Optimus XL-50 User manual

XL-50 Trunk-Mount Stereo Amplifier
(120-2013) Features Faxback Doc. # 40181
Your Optimus XL-50 High-Power Trunk-Mount Stereo Amplifier produces a
total of 50 watts to give added punch and power to your vehicle's existing
autosound system.
The amplifier produces up to 25 watts per channel of clean, powerful sound
at all audio frequencies with minimum distortion. You can connect your
autosound system's low-level or speaker-level outputs to this amplifier.
Its features include:
14K Gold-Plated Speaker Terminals - designed for low impedance, high
conductivity, and minimum corrosion, to provide the highest
signal transfer and lowest sound distortion.
High- or Low-Level Input Signal-Compatible - accepts either high-level
(speaker) or low-level (preamplifier) input signals, to
match your stereo system's output for the best
performance.
Input Level Control - lets you adjust the level of the audio signals that
enter the amplifier.
Automatic Power Switching - can automatically turn the amplifier on or off
when you turn your autosound system on or off
(depending on how you hook up the amplifier).
Power Indicator - lights when power is supplied to the amplifier.
Short Circuit Protection - distorts the amplifier's sound if any output
channel shorts, alerting you to turn off the
autosound system.
Auto-Off - protects the amplifier by temporarily shutting down if it gets
too hot, an output channel shorts, or it detects an input
overload. The amplifier restarts automatically when it cools or
the problem is corrected.

XL-50 Trunk-Mount Stereo Amplifier
(120-2013) Preparation Faxback Doc. # 40182
SUPPLIED HARDWARE
Your amplifier comes with the following items. Be sure you locate
everything before you store or dispose of the packing materials.
Fuse 7.5A
Power Wire (Red) (1)
Ground Wire (Black) (1)
Remote Wire (Blue/White) (1)
4-Pin Connector with Wire (1)
Sheet Metal Screws (4)
Flat Washers (4)
Lock Washers (4)
Twist-On Terminal Connector (4)
BEFORE YOU BEGIN THE INSTALLATION
Before you install your amplifier, read all the instructions. And you
should be able to answer all of these questions about your vehicle's
electrical and autosound systems.
Does my vehicle have an autosound system, such as a car stereo or CD
player, already installed? (You must have an existing autosound system
to use this amplifier.)
How do I connect a wire to the fuse box?
Which of the autosound system's wires is the power wire?
Which of the autosound system's terminals are low-level outputs and which
are high-level (speaker) outputs?
Also, be aware that installation in your vehicle might require cutting or
modifying your vehicle.
Choosing a Mounting Location
A good location for mounting the amplifier is in your vehicle's trunk.
Wherever you decide to mount it, choose a mounting location that:
Does not interfere with the vehicle's operation.

Lets you drill mounting holes without damaging other vehicle components.
Allows enough space around the cooling fins for proper airflow and
cooling.
Lets you easily see the amplifier's POWER indicator.
Warning: The amplifier gets very hot while it is on. Do not touch the
amplifier or place flammable objects near it while it is on.
Preparing the Mounting Area
Before you mount the amplifier, make sure you have all the materials you
need, such as an adapter harness, additional wire, shielded audio cables,
and 16- or 18-gauge marked or color-coded wires.
Then confirm that the amplifier fits in your vehicle's available mounting
area. This amplifier requires a 5 1/2-inch high by 9 3/4-inch wide by
6-inch deep (13.9 x 23.5 x 15.3 cm) mounting area.
Routing Cables and Wires
Avoid routing the connection cables and any speaker wires near moving parts
or sharp edges. You can usually route wires and cables along the wiring
channel beneath the vehicle's door facings by carefully removing the
molding that holds the carpet in place. After routing the cables and wires,
replace the molding.
INSTALLATION ORDER
For trouble-free installation, simply follow the instructions in order.
First, make all the connections temporarily by connecting the amplifier to:
1. Ground and power.
2. Your autosound system's outputs.
3. Your speakers.
Then test the connections. When you confirm that everything works as
expected, disconnect the amplifier, mount it in your vehicle, and reconnect
it.
Caution: If you do not make the connections in the order shown, damage
to the amplifier and your autosound system is possible if any
wire connections are made incorrectly.

