OPERATING INSTRUCTIONS
4 channel mini amplifier
°
Item-No. 37 28 07
Intended use
The 4 channel mini amplifier is to be used for the amplification of low level audio signals in vehicles.
This product may only be operated when it is connected to a 12V DC car power supply, with the negative terminal of the car battery
connected to the body. It may only be installed and operated in vehicles equipped with this type of voltage supply.
By the way of installation, the user has to ensure that the 4 channel mini amplifier is protected against moisture and dampness.
Any use, other than that described above, may lead to damage to this product and involves other risks, such as short circuit, fire,
electric shock.
The 4 channel mini amplifier must not be changed or modified in any way. Do not open the housing!
Always observe the safety instructions.
Safety Instructions
The warranty will be void in the event of damage caused by failure to observe these safety instructions!
We do not assume liability for any resulting damage.
Nor do we assume liability for damage to property or personal injury caused by improper use or failure to
observe the safety instructions. The warranty will be null and void in such cases.
This symbol indicates important information in the instructions. Prior to starting up the product read the
entire operating instructions, they contain important information on the correct operation.
• For safety and licensing reasons, unauthorised conversion and/or modifications to the product are not permitted.
• The device may only be used with a 12 V DC vehicle power supply (with the negative terminal of the battery connected to the
body of the vehicle). Never connect the 4 channel mini amplifier to any other voltage supply.
• Never pour liquids on to electrical devices, and never place any objects containing liquids (such as vases) on top of them or
near them. There is a high risk of fire.
• Do not expose the 4 channel mini amplifier to high temperatures, dripping or spray water, strong vibration or high mechanical
loads.
• If you have doubts about how the equipment should be operated or how to safely connect it, consult a trained technician.
• Do not leave packing materials unattended. It may become a dangerous plaything for children.
• Do not operate the device when it is unattended.
• Also observe the safety and operating instructions of any other devices which are connected to your device.
• Please, also observe the additional safety instructions in each individual section of these instructions.
• When in doubt about how to connect the device correctly, or should any questions arise that are not answered in these
operating instructions, contact our Technical Advisory Service or another expert.
Mechanical Installation
Modifications to the vehicle which are made necessary through the installation of the 4 channel mini
amplifier or other components must always be carried out in such a manner that neither the traffic safety
nor the designed stability of the car is impaired. With many vehicles, the MOT will be void, if you cut out
a section of the sheet metal.
If you are in doubt, when selecting a place for installation, consult your car dealer.
Since the 4 channel mini amplifier generates heat the place of installation must be resistant against heat.
To ensure adequate ventilation, there must be an open space of 5 cm round the housing of 5 cm. Apart
from this, the air circulation may not be obstructed by objects such as magazines, blankets, covers or
such like.
Make sure before drilling the attachment holes that no electric cables, brake lines, the fuel tank or similar
will be damaged.
When using tools to install your car’s hi-fi components, follow the manufacturer’s safety instructions.
When installing the car’s hi-fi system, take into consideration the risks that can arise from devices being
torn away in the case of an accident. Therefore, you should secure each component in a place where it
cannot pose a risk to passengers.
• Mark the holes for the screws, where it is to be installed. For this, use the device itself as a template.
• Drill the holes for the fastening screws.
• Fasten the 4 channel mini amplifier with screws, which are suitable for the mounting surface.
Connecting the Power Supply
The electric connection should always be carried out by a specialist.
To avoid short circuits and any resulting damage to the device, the negative terminal (earth) of the car
battery must first be disconnected.
Before reconnecting the negative terminal to the battery, ensure that the 4 channel mini amplifier has been
completely connected and that the connection has been checked.
Only use a volt meter, or a diode test lamp, to check the voltage of the vehicle system leads, as normal test
lamps consume excessive voltage and may thus damage the vehicle’s electronics.
When installing the cables, ensure that these are not squashed or scraped on sharp edges! Use cable
inserts for penetrations.
In order to reduce parasitic induction of the generator or of other electric systems of the vehicle, the
4 channel mini amplifier should be directly powered by the car battery. It is not allowed to supply other
electric loads, such as the cooling fan, the windscreen washer etc., via the same cable as the 4 channel
mini amplifier.
Use connecting cables with an as large a cross-section as possible for connecting to the power supply
and the amplifier earth. The necessary cable cross-section depends on the power requirements of the
components connected.
If the cable cross-section is too small, it can cause the cable to char in unfavourable cases. Moreover, the
increased ohmic resistance leads to unnecessary losses of power.
