
called	O
RCA	B-Protocol
plug	I-Protocol
and	O
RCA	B-Protocol
jack	I-Protocol
.	O
</s>
<s>
It	O
is	O
also	O
called	O
RCA	O
phono	B-Protocol
connector	I-Protocol
or	O
phono	B-Protocol
connector	I-Protocol
.	O
</s>
<s>
The	O
word	O
phono	O
in	O
phono	B-Protocol
connector	I-Protocol
is	O
an	O
abbreviation	O
of	O
the	O
word	O
phonograph	O
,	O
because	O
this	O
connector	O
was	O
originally	O
created	O
to	O
allow	O
the	O
connection	O
of	O
a	O
phonograph	O
turntable	O
to	O
a	O
radio	O
receiver	O
.	O
</s>
<s>
RCA	B-Protocol
jacks	I-Protocol
are	O
often	O
used	O
in	O
phono	O
inputs	O
,	O
a	O
set	O
of	O
input	O
jacks	O
usually	O
located	O
on	O
the	O
rear	O
panel	O
of	O
a	O
preamp	O
,	O
mixer	O
or	O
amplifier	O
,	O
especially	O
on	O
early	O
radio	O
sets	O
,	O
to	O
which	O
a	O
phonograph	O
or	O
turntable	O
is	O
attached	O
.	O
</s>
<s>
In	O
the	O
1950s	O
,	O
RCA	B-Protocol
connectors	I-Protocol
began	O
to	O
replace	O
the	O
older	O
quarter-inch	O
(	O
inch	O
)	O
phone	B-Device
connectors	I-Device
for	O
many	O
other	O
applications	O
in	O
the	O
consumer	O
audio	O
world	O
when	O
component	O
high-fidelity	O
systems	O
started	O
becoming	O
popular	O
during	O
the	O
transistor	O
revolution	O
.	O
</s>
<s>
Refinement	O
of	O
the	O
RCA	B-Protocol
connectors	I-Protocol
came	O
with	O
later	O
designs	O
,	O
although	O
they	O
remained	O
compatible	O
.	O
</s>
<s>
The	O
jack	O
has	O
a	O
small	O
area	O
between	O
the	O
outer	O
and	O
inner	O
rings	O
which	O
is	O
filled	O
with	O
an	O
insulator	O
,	O
typically	O
plastic	O
(	O
very	O
early	O
versions	O
,	O
or	O
those	O
made	O
for	O
use	O
as	O
RF	B-Protocol
connectors	I-Protocol
,	O
used	O
ceramic	O
)	O
.	O
</s>
<s>
The	O
RCA	B-Protocol
connector	I-Protocol
was	O
initially	O
used	O
for	O
audio	O
signals	O
.	O
</s>
<s>
As	O
with	O
many	O
other	O
connectors	O
,	O
it	O
has	O
been	O
adopted	O
for	O
uses	O
other	O
than	O
originally	O
intended	O
,	O
including	O
as	O
a	O
DC	O
power	O
connector	O
,	O
an	O
RF	B-Protocol
connector	I-Protocol
,	O
and	O
as	O
a	O
connector	O
for	O
loudspeaker	O
cables	O
.	O
</s>
<s>
RCA	B-Protocol
connectors	I-Protocol
and	O
cable	O
are	O
also	O
commonly	O
used	O
to	O
carry	O
S/PDIF	O
-formatted	O
digital	O
audio	O
,	O
with	O
plugs	B-Protocol
colored	O
orange	O
to	O
differentiate	O
them	O
from	O
other	O
typical	O
connections	O
.	O
</s>
<s>
One	O
or	O
more	O
sets	O
are	O
often	O
found	O
on	O
TV	O
sets	O
to	O
facilitate	O
connection	O
of	O
camcorders	O
,	O
other	O
portable	O
video	O
sources	O
and	O
video	B-Device
game	I-Device
consoles	I-Device
.	O
</s>
<s>
The	O
hot	O
signal	O
wire	O
and	O
signal	O
ground	O
provided	O
by	O
an	O
RCA	O
connection	O
implement	O
an	O
unbalanced	B-Protocol
connection	O
.	O
</s>
<s>
Using	O
RCA	B-Protocol
connectors	I-Protocol
,	O
each	O
signal	O
requires	O
its	O
own	O
plug	O
.	O
</s>
<s>
This	O
situation	O
is	O
made	O
worse	O
if	O
one	O
considers	O
more	O
complex	O
signals	O
like	O
component	O
video	O
(	O
a	O
total	O
of	O
three	O
for	O
video	O
and	O
two	O
for	O
analog	O
audio	O
or	O
one	O
for	O
digital	O
coaxial	B-Protocol
audio	I-Protocol
)	O
.	O
</s>
<s>
There	O
have	O
been	O
attempts	O
to	O
introduce	O
combined	O
audio/video	O
connectors	O
for	O
direct	O
signals	O
,	O
but	O
in	O
the	O
analog	O
realm	O
none	O
of	O
these	O
has	O
ever	O
become	O
common	O
,	O
with	O
the	O
exception	O
of	O
Europe	O
where	O
the	O
SCART	B-Protocol
connector	I-Protocol
was	O