Note: For easier installation, mark each wire you plan to connect with the
name of the terminal you will connect it to.
BEFORE YOU MAKE THE CONNECTIONS
The supplied connection cables include all the lead wires you need to
connect the amplifier to ground, power, and your existing autosound system.
Important:
Do not cut these wires. If you cut any wire, you cannot obtain a refund
or exchange on this product. However, RadioShack will provide warranty
service if you cut a wire and find the product is defective.
If the connectors on your vehicle's autosound system are not compatible
with the amplifier's connectors, you might need an adapter harness to
complete the connections. RadioShack stores sell adapter harnesses for
most vehicles.
You might need additional wire, depending on your individual autosound
system, to complete the connections. Your local RadioShack store carries
a full line of wire and wire management accessories.
Cautions: For added safety and to protect your amplifier and autosound
system, disconnect the cable from your vehicle's negative (-)
battery terminal before you begin.
Be sure your speakers can handle as much as 50 watts of power
(25 watts per channel). Each speaker must have an impedance of
at least 4 ohms. Your local RadioShack store carries a full line
of speakers.
To make it easier to gauge wire length and connect the amplifier,
temporarily place the amplifier as close as possible to the selected
mounting location.
CONNECTING GROUND AND SWITCHED/PRIMARY POWER
Follow these steps to connect the amplifier to ground, switched power, and
primary power.
1. If you have not done so already, disconnect the cable from your
vehicle's negative (-) battery terminal.
2. Use a screwdriver to connect the spade end of the supplied black ground
wire to the amplifier's GND (ground) terminal.

3. Connect the black ground wire's other end to a chassis ground, such as
a metal bolt attached to a metal part of the vehicle's frame. Be sure
the bolt is not insulated from the chassis by a plastic part.
4. Use a screwdriver to connect the spade end of the supplied blue/white
wire to the amplifier's REM (remote power) terminal.
5. Connect the blue/white wire's other end to your autosound system's
switched power lead using one of the supplied twist-on terminal
connectors.
This connection turns on the amplifier when you turn on the autosound
system, and turns off the amplifier when you turn off the autosound system.
This prevents your vehicle's battery from being drained if you leave your
amplifier on when you turn your autosound system off.
If your autosound system does not have a switched power lead, connect the
blue/white wire's other end to a point in your vehicle's fuse block that
has power only when you turn on the ignition or turn the key to ACC.
This connection turns on the amplifier when you turn on the ignition or
turn the key to ACC, and turns off the amplifier when you turn off the
ignition. This prevents your vehicle's battery from being drained if you
leave your amplifier on when you turn your autosound system off.
6. Use a screwdriver to connect the spade end of the supplied red power
cable (with in-line fuse holder) to the amplifier's +12V terminal.
7. Connect the other end of the red power cable to your vehicle's positive
(+) battery terminal.
Caution: Due to the amplifier's high current requirement, you must connect
the red power cable's fused end directly to the vehicle's positive
(+) battery terminal or damage to your vehicle's wiring could
result.
Do not reconnect your vehicle's negative (-) battery cable yet.
CONNECTING INPUTS
Preparing the Speaker Wires
You can connect two or four speakers to the amplifier and your autosound
system.

Caution: You must connect a separate wire to each speaker terminal as
described in the following procedures. Do not use a common wire
or chassis ground for any speaker connection.
Notes:
We recommend you use 16- or 18-gauge marked or color-coded wires to help
you correctly connect the speakers to your amplifier.
Color-coded wires have a stripe running down one of the conductors or
different colored insulation for each conductor. Your local RadioShack
store has a wide selection of speaker wire to choose from.
For the maximum bass response and the best overall performance, keep
your speakers properly phased (connect + to + and - to -).
1. With the speakers placed in their approximate locations, run one wire
from each speaker to the amplifier.
2. Separate each wire's two conductors at both ends for a length of about
4 inches.
3. Strip the insulation from the ends of each conductor to expose 1/4 inch
of wire. Twist the ends to secure loose strands.
LOW-LEVEL INPUTS
You can connect your autosound system's low-level line out jacks to the
amplifier's LOW INPUT jacks.
If your autosound system does not have low-level line out jacks, see
"High-Level (Speaker Wire) Inputs" to connect your amplifier.
Note: For the best results, use shielded audio cables such as Cat. No.
# 42-2356 (not supplied).
1. Temporarily place the amplifier as close as possible to the selected
mounting location.
2. Connect one end of a shielded audio cable to the autosound system's
left line out jack.
3. Connect the other end of the cable to the amplifier's LOW INPUT LEFT
jack.
4. Repeat steps 2 and 3 to connect the autosound system's right line out

