Blaupunkt Stereo Amplifier MPA 400US User Manual

M P A M U L T I - C H A N N E L P O W E R A M P L I F I E R  
3/2 CHANNEL POWER AMPLIFIER  
M
P
A 400u  
s
CH3  
+
SPEAKERS  
CH2  
+
CH1  
+
FUSE  
+12V  
MPA 400us  
3/2 Channel Mobile Audio Amplifier with 400 Watts Max. Power  
Amplificateur audio mobile de 400 watts de puissance maximum à 3/2 canaux  
Amplificador Móvil de Áudio de 31 Canales con Potencia Máx. de 400 vatios  
Amplificador Móvel de Áudio de 3/2 Canais com Potência Máx. de 400 Watts  
 
THANK YOU FOR CHOOSING BLAUPUNKT!  
Congratulations! You are the now the owner of an exceptional car audio amplifier from the audio enthusiasts at  
Blaupunkt. Our engineering staff has spent considerable time refining our MPA series amplifiers in order to introduce great  
sound to the consumer at an affordable price. With these products we focus on sonic performance but balanced with  
rugged design and flexible installation.  
Not only do we offer you a great product but also a supportive owners manual. This manual can be used as a teaching  
guide due to its brief, but informative, explanations of amplifier and system design. We are also very concerned about the  
end consumer using proper installation techniques for the highest performance possible from their new audio products.  
MOST important to us are the concerns with safety and the installation process. Since our Blaupunkt retail dealers have the  
tools and experience for an optimized and safe installation, we always recommend they do the final vehicle integration. But,  
should you choose to install these products yourself, please take the time to read this manual completely and abide by all  
precautions.  
WHAT IS AN AMPLIFIER?  
An amplifier, by definition, is a device that receives a small audio signal on its input and reproduces it with larger voltages (or  
current) on its output. Ideally there should be no modifications of the signal other than to make the signal larger either in  
voltage or current levels. If there are changes in the signal character it is considered a "distortion" of the input signal and in  
most cases undesirable. With the added power of an amplifier you can play your system at higher volume levels without  
worrying about such distortions that actually can damage the speakers and your ears (assuming of course that the amplifier  
is NOT grossly over-driven).  
The perfect amplifier will be able to reproduce any output voltage regardless of input signal level. But, infinite output voltage  
is impossible due to upper limits created by the voltages found in a car, typically 12-15 volts DC. In order to achieve  
undistorted power levels beyond about 20 watts per channel a switching power supply MUST be used to step up the  
voltage "rails" inside an amplifier.  
Amplifiers are rated in "watts" of audio output power but there are often references to "rms" power and "MAX" power. Rms  
power is considered as "clean power" since it is undistorted power that is used for reproducing quality sound at all but the  
highest listening levels. "MAX" power is the most power the amp will produce when driven deep into distortion. MAX  
power is considered usable power only by the more "aggressive" listener since the original waveform is so distorted that it is  
uncomfortable to listen to for most people. Regardless of the consumer's listening habits, we dual list these power levels so  
everyone has an understanding of what they are purchasing.  
KEY FEATURES  
Your new Blaupunkt MPA series amplifier, although a simple product, offers some important features. These include:  
"Multi-Mode" operation allowing for combined stereo high-pass/bridged mono subwoofer low-pass output capability.  
2 ohm stability (in non-bridged mode) for paralleling two, 4 ohm speakers.  
RCA inputs (low level) allowing for your typical aftermarket radio signal level outputs.  
Modular inputs (high level) for tapping off of the speaker outputs of a factory radio for example to derive a subwoofer  
signal for an add-on subwoofer speaker system.  
Internal low pass filters for easily deriving a subwoofer system without an add-on crossover that increases system  
complexity and the potential for noise.  
Variable frequency low-pass and high-pass filters (on upper MPA models) for custom tailoring the crossover  
frequency choice for any vehicle.  
Efficient heat-sink design to quickly wick away heat thus ensuring a life time of reliability.  
Simple mounting system for ease of installation.  