very	O
successful	O
.	O
</s>
<s>
For	O
a	O
time	O
the	O
5-pin	O
DIN	B-Architecture
connector	I-Architecture
was	O
popular	O
for	O
bi-directional	O
stereo	O
connection	O
between	O
A/V	O
equipment	O
,	O
but	O
it	O
has	O
been	O
entirely	O
displaced	O
on	O
modern	O
consumer	O
devices	O
.	O
</s>
<s>
Though	O
RF	O
modulators	O
inherently	O
transmit	O
combined	O
A/V	O
signals	O
in	O
video	O
applications	O
,	O
they	O
depend	O
on	O
broadcast	O
television	O
systems	O
and	O
RF	B-Protocol
connectors	I-Protocol
which	O
are	O
not	O
universal	O
worldwide	O
;	O
RF	O
signals	O
are	O
also	O
generally	O
inferior	O
to	O
direct	O
signals	O
due	O
to	O
protocol	O
conversion	O
and	O
the	O
RF	O
limitations	O
of	O
the	O
three	O
major	O
analog	O
TV	O
systems	O
(	O
NTSC	O
,	O
PAL	B-Language
and	O
SECAM	O
)	O
.	O
</s>
<s>
Before	O
HD	O
television	O
became	O
a	O
standard	O
,	O
nearly	O
all	O
TV	O
sets	O
,	O
VCRs	O
,	O
and	O
DVD	O
players	O
sold	O
in	O
Europe	O
had	O
SCART	B-Protocol
connectors	I-Protocol
,	O
although	O
these	O
are	O
sometimes	O
supplemented	O
by	O
RCA	O
and/or	O
RF	B-Protocol
connectors	I-Protocol
.	O
</s>
<s>
SCART-RCA	O
adapters	B-Device
also	O
exist	O
,	O
which	O
usually	O
allow	O
input	O
of	O
composite	O
video	O
and	O
stereo	O
audio	O
.	O
</s>
<s>
Outside	O
Europe	O
,	O
separate	O
RCA	B-Protocol
connectors	I-Protocol
are	O
usually	O
used	O
,	O
supplemented	O
by	O
RF	B-Protocol
connectors	I-Protocol
for	O
backward	B-General_Concept
compatibility	I-General_Concept
and	O
simplicity	O
.	O
</s>
<s>
Although	O
mini-DIN	B-Protocol
connectors	I-Protocol
are	O
used	O
for	O
S-Video	O
connections	O
,	O
composite	O
video	O
,	O
component	O
video	O
,	O
and	O
analog	O
audio	O
(	O
mono	O
or	O
stereo	O
)	O
all	O
use	O
RCA	B-Protocol
connectors	I-Protocol
unless	O
the	O
signals	O
are	O
sent	O
via	O
SCART	B-Protocol
.	O
</s>
<s>
In	O
the	O
digital	O
realm	O
,	O
however	O
,	O
combined	O
A/V	O
connectors	O
are	O
gaining	O
ground	O
;	O
HDMI	B-Protocol
is	O
commonly	O
used	O
today	O
for	O
consumer	O
electronics	O
,	O
and	O
DisplayPort	B-Protocol
,	O
a	O
potential	O
competitor	O
to	O
HDMI	B-Protocol
,	O
is	O
often	O
found	O
on	O
home	O
computers	O
and	O
peripherals	O
.	O
</s>
<s>
Plugs	B-Protocol
and	O
sockets	O
on	O
consumer	O
equipment	O
are	O
conventionally	O
color-coded	O
to	O
aid	O
correct	O
connections	O
.	O
</s>
<s>
Stereo	O
audio	O
applications	O
use	O
either	O
black	O
and	O
red	O
,	O
grey	O
and	O
red	O
,	O
or	O
white	O
and	O
red	O
RCA	B-Protocol
connectors	I-Protocol
;	O
in	O
all	O
three	O
cases	O
,	O
red	O
denotes	O
right	O
.	O
</s>
<s>
Some	O
older	O
tape	O
recorders	O
,	O
and	O
equipment	O
like	O
receivers	O
designed	O
to	O
connect	O
to	O
them	O
,	O
use	O
a	O
5-pin	O
DIN	B-Architecture
connector	I-Architecture
to	O
connect	O
left	O
and	O
right	O
for	O
record	O
and	O
playback	O
with	O
a	O
single	O
cable	O
.	O
</s>
<s>
Adapters	B-Device
between	O
this	O
connector	O
and	O
RCA	B-Protocol
connectors	I-Protocol
have	O
used	O
white	O
and	O
red	O
for	O
left	O
and	O
right	O
channel	O
recording	O
,	O
and	O
blue	O
(	O
or	O
sometimes	O
black	O
)	O
and	O
yellow	O
for	O
playback	O
,	O
but	O
this	O
is	O
not	O
universal	O
.	O
</s>
<s>
Most	O
modern	O
equipment	O
with	O
RCA	B-Protocol
connectors	I-Protocol
for	O
recording	O
devices	O
simply	O
uses	O
white	O
and	O
red	O
for	O
all	O
stereo	O
pairs	O
,	O
whether	O
record	O
or	O
playback	O
.	O
</s>