jack to the amplifier's LOW INPUT RIGHT jack.
HIGH-LEVEL (SPEAKER WIRE) INPUTS
If your autosound system does not have low-level line out jacks but has
only speaker outputs, connect your autosound system's speaker outputs to the
amplifier's HIGH INPUT jacks.
Note: A floating ground connection lets the amplifier provide more power
to each speaker, but requires that you connect a separate wire to
each speaker terminal. A common ground connection lets you use
fewer wires to connect the speakers to the amplifier, but reduces
the amount of power supplied to the speakers from the amplifier.
Use the supplied wire harness and the supplied twist-on terminal connectors
to make the appropriate connections.
CONNECTING SPEAKERS
1. Use a screwdriver to connect the left speaker's positive (+) wire to
the amplifier's SPEAKER L (+) terminal.
2. Use a screwdriver to connect the left speaker's negative (-) wire to
the amplifier's SPEAKER L (-) terminal.
3. Repeat steps 1-2 to connect the right speaker's positive (+) and
negative (-) wires to the amplifier's SPEAKER R (+) and SPEAKER R (-)
terminals.
COMPLETING THE INSTALLATION
Testing the Connections
Before you continue, make sure you have securely made all connections.
Then reconnect the cable to the vehicle's negative (-) battery terminal.
Turn on your vehicle's ignition and autosound system to confirm that the
amplifier and autosound system operate properly and that the speaker's
sound is not muffled. The amplifier turns on after a few seconds.
If you cannot quickly confirm whether the autosound system and amplifier
are working properly, turn off your vehicle's ignition and disconnect the
cable from your vehicle's negative (-) battery terminal. Then recheck
your connections.
After you test the autosound system and amplifier and verify that everything

is properly connected and working, follow the instructions in "Mounting
the Amplifier."
Mounting the Amplifier
Once you verify that the amplifier is connected properly, follow these
steps to mount it.
1. Disconnect the cable from the vehicle's negative (-) battery terminal.
2. To make mounting more convenient, temporarily disconnect the
amplifier's connections (ground, primary power, remote power, your
autosound system's input, and speakers).
Note: If you have not already done so, be sure to mark each wire with
the name of the terminal you will reconnect it to.
3. Using the mounting holes on the amplifier as a guide, mark the positions
for the mounting holes.
4. Drill 9/64-inch (3.57 mm) holes at the marked locations, being careful
not to damage anything behind the mounting surface.
5. Secure the amplifier to the mounting surface using the supplied sheet
metal screws and washers.
6. Reconnect the wiring.
7. Reconnect the cable to the vehicle battery's negative (-) terminal.
8. Reset your vehicle's clock, your autosound system's tuner memory, and
other timer/memory devices.

XL-50 Trunk-Mount Stereo Amplifier
(120-2013) Operation Faxback Doc. # 40183
Turning on the Amplifier
The amplifier automatically turns on a few seconds after you turn your
vehicle's ignition switch to ACC or ON or turn on your autosound system,
depending on how you wired the system. The POWER indicator on the side of
the amplifier lights when the amplifier is on.
Important: Your amplifier requires 5 amps or more of power from your
vehicle's battery during operation. To protect you battery
from discharging, do not operate the amplifier unless your
vehicle is running.
Note: Your amplifier temporarily shuts down if it gets too hot, then
restarts automatically once it cools.
Adjusting the Audio Level
For the best performance, you must set LEVEL (MIN/MAX) on the amplifier to
adjust the level of the audio signals that enter the amplifier.
1. Use a screwdriver to turn LEVEL (MIN/MAX) fully counterclockwise to
MIN.
2. Turn up the autosound system's volume control to about one-third of its
full range.
3. Adjust LEVEL (MIN/MAX) to a comfortable listening level.
4. Turn up the autosound system's volume control until the sound begins to
distort. Then immediately turn the volume down to a point just before
where the distortion just before where the distortion began.
Caution: Never turn up the autosound system's volume control more than
needed to adjust the audio level, or more than two-thirds of
its maximum volume.
5. Adjust LEVEL (MIN/MAX) until the sound is at the maximum level you want
the amplifier to produce.
6. Adjust the autosound system's volume control to a comfortable listening
level.

XL-50 Trunk-Mount Stereo Amplifier
(120-2013) Troubleshooting Faxback Doc. # 40184
We do not expect you to have any problems with your Optimus XL-50 High-
Power Trunk-Mount Stereo Amplifier, but if you have a problem, this chart
might help. If not, take the amplifier to your local RadioShack store for
assistance.
SYMPTOM POSSIBLE CAUSE SUGGESTION
No power - the Power problem. Check the amplifier's and
amplifier's POWER autosound system's fuses
indicator does not and replace them if
light after the necessary.
vehicle's autosound
system is turned on. Vehicle's ignition not Start the vehicle or set
turned on or set to ACC. the key to ACC.
Amplifier not connected Check all connections.
to autosound system/
vehicle correctly.
No sound. Autosound system not Turn the autosound system
turned on or volume on or adjust its volume.
set to minimum.
Amplifier's LEVEL Adjust LEVEL (MIN/MAX).
(MIN/MAX) control to
set to minimum.
Amplifier not connected Check all connections.
to autosound system/
vehicle correctly.
The amplifier might Turn your autosound system
have shut down. off and let the amplifier
cool. Make sure the
amplifier is properly
ventilated. The amplifier
will turn itself back on
when it cools. Then, turn
your autosound system back
on.