3 –  
 
SAFETY CONCERNS  
We always recommend you have your Blaupunkt amplifiers professionally installed but the  
installation process is often so easy that the average consumer can achieve success with little  
trouble. Regardless of the person installing, you should be sure to review the following points  
before proceeding with the installation:  
READ THE MANUAL! Understanding the product and installation limitations before  
lifting a screwdriver.  
WEAR SAFETY GLASSES AT ALL TIMES - Flying debris are always dangerous.  
PROTECT THE VEHICLE - Always disconnect the negative battery cable before  
starting any kind of installation work. This prevents a possible high current electrical  
short (potential fires).  
HEAT - Keep all audio components away from nearby hot vehicle components that heat up over time such as hoses,  
high current wires, and braking system components.  
GIVE YOURSELF LOTS OF TIME - Rushing to complete an installation nearly always ends up with problems.  
DO NOT LISTEN AT HIGH SOUND LEVELS FOR A PROLONGED TIME - these amplifiers, used with high  
efficiency speakers from ANY manufacturer, have the potential to cause permanent hearing loss after listening at  
maximum volume levels for several hours.  
INSTALLATION WARNINGS!  
Before disassembling your beautiful new car you need some basic installation knowledge and skill with common hand and  
power tools. Following such basic installation tips and warnings will prevent possible damage to the vehicle and also  
prevent possible fires.  
AGAIN...READ THE MANUAL! There is a lot of helpful information in this manual that  
will save time and prevent problems later.  
COVER THE VEHICLE WORK AREAS - Use fender covers or blankets to protect the  
work areas from scratches or dings.  
DISCONNECT THE (-) LEAD ON THE BATTERY - No sparks or fires please!  
“REVIEW” THE INSTALLATION - Before using any tools or moving vehicle  
components, take five minutes to review the installation intentions (e.g., verify that an  
amplifier will fit in an area of a car before tearing out all the interior).  
“REVIEW” THE VEHICLE - Before drilling any holes or cutting into any surfaces, make  
sure there are no fuel or hydraulic lines behind the surfaces. Also make sure there are no  
wires routed directly behind or near the desired mounting area (remember...screws can  
often extend 1-2 inches behind the mounting surface).  
ENSURE PROPER FIT - Before cutting or drilling, make sure the amplifier will physically  
fit in its desired location. Check for clearance around rear deck torsion bars or other  
structural elements.  
EVERY CAR IS ASSEMBLED DIFFERENT - Every auto manufacturer uses different  
assembly techniques. Take care in removing/modifying all trim panels and mounting surfaces since they often use  
unique screws or snap fasteners that are difficult to replace if they are lost or broken.  
BE CAREFUL WITH CABLE ROUTING - When routing audio cables, make sure RCA and speaker wires are  
routed away from high current power lines for audio amplifiers and vehicle systems lines when possible. This will  
help prevent noises from creeping into the audio system, plus prevent potential damage to the vehicle wiring itself.  
BE CAREFUL WITH ALL CONNECTIONS - When making connections, make sure each connection is clean  
and properly secured. Observe all polarity markings carefully to ensure proper end performance.  
CAUTION - FUEL TANKS AND FUEL LINES ARE NOW LOCATED DIRECTLY BENEATH THE REAR  
DECK IN MANY CARS - CHECK FOR ADEQUATE CLEARANCE BEFORE EVEN CONSIDERING  
SUCH A MOUNTING LOCATION!  
4 –  
 
SYSTEM PLANNING  
Before wiring up an audio system that may not achieve the  
sound quality you want, be sure to choose a system concept  
that fits your listening requirements. Basic systems, a  
receiver with internal 4x20 watts and 4 coax speakers, are  
adequate for many listeners. But, when you want to really  
“feel” the music, you will need some kind of subwoofer  
amplifier/speaker combination. Although many people might  
jump into an “add-on” amplifier to power to rear coaxial  
speakers, a better choice is usually a subwoofer  
Full-Range  
Full-Range  
amp/speaker system that supplements the existing 4 speaker  
system as shown in the adjacent drawing. Such a system  
provides a surprising improvement in sound quality due to  
the usually dramatic increase in bass response.  
