Pág. 6
AUDIMAX 362
SOLIDYNE
2.7
ADITIONAL TECHNICAL
INFORMATION:
Balanced and
unbalanced I/O
In the following paragraphs you will find
information about how to connect unbalanced
outs to balanced inputs, and vice versa. This
information will be of extreme utility, not only for
Audimax 362, but also for other equipment of your
radio. Different cases are decrypted.
2.7.1 Balancead lines
Balanced lines use three cables to transmit the
signal: positive, negative and ground. The
negative takes the same audio signal of that the
positive but inverted 180°. GND corresponds to
the shield of the cable, which rejects the
electrostatic noise (switches, big motors, etc.).
The fact that the audio signal is sent by two
cables, inverted in one of them, practically annuls
the noise induced on the cable, specially the
electromagnetic one, caused by fluorescent tubes,
AC lines, etc.
A balanced input amplifies only the
difference
between both positive and negative signal. Since
the induced noise causes the same deviation in
both cables, when reducing both signals the noise
is eliminated (the (-) wire invert its phase, then,
the induced noise is reduced to itself). In addition,
equipments that uses balanced I/O are of
professional category and uses line levels of
+4dBu (1,23 Volts). Connectors are XLR or stereo
plugs (one by channel).
2.7.2 Unbalanced lines
They are used in “home” and non-professional
equipment. The audio is sent by a pair of cables;
being the one alive and other the shield of the
cable. These cables are much more
sensible to
the noise
, mainly of electromagnetic type. They
handle line levels of the order of -10dBv (0.36
Volts).
The connectors typically used on this kind of units
are RCA o male plugs (TRS).
2.7.3 Unbalanced output to balanced input
In order to connect an unbalanced output to a
balanced input, you need to
unbalance the
input
. This is obtained sending to GND the
negative (-) terminal on the balanced input
connector, and connecting the other one to the
signal cable of unbalanced source. The ground of
the input must be connected to the output’s
ground (shield of the cable).
•
If the
input
is a
stereo jack
, the adaptation can
be made using a mono plug connected in the
following way: the shield to the sleeve and the
live to the tip. The sleeve of the mono plug will
send the negative terminal of balanced input
(jack’s ring) to GND.
•
If the input is of
XLR
type, the shield of the
unbalanced cable must be connected to pins 1
and 3 and the live to pin 2.
2.7.4 Balanced output to unbalanced input
For this case, leave unconnected the negative (-)
wire of the balanced output, joining the positive to
the unbalanced input.
•
If the balanced output have a stereo jack
connector and you need to connect it to an input
with mono jack (unbalanced), you can use a
stereo plug-plug cable, but disconnecting the ring
on the input plug. The connection is made using
the tip (signal) and sleeve (GND).
•
If the output is XLR type, leave unconnected the
pin 3, and connect the live to pin 2 and the shield
to pin 1. The other ends of the cable will have
RCA or mono plug connector.
•
If the unbalanced input is stereo, and uses an
stereo jack, you need to make an special cable,
in which the plug’s tip is connected to left channel
and the ring to the right channel, in both cases
unbalanced as was explained.
Summary of Contents for AUDIMAX 362
Page 2: ...P g 2 AUDIMAX 362 SOLIDYNE...
Page 4: ...P g 4 AUDIMAX 362 SOLIDYNE...
Page 18: ...SOLIDYNE AUDIMAX 362 P g 18...