An output channel might
have shorted. Take the
amplifier to your local
RadioShack store.
The amplifier detected
an input overload. Reduce
the autosound system's
volume.
Power problem. Check the amplifier's and
autosound system's fuses
and replace them if
necessary.
Distorted sound. The amplifier might be Reduce your autosound
receiving too much system's output power (if
input power from your possible), or reduce the
autosound system. autosound system's volume.
An output channel has Turn your autosound system
shorted. off then turn it back on.
The amplifier might Turn your autosound system
have shut down. off and let the amplifier
cool. Make sure the
amplifier is properly
ventilated. The amplifier
will turn itself back on
when it cools. Then, turn
your autosound system back
on.

XL-50 Trunk-Mount Stereo Amplifier
(120-2013) Care and Maintenance Faxback Doc. # 40185
Your Optimus XL-50 High-Power Trunk-Mount Stereo Amplifier is an example of
superior design and craftsmanship. The following suggestions will help
you care for your amplifier so you can enjoy it for years.
Keep the amplifier dry. If it gets wet, wipe it dry immediately.
Liquids might contain minerals that can corrode the electronic circuits.
Keep the amplifier away from dust and dirt, which can cause premature
wear of parts.
Handle the amplifier gently and carefully. Dropping it can damage
circuit boards and cases and can cause the amplifier to work improperly.
Wipe the amplifier with a damp cloth occasionally to keep it looking
new. Do not use harsh chemicals, cleaning solvents, or strong
detergents to clean the amplifier.
Modifying or tampering with the amplifier's internal components can cause
a malfunction and might invalidate your amplifier's warranty and void your
FCC authorization to operate it. If your amplifier is not performing as it
should, take it to your local RadioShack store for assistance.
THE FCC WANTS YOU TO KNOW
Your amplifier might cause TV or radio interference even when it is
operating properly. To determine whether your amplifier is causing the
interference, turn off your amplifier. If the interference goes away, your
amplifier is causing it. Try to eliminate the interference by:
Moving your amplifier away from the receiver
Contacting your local RadioShack store for help
REPLACING THE FUSE
If the amplifier does not operate, you might need to replace the red power
cable's 7.5-amp SFE-type fuse or the 7.5-amp blade-type fuse on the
amplifier's back panel. Check both fuses.
Important: Let the amplifier cool down and see if it starts again before
you assume a fuse needs to be replaced.

Caution: Do not use a fuse with ratings other than those specified here.
Doing so might damage your amplifier.
Replacing the SFE-Type Fuse
1. Disconnect the cable from the vehicle's negative (-) battery terminal.
2. Push together and twist the fuse holder's parts on the red power cable
until they spring apart. Then remove the fuse.
3. If the fuse is blown, replace it. Use only an SFE-type fuse with the
proper rating (included with other fuses in Cat. No. 270-1262). The
fuse must be 7.5 amps.
4. Reassemble the fuse holder by inserting the fuse into the longer of the
fuse holder's ends, and pushing together and twisting the two parts
until they latch together.
5. Reconnect the cable to the vehicle's negative (-) battery terminal.
Replacing the Blade-Type Fuse
1. Disconnect the cable from the vehicle's negative (-) battery terminal.
2. Grasp the fuse's plastic end and pull it out.
3. If the fuse is blown, replace it. Use only a blade-type fuse with the
proper rating (supplied with Cat. No. 270-1201). The fuse must be
7.5 amps.
4. Grasp the new fuse's plastic end and push it in.
5. Reconnect the cable to the vehicle's negative (-) battery terminal.

XL-50 Trunk-Mount Stereo Amplifier
(120-2013) Specifications Faxback Doc. # 40186
10% THD Output Power @ 14.4 VDC 1 kHz..............................25 Watts
Frequency Response...................................20-20,000 Hz (+/-3 dB)
Input Impedance..................................................11.5 kOhms
Input Sensitivity (for 10% THD Output Power)
Low Input............................................................150 mV
High Input............................................................2.5 V
Power Supply Voltage................DC 14.4 V Negative Ground (10.5 - 16 V)
Speaker Impedance....................................................4 Ohms
Maximum Current Draw..................................................7.5 A
Dimensions (HWD).................2 x 9 x 6 5/8 Inches (5.2 x 2.3 x 16.9 cm)
Net Weight...............................................2.25 lbs (1.02 kg)
Specifications are typical; individual units might vary. Specifications
are subject to change and improvement without notice.
(km-06/25/1997)
LN-03/04