Subwoofer  
Full-Range  
Full-Range  
The next dramatic step up in performance is with a “multi-  
channel” system that offers more dynamic range in the mids  
and highs due to higher power plus more bass response due  
to multiple woofers and/or more power. But, with such a  
system, the stereo image and overall listening experience  
usually becomes much more life-like due to better tonal  
quality midrange/tweeter speakers and usually better  
placement.  
Supplementary subwoofer system  
Tuner  
Passive X-over  
Sat Amplifier (4x50 W)  
To build such a system though, complexity goes up due to  
the addition of passive or active crossovers which take time  
to install and may inject noise into the system due to potential  
noise signal pick up. The results though of such a system  
can be dramatically pleasing.  
Sub Amplifier (2x100 W) Subwoofers  
High performance multi-channel system  
INSTALLATION TOOLS  
For most installations, simple hand tools are adequate to install an aftermarket amplifier. Depending upon the mounting  
locations used, you will need power tools for drilling and cutting plastics and metal. A good starting list is summarized  
below:  
Tape measure and ruler  
Marking pen and starting punch  
Phillips and flat blade screwdrivers (small and medium sizes)  
Nylon wire bundle ties  
Pliers: standard vice-grip and needle nose styles  
Light-duty trim pry-bar for removing door trim  
Cutting shears or nibbling tool for cutting thin and medium gauger metal  
Wire cutters, wire strippers, electrical tape, crimping pliers and appropriate crimp-on  
terminals  
Power drill with appropriate sized drill bits  
5 –  
 
VEHICLE WIRING  
VEHICLE FUSING  
SYSTEM FUSE CHART  
For safety purposes, a high current fuse (or circuit breaker)  
MUST be installed in line with the amplifiers(s) immediately at  
the battery to prevent vehicle damage should the battery line  
in advertently shorted to the vehicle chassis. The chart at the  
right shows the recommended master fuse sizes for an  
average audio system with noted “rms” output power levels.  
(Fuse size for total amplifier system power in “rms” watts)  
100 W  
200 W  
500 W 1000 W  
Fuse Size  
(in amps)  
20 A  
30 A  
50 A  
100 A  
POWER WIRING  
SYSTEM POWER AND GROUND WIRE CHART  
Most vehicles built since 1990 have adequate current  
capability for your amplifier. Except for systems above about  
500 W rms, the factory charging system and battery should  
easily support it if properly installed. Proper wire size must  
be chosen to ensure adequate current delivery to the amp.  
Wire size (gauge) of the cables need to increase in size for  
higher power systems. (Wire sizes larger than those noted  
are usually a waste of time and money since they offer Little  
or no performance improvements.)  
(Wire gauge for total system in 'rms' watts)  
WIRE LENGTH  
5 ft. / 1.5 m  
100 W  
12  
200 W  
500 W 1000 W  
10  
10  
8
8
8
6
6
4
4
10 ft. / 3.0 m  
15 ft. / 4.5 m  
20 ft. / 6.0 m  
25 ft. / 7.5 m  
12  
4
10  
2
2
10  
8
Wire diameter must increase (decreased wire gauge number)  
for higher power systems. For long wire runs the wire  
diameter must also increase. The wire sizes noted allow for a  
maximum 0.5 volts DC drop over the give wire run which  
results in Sound Pressure Level drops inaudible to the  
average listener.  
10  
8
0 or 00  
SPEAKER WIRING  
LOUDSPEAKER WIRE CHART  
(Wire gauge per loudspeaker/speaker power in “rms” watts)  
As with power wire, speaker wire size (gauge) changes with  
the power required and the length of the wire run. The  
speaker wire chart shows the minimum recommended wire  
size for a single audio output channel driving a loudspeaker  
at a given distance with a maximum power loss of 0.5 dB,  
the threshold of audibility. (Wire sizes larger than those noted  
are usually a waste of time and money since they offer little or  
no performance improvements.)  
