7
VA 475
),
n
n-
- Scrap the contact surfaces of the earth point until
they are bright and grease with graphite grease.
Integrated fuses (Fuse)
The fuses integrated in the amplifier (Fuse) protect the
power amplifier and the entire electrical system in case
of an error. If a replacement fuse is used, never bridge
fuses or replace them with a type with higher current.
Connection examples
Connection of the voltage supply..................fig. 2
Connection to car sound system
with cinch output ..........................................fig. 3
Loudspeaker connections ............................fig. 4/5
Direct Aux Input.............................................fig. 6, 6a
High-Input......................................................fig. 7
+12V
Remote connection of the amplifier with switchable +12 V
voltage source.
This allows the amplifier to be switched on and off using
the on/off-switch of the radio device.
High-level inputs
The amplifier is equipped with high-level inputs to permit
connection to radios without preamp outputs (Fig. 7).
This enables direct connection to be made to the radio’s
loudspeaker output.
Direct Aux Input Connection
Connection options if the car radio has no AUX
input or if the AUX input is already connected
You can directly connect various AF sources (such
as an MP3 player or mobile navigation system) via
a 3.5 mm (0,35") jack plug optionally to the Direct
Aux Input. All signal sources will then be heard si-
multaneously and their volume must be adjusted
on the respective source device.
Note:
All AF sources must be set to Off during installa-
tion and connection!
Installing the jack-plug cable
Please use our 5 m (16.4 ft.) jack-plug cable (Or-
der No. 7 607 001 525) to make the connection.
A special feature is that it has its own On/Off
switch.
Switch position is OFF (•):
During installation and de-installation and when
no AF source is connected.
Switch position is ON (I / II):
Only after an AF source has been connected.
Caution:
When making the connection, always set the vol-
ume control to minimum and switch off the ampli-
fier.
Level control
The Level control is used to adjust the input sensitivity
of the power amplifier to the output voltage of your car
sound system preamplifier output.
The adjustment range is from 0.3 V to 8 V.
If a car sound system of a third party manufacturer is
connected, the input sensitivity must be adjusted cor-
responding to the manufacturer data.
A few important explanations in this context:
By turning the control clockwise, the input sensitivity of
the amplifier and, therefore, also the volume increases.
However, this is not a volume control; no further ampli-
fier output can be achieved in the end position, even if it
may sound like that at the beginning. The system merely
increases the volume faster if the volume control of the
car sound system is turned up.
Loudspeaker connections
(If the amplifier is to be jumpered, continue with the sec-
tion "Bridged loudspeaker connections" at this point).
As with every audio component, the correct polarisa-
tion of amplifier and loudspeakers is of essentially
importance for a good bass response. For this reason,
ensure that the positive (+) connection of the amplifier
is connected with the positive connection (+) of the
loudspeaker; the same applies to the negative (-) con-
nections. In addition, the left amplifier channel must
be connected with the left loudspeaker and the right
amplifier channel with the right loudspeaker.
Bridged loudspeaker connections
The GTA amplifier can also be bridged for a mono
configuration. This allows the amplifier to be used for
one or several subwoofers or mid-range drivers. In this
configuration, the amplifier combines the right and left
channel to a single-channel output (mono output).
Note:
The amplifier can add the right and left signal informa-
tion only if the right as well as the left RCA connection
were carried out.
Caution:
In a bridge circuit, the amplifier load must be 4 ohm
or higher. A lower load leads to an overheating or
switch-off of the amplifier and can cause permanent
damages.
Adjusting the type and range of the frequency
crossovers
With the VA 475, the type of frequency crossover (i.e.
"Low Pass" or "Hi-Pass") and the desired entry frequency
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