An additional fuse in the positive connection of the 4 channel mini amplifier is necessary in any case (fuse holder
is not included in the scope of delivery). The fuse should be installed close to the battery. In the event of a shortcircuit (e.g. the connecting cable fraying), the fuse disconnects the positive circuit. Thus, damage to the battery
or a cable fire in the supply cable is prevented.
The strength of the fuse depends on the power consumption of the devices connected to the car hi-fi
system.
• Connect the plug of the connection cables to the connector OUTPUT/POWER at the 4 channel mini amplifier.
• (1) Connect the red cable of the power supply directly to the positive terminal of the car battery.
• (2) Connect the black cable of the power supply to the negative terminal (ground) of the battery or to the car body.
• (3) Connect the orange cable of the power supply, to the remote control connection of the car radio’s aerial control output.
Connecting the Loudspeaker Outputs
The loudspeakers must be connected with two-core cables. Insulate the bare wires at the connecting terminals.
Ensure there are no sharp edges, which could damage the cables.
Only use loudspeakers that have a sufficiently high power rating (see „Technical Data“).
Ensure that all the loudspeakers have the correct polarity, i.e. the plus and minus signs must match.
The 4 channel mini amplifier has been built for a loudspeaker impedance of at least 2 ohms. Never connect
loudspeakers with a lower impedance.
• Connect the loudspeakers to the cable endings of the connection cable which is already connected to the connector
OUTPUT/POWER of the 4 channel mini amplifier.
• The cable configuration is printed on the housing of the device:
1L+ > positive loudspeaker connector at left front
1L- > negative loudspeaker connector at left front
1R+ > positive loudspeaker connector at right front
1R- > negative loudspeaker connector at right front
2L+ > positive loudspeaker connector at left rear
2L- > negative loudspeaker connector at left rear
2R+ > positive loudspeaker connector at right rear
2R- > negative loudspeaker connector at right rear
Connecting the Inputs
To connect the cinch inputs, only use suitable, shielded cinch wires. The use of other cables might cause
interference.
Keep the length of the cables as short as possible.
Do not place the cables near other cables. In this way, you can avoid stray pick-up on the amplifier input.
To avoid distortion or mismatching that may damage the 4 channel mini amplifier, only sources with a cinch
output may be connected to the cinch inputs of the device.
• Connect the cinch outputs of your car radio to the cinch connections INPUT of the 4 channel mini amplifier.
• Here, connect the front cinch output of the car radio with the input INPUT 1 and the rear cinch output with the input INPUT 2.
• Observe the right-left marking of the cinch connections: L = left, R = right
Use and Initial operation
• If you have checked the cable connections, reconnect the negative terminal of the battery.
• Turn the controls LEVEL 1 and 2 counter-clockwise to minimum.
• Slide the switch FILTER 1 and 2 into the position corresponding to your configuration.
• The switch FILTER 1 affects the diplexer for the front loudspeakers. The switch FILTER 2 affects the diplexer for the rear
loudspeakers.
OFF: Diplexer switched off, device plays back the complete frequency range
L: Low-pass filter switched on, device only plays back the bass range
H: High-pass filter switched on, device only plays back the treble range
• Switch on your car radio and set the volume to ca. 75% of the maximum volume.
• Now, use the LEVEL 1 and 2 controls to adjust the maximum volume of the loudspeakers to a value which is acceptable for
you.
• The control LEVEL 1 affects the volume of the front loudspeakers. The control LEVEL 2 affects the volume of the rear loudspeakers.
• Then, set a medium volume level with the volume control of the car radio. From now, the total volume is only to be adjusted
by the volume control unit of the car radio.
Disposal
Dispose of the product in accordance with the legal regulations that apply.
Technical Data
Operating voltage 12Vdc
Fuse F10AL/250V (6x32mm)
Power output (4 ohms) 4 x 11.5W RMS
4 x 50W max.
Frequency range 20-20,000Hz
Distortion factor <0,1%
Channel separation >55 dB
S/N ratio >90dB
Dimensions 110 x 80 x 40mm
Weight 250g
Version 03/10
These operating instructions are a publication by Conrad Electronic SE, Klaus-Conrad-Str. 1, D-92240 Hirschau (www.conrad.com).
All rights including translation reserved. Reproduction by any method, e.g. photocopy, microfilming, or the capture in electronic data pro-
cessing systems require the prior written approval by the editor. Reprinting, also in part, is prohibited.
These operating instructions represent the technical status at the time of printing. Changes in technology and equipment reserved.
© Copyright 2010 by Conrad Electronic SE.