WIRE LENGTH  
5 ft. / 1.5 m  
20 W  
18  
50 W  
16  
100 W  
16  
200 W  
16  
10 ft. / 3.0 m  
15 ft. / 4.5 m  
20 ft. / 6.0 m  
25 ft. / 7.5 m  
18  
16  
16  
16  
16  
16  
16  
14  
16  
16  
16  
14  
16  
16  
14  
12  
FINAL VEHICLE WIRING  
Current requirements for an upgraded audio system dictate a  
dedicated power line be run from the amplifier directly to the  
battery of the vehicle. This line should NOT be run to the  
fuse panel of the vehicle but directly to the battery. DO NOT  
run to the alternator either. There MUST be a fuse installed at  
the battery with adequate amperage as shown in the chart  
above.  
Battery  
Battery  
Connector  
Fuse or  
Circuit  
Breaker  
Grommet  
To prevent  
damage to  
power wire  
Radio  
Power Wire  
(10 gage  
wire or  
As for the final signal wiring, be sure to route the audio cables  
down the side of the car opposite the power lines to avoid  
noise pick up from the lines. Also, try to route all audio  
cables away from noise sources such as engine computers  
and ABS brake computers.  
larger)  
Power Antenna  
Turn-On Wire  
(18-20 gage wire)  
Speaker Wires  
or  
RCA Cables  
Proper power grounding is important to insure adequate  
current flow. Be sure to grind the surface clean of all paint to  
ensure a solid electrical connection.  
Speakers  
Amplifier  
Ground Screw  
Drill 1/8” hole in  
chassis sheet metal  
Use the same ground if  
using multiple amplifiers  
6 –  
 
INPUTS & CONTROLS  
1 2 3 4 5 6 7 8 910  
The inputs and controls for this amplifier are explained in the summaries below and reference the numbered call-outs above.  
1.) LOW-PASS CROSSOVER CONTROL (ch 1 & 2) - Once the “crossover  
frequency setting” is set to “LOW-PASS”, this control adjusts the frequency  
for which all signals BELOW this setting are passed on to the speakers.  
"Floating Ground" Radio Outputs  
2.) HI-PASS CROSSOVER CONTROL (ch 1 & 2) - Once the “crossover frequency  
HIGH-LEVEL – INPUT  
setting” is set to “HI-PASS”, this control adjusts the frequency for which all  
signals ABOVE this setting are passed on to the speakers.  
GAIN  
R
+
-
-
+
L
3.) CROSSOVER FREQUENCY SETTING (ch 1 & 2) - the internal crossover  
frequency control setting of the amplifier can be switched to either the “flat”  
frequency response position or in a high-pass/low-pass mode. On this  
amplifier, the choice is for either 50-250 Hz in LOW-PASS mode or 50-500 Hz  
in a HIGH-PASS mode.  
MAX  
MIN  
GREEN  
LEFT (+)  
LEFT (–)  
GREEN-BLACK  
(NOT USED)  
4.) HIGH LEVEL INPUTS - Should RCA cables not be available from the radio you  
are able to tap onto the audio signal from the high level speaker outputs of the  
radio. This is most commonly used when the amp is an add-on device such  
as for a subwoofer system.  
GREY-BLACK  
RIGHT (–)  
RIGHT (+)  
GREY  
5.) INPUT GAIN CONTROL (ch 1 & 2) - This controls the gain setting on the input of  
the amplifier. For high gain settings ( 0.3 volts), this says that it takes ONLY  
0.3 volts to drive the amp to full output. For low gain settings (near 4 volts),  
this says that it takes nearly 4 volts to drive the amp to full output. If the amp  
is often going into distortion at only moderate volume settings on the radio,  
rotate this control towards the 4 volts setting to reduce the distortion.  
"Common Ground" Radio Outputs  
HIGH-LEVEL – INPUT  
GAIN  
R
6.) LOW LEVEL INPUTS - The more commonly used inputs, these are connected to  
the standard RCA outputs available on nearly all aftermarket radios today.  
These lines are dedicated to left and right outputs of the radio, be it for front or  
rear speaker installations. The input gain settings of the amplifier (0.3 - 4  
volts) are referenced to these inputs.  
+
-
-
+
L
MAX  
MIN  
7.) INPUT GAIN CONTROL (ch 3) - This controls the gain setting on the input of the  
amplifier. For high gain settings ( 0.3 volts), this says that it takes ONLY 0.3  
volts to drive the amp to full output.  
GREEN  
LEFT (+)  
GREEN-BLACK  
(NOT USED)  
RADIO CHASSIS GROUND -OR-  
COMMON SPEAKER GROUND  
8.) CROSSOVER FREQUENCY SETTING (ch 3) - the internal crossover frequency  
control setting of the amplifier can be switched to either the “flat” frequency  
response position or in low-pass mode, 50-250 Hz.  
GREY-BLACK  
(NOT USED)  
RIGHT (+)  
GREY  
9.) POWER “ON” LED - This light will turn on when the amplifier receives a +12 volt  
turn on signal from the radio in the vehicle. The input line to the “trigger”  
connection must be properly connected to the radio’s trigger line which is  
High Level (Speaker Input) Wiring  
often also the power antenna line. If the amp is properly wired, but the light does not turn on, verify the trigger line is properly  
connected, is receiving +12 volts, and the speaker outputs are not shorted to themselves or ground in any way.  
10.) LOW-PASS CROSSOVER CONTROL (ch 3) - Once the “crossover frequency setting” is set to “LOW-PASS”, this control adjusts the  
frequency for which all signals BELOW this setting are passed on to the speakers. The power and speaker connections for this  
amplifier are explained in the summaries below and reference the numbered call-outs above.  
7 –  
 
POWER CONNECTIONS & SPEAKER OUTPUTS  
1
2 3  
Power Terminal (+12V)  
1.) POWER CONNECTIONS -  
GROUND - This is the high current ground connection to  
the chassis of the car. It should be fastened to a clean  
ground connection in the car, capable of handling high  
current loads and within 3 feet (absolutely no longer than 3  
feet).  
Connect directly to the vehicle battery  
+ terminal with 10 gage wire (minimum)  
+12V  
TRIGGER - This allows the amp to be remotely switched  
on from the radio and normally uses a dedicated “trigger”  
line output. If one is not available, simply use the power  
antenna line. When a +12 volt DC signal is applied it will turn  
on the amplifier.  
+12V - A high current line run directly to the battery is  
required. This line should NOT be connected to the fuse  
block of the vehicle. It MUST be fused through its own  
dedicated fuse at the battery.  
Spade  
Connector  
NOT SUPPLIED  
30 amp Fuse  
To Battery  
or Circuit Breaker  
Terminal  
Battery  
Terminal  
Adapter  
10 Gage  
Wire  
2.) FUSE - This fuse is only for catastrophic situations should the  
amplifier begin to self-destruct or incur installation situations  
where gross amounts of current are being required from the  
amplifier. Although another fuse is located at the battery, in  
line with the battery high current line, this fuse MUST remain  
in the circuit to physically protect the amplifier.  
Ground Terminal  
Connect to a good chassis ground. The  
ground connection should be clean,  
unpainted metal to provide a good  
electrical connection.  
+12V  
3.) SPEAKER OUTPUT CONNECTIONS - These  
connections are used to connect to the loudspeakers with  
the appropriate impedance. It is imperative that these lines  
NOT be connected or touch the chassis of the vehicle in any  
way. Also, the (+) and (-) leads are in no way inner  
Sheet  
Metal  
Spade  
Screw  
Connector  
Ring  
Connector  
connected so the left channel (+) and the right channel (+)  
must remain independent. In addition, the (-) leads for the  
speakers CANNOT touch or be wired to the ground lead of  
the amplifier; these are NOT common ground amplifiers.  
10 Gage  
Wire  
Drill 1/8” hole  
in chassis  
sheet metal  
Remote Terminal  
Connect the radio power antenna lead from  
the receiver to the amplifier  
terminal.  
This turns the amplifier on whenever the  
receiver is turned on.  
+12V  
Important  
If wiring connections are made wrong, the  
unit will not operate properly and it could be  
damaged. Follow the installation  
instructions carefully, or have the installation  
handled by an experienced technician.  
Spade  
Butt  
Connector  
Connector  
(not supplied)  
To Receiver  
Power  
Antenna Lead  
18-20 Gage  
Wire  
8 –  
 
SYSTEM CONFIGURATION #1  
Full-Range  
High-Pass  
Subwoofer  
Full-Range  
High-Pass  
3 Channel Multi-Mode (Active)  
Speakers  
+ CH2 –  
+ CH1 –  
+ CH3 –  
CROSSOVER  
LOW FLAT HI  
SUBWOOFER  
+
Bridged  
OFF  
ON  
This amplifier offers a very unique installation advantage by including 3 independent amplifier channels with 2 active  
crossover sections. The inputs require only 2 signal leads (left and right) and derive the bass signal from these two.  
The final installation is most commonly configured with the two stereo channels driving satellite speakers in the flat or high-  
pass mode for maximum sound pressure level. Such a system design supports an installation where the head unit (with  
internal power) drives the front speakers and this amp drives the rear satellite speakers along with the outboard subwoofer.  
The result of such a system is a very pleasant, and dynamic sound system without acoustical “strain” (distortion) at high  
sound levels.  
9 –  
 
SYSTEM CONFIGURATION #2  
Full-Range  
Full-Range  
Subwoofer  
Full-Range  
Full-Range  
2 Channel Dual Subwoofer Mode  
Speakers  
+ CH2 –  
+ CH1 –  
+ CH3 –  
CROSSOVER  
LOW FLAT HI  
SUBWOOFER  
+
Bridged  
OFF  
ON  
The largest improvement in sound quality always comes when adding some kind of subwoofer via a dedicated subwoofer  
amplifier and electronics crossover. The electronic crossover ensures minimal overlap of the bass response with the mid  
and high frequencies from the other speakers resulting in a more accurate performance compared to conventional coaxials  
with additional power.  
By installing this amplifier in the stereo mode, you are able to drive two subwoofer speakers and in to low impedance loads  
(e.g., 2 ohms) without over heating the amplifiers. Also, such an installation more easily supports a standard 2 speaker  
woofer box that may already be constructed. Since two woofers can play 6 decibels louder than one at a given power (due  
to acoustical laws of “mutual-coupling”), the resulting sound pressure level is substantial. This is probably the most  
common use for a conventional two channel amplifier there is.  
10 –  
 
TROUBLE-SHOOTING GUIDE  
Below is a basic trouble-shooting guide to assist in seeking out and correcting a problem that may occur in the installation  
process. Although lengthy, this chart cannot address every single problem possible but mainly the ones most common.  
SYMPTOM  
PROBABLE CAUSE OR CORRECTION  
No power (power light not on)  
Check connections to amps +12 volt, ground, and remote lines.  
Use voltmeter to verify voltages are at terminals of amp.  
Check main power connection at battery.  
Check fuse in power line at battery.  
Disconnect all speakers but not power lines - if unit then turns on, a speaker short  
or speaker line touching vehicle chassis is likely.  
Power but no sound (power light is on)  
No sound from one channel or entire side  
Very low sound level  
Check all input cable lines for connection.  
Disconnect speakers from amp, test speaker lines with digital voltmeter to verify >2  
ohms per channel (non-bridged mode).  
Check radio’s balance and fader control positions - verify they are at center.  
Check speaker connections at amp and speaker.  
Check input leads for connection to amp.  
Verify radio balance and fader controls are at center positions.  
Check amplifier’s input gain control setting - adjust for higher output levels if  
necessary (gain settings closer to 0.3 volts).  
Receiver may have very low output voltage levels - a step up “line driver” may  
have to be used.  
Power amplifier turns on and off repeatedly  
(motor-boating sound)  
Make sure power connections at batter are tight.  
Verify battery voltage is >11.5 volts DC (12.5-15V engine on) at amplifier with engine off.  
Check all radio and amplifier ground connections.  
Amplifier turns off during loud or distorted  
passages  
Input stage being over-driven - lower input gain (closer to 4 volt setting).  
Verify battery voltage is >11.5 volts DC at amplifier with engine off.  
Check all radio and amplifier ground connections.  
Verify speaker loads >2 ohms on all channels (non-bridged mode).  
Amplifier performs fine but gets very hot to  
the touch  
Input gain control too high - lower accordingly (closer to 4.0 volt setting).  
Verify speaker loads >2 ohms on all channels (non-bridged mode).  
Verify the mounting location allows for free air movement around the amp.  
Preferably, the amp should be mounted with fins up and down so rising heat moves  
quickly away from amp.  
Amplifier turn-on/turn-off pops or noises  
“turn on race” - disconnect trigger from radio and turn on/off via a wire jumper to  
power terminal. If noise goes away, the radio is turning on/off too slowly. This is  
radio problem and can only be corrected with outboard turn-on delay relay system.  
Radio “thump” - disconnect the RCA input lines to the amp and turn on/off via radio  
trigger. If noise goes away without RCA lines connected, the radio is sending pops  
out through RCA lines. This is a radio problem and can only be corrected with  
outboard turn-on delay relay system.  
Cracking noises on AM/FM radio but not  
on tape or cd.  
Ensure the problem is “radiated noise” by placing a portable FM radio near the car  
engine. If noise is picked up, then it is a vehicle problem and not your system.  
Research to isolate the source and properly shield or bypass.  
Are spark plugs and wires > 3 years old? These can often radiate substantial noise  
when old.  
Verify the engine block has a good ground connection to chassis ground.  
Verify the engine compartment hood is grounded to vehicle chassis via a braided  
grounding strap.  
Whining noise, engine running, varies in  
pitch or loudness with engine speed, AND  
varies with radio volume control setting  
(this is generally a RADIO installation  
problem)  
Verify all power and ground connections are clean at radio.  
Re-route radio power and ground so they are sourced from same connections back  
at amplifier (this is called a “common” ground).  
Check all ground connections to ensure clean surfaces that have all paint removed  
and also not oxidation buildup over time.  
Verify there is some kind of power filtering choke assembly at back of radio. If not,  
install one.  
Whining noise, engine running, varies in  
pitch or loudness with engine speed, BUT,  
DOES NOT vary with radio volume control  
setting (this is generally an amplifier  
installation problem)  
Check battery ground connections at chassis are clean and tight, scraped free of  
oxidation, paint, and grease.  
Re-route radio power and ground so they are sourced from same connections back  
at amplifier (this is called a “common” ground).  
Bypass all equipment between radio and amp (e.g., equalizers) directly connecting  
radio. If noise goes away, signal processor has problem.  
Check for signal level “ground loops” - disconnect the outer shield of the RCA cable  
at one end of the cable (e.g., radio end). If noise goes away, modify cables  
accordingly. There are voltage differences at the ground connections of the  
components and these are NOT correctable any other way than such shield cutting  
or an outboard “ground loop isolator” which is a small transformer.  
11 –  
 
LIMITED WARRANTY INFORMATION (UNITED STATES ONLY)  
Robert Bosch Corporation warrants new Blaupunkt car audio products it distributes in the United States through authorized Blaupunkt  
dealers, or which are imported as original vehicle equipment by the automobile manufacturer, to be free from defects in material and  
workmanship, in accordance with the following:  
For twelve (12) months after delivery to you, the original consumer purchaser, we will repair or at our option replace at no charge to you  
any car audio product which, under normal conditions of use and service, proves to be defective in materials or workmanship.  
However, this warranty does not cover expenses incurred in the removal or reinstallation of any car audio product, whether or not  
proven defective, and does not cover products not purchased from an authorized Blaupunkt dealer. This warranty is limited to the  
original consumer purchaser and is not transferable. Repaired and replacement car audio products shall assume the identity of the  
original for purpose of this warranty and this warranty shall not be extended with respect to such products.  
To obtain performance of this warranty, contact the nearest Blaupunkt authorized repair facility or our nearest office. A dated purchase  
receipt or other proof that the product is within the warranty period will be required in order to honor your claim. Carefully pack the unit  
and ship prepaid to the servicing location. For further information, write to the Robert Bosch Corporation, 2800 South 25th Avenue,  
Broadview, Illinois, 60153, attention Blaupunkt Customer Service Department or call 1-800-266-2528.  
Specifically excluded from this warranty are failures caused by misuse, neglect, abuse, improper operation or installation, dropping or  
damaging, unauthorized service or parts, or failure to follow maintenance instructions or perform normal maintenance activities.  
Normal maintenance activities for car audio products include but are not limited to cleaning and other minor maintenance activities and  
adjustments that are outlined in the owner's manual or that are normally required for continued proper operation. Also excluded from  
this warranty is the correction of improper installation and the elimination of any external electromagnetic interference. This warranty  
sets forth your exclusive remedies with respect to the products covered by it. We shall not be liable for any incidental, consequential,  
special or punitive damages arising from the sale or use of any Blaupunkt car audio products, whether such claim is in contract or tort.  
No attempt to alter, modify, or amend this warranty shall be effective unless authorized in writing by an officer of Robert Bosch  
Corporation.  
THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES OR REPRESENTATIONS, EXPRESS OR IMPLIED, INCLUDING ANY  
WARRANTY IMPLIED BY LAW, WHETHER FOR MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE OR OTHERWISE  
AND SHALL BE EFFECTIVE ONLY FOR THE PERIOD THAT THIS EXPRESS WARRANTY IS EFFECTIVE.  
In the event any provision, or any part or portion of this warranty shall be held invalid, void or otherwise unenforceable, such holding  
shall not affect the remaining part or portions of that provision or any other provision hereof.  
NOTICE TO CALIFORNIA OWNERS: If your Blaupunkt car audio product needs warranty repair service and there is no authorized  
service center reasonably close to you, you can return the defective unit to the dealer from whom you purchased it, or you can return it  
to any dealer who sells Blaupunkt car audio products. The dealer may, at the dealer's option, replace, repair or refund the purchase  
price for any Blaupunkt car audio products which prove defective under conditions of normal use. If the dealer fails to repair, replace, or  
partially refund your money, you may take your Blaupunkt car audio product to any repair shop and they can repair your unit at our  
expense unless the repair cost exceeds the depreciated value of the unit, but you must contact Blaupunkt to receive authorization to  
do this before your car audio product is repaired.  
ROBERT BOSCH CORPORATION  
BLAUPUNKT CUSTOMER SERVICE  
2800 SOUTH 25TH AVENUE  
BROADVIEW, IL 60153  
TEL: 1-800-266-2528  
BLAUPUNKT TECHNICAL SUPPORT  
These amplifiers are designed to install quickly and easily into most vehicles. Should you experience installation problems,  
we will make all reasonable efforts to help you, the end purchaser or Installation Technician, to competently install these  
components. Before calling us please carefully review this owners manual for  
the answers to your questions.  
Due to the limited print space of this owners manual, we also offer additional  
information regarding installation and systems on our Internet site. Via a  
standard Internet connection through a local Internet Service Provider or other  
providers (e.g., America Online), connect to our web site at the following  
on system design, vehicle integration, product fit guides where possible, and  
extensive information on loudspeaker design and installation. For the more  
adventuresome builder, we also offer our “BlauBox” computer program which  
assists in designing subwoofer enclosures. This program is FREE to down load  
and use. We also “link out” to other sites that provide additional theory and  
technical support for the consumer and the technically interested.  
12 –  
 
Robert Bosch Corporation  
Sales Group - Blaupunkt Division  
2800 S. 25th Avenue, Broadview, Illinois 60153 U.S.A.  
Copyright 1998 by the Robert Bosch Corporation  
No portion of this work may be reproduced in any form without the written consent of the Robert Bosch Corporation  
Printed in China (8/98)  
 

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