Radio Shack Trunk Mount User Manual

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Trunk Mount Amplifier

4-Channel 100-Watt

Cat. No. 12-1976

OWNER’S MANUAL

Please read before using this equipment.

4 × 25 Watt

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FEATURES

Your Optimus 4 Mount Amplifier is designed to produce a total of 100 watts to give added punch and power to your vehicle’s existing stereo system.

The amplifier produces up to 25 watts per channel of clean, powerful sound at all audio frequencies with minimum distortion. And, you can connect line-level as well as speaker outputs to the amplifier.

Its features include:

14k Gold-Plated Noise-Isolated Line-Level Input Jacks

connect low-level (pre-amplifier) signal inputs to match your autosound system’s output for the best high-fidelity performance.

14k Gold-Plated Speaker Termi-

designed for low impedance,

nals

high conductivity, and m inimum corrosion to provide the highest signal transfer and lowest sound distortion.

25 Watt Trunk

let you

Input Level Control

the level (high or low) of the audio signals that enter the amplifier.

Automatic Power Switchin

matically turns on/off the amplifier when you turn on/off your autosound system.

Short Circuit Protection

sound if any output channel shorts to protect the amplifier from damage.

Power Indi cator

is on.

If the connectors from your au-

Note:

tosound system are not compatible with the amplifier’s connectors, your local Radio Shack store sells adapter harnesses for many vehicles.

lets you adjust

- auto -

distorts

lights when power

Opti mus and Radio Shack are registered tr ademarks used by Tandy Corporation.

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CONTENTS

Preparation ..................................................................................................... 4

Choosing a Mounting Location .................................................................. 4

Before You Begin the Installation ............................................................... 4

Connecting Ground and Primary/Switched Pow er .................................... 5

Connecting Your Autosound System ......................................................... 7

Low Level Input Connections ............................ ....... ....... ..... ....... ....... . 7

High-level Input Connections ............................................................ 10

Connecting the Speakers ........................................................................ 13

Preparing the Speaker Wires ............................................................ 13

Connecting Four Speakers ................................................................ 14

Connecting Two Speakers ................................................................ 15

Testing the Connections .......................................................................... 16

Mounting the Amplifier ............................................................................. 16

Operation ...................................................................................................... 18

Turning On the Amplifier .......................................................................... 18

Setting the Level Control ......................................................................... 18

Maintenance .................................................................................................. 20

Replacing the Fuses ................................................................................ 21

Replacing the Tube-Type Fuse ......................................................... 21

Replacing the Blade-Type Fuse ........................................................ 21

Specifications ............................................................................................... 22

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PREPARATION

CHOOSING A MOUNTING LOCATION

The ideal 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 The amplifier gets very hot while it is on. Do not touch the amplifier or

Warnin

place flammable objects near it while it is on.

BEFORE YOU BEGIN THE INSTAL LATION

Before you install your amplifier, carefully read all the instructions in this owner’s manual. You should be able to answer all of these questions about your vehicle’s electrical and sound systems.

• Does my vehicle have a 12-volt negative ground system? (If it does not, you

cannot use this amplifier.)

• Which of the amplifier’s wires is the power wire?

• How do I connect a wire to the fuse box?

• Which amplifier terminals are line-level inputs, which are speaker-level

inputs, and which are speaker outputs?

Important!

• Be aware that installation in your vehi cle may require cutting or modifying

your vehicle.

• Do not cut any of the amplifier’s wires. If you cut any wir e, you cannot obtain

a refund or exchange on this product. Rad io Shack wil l provide warranty service if you cut a wire and find the product is defective.

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Cautions:

• To prevent damage to your amplifier or autosound system, you m ust first connect the ground, primary, and switched power wires (as described in “Connecting Ground and Primary/Switched Power” bef ore you connect the speakers to the amplifier. Make the connections only in the order shown. Damage to the amplifier is possible if you connect any wire incorrectly.

• Turn on the power to test the connections before you permanen tly mount the amplifier (see “Testing the Power Connections”).

• Be sure y our speakers can handle 25 wa tts per channel i f you connect the autosound system to two pairs of speakers (or 50 watts per channel if you connect the autosound system to only one pair of speakers). Each speaker must have an impedance of at least 4 ohms. Your local Radio Shack store carries a full line of speakers to choose from.

CONNECTING GROUND AND PRIMARY/SWITCHED POWER

1. To prevent damage to your amplifier or autosound system while m aking the connections, disconnect the negative (

) cable from your vehicle’s battery.

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Note: After you complete th e connections and reconnect the battery wire, you will need to reset all clock/tim er/memory devices in your vehicle.

2. Connect the supplied dark blue/white wire’s end to the amplifier’s (remote power) terminal.

3. Securely connect the supplied dark blue/white wire’s male quick disconnect plug to your autosound system’s switched power lead.

This connection turns your amplifier on or off when you turn your autosound system on or off.

Note: If your autosound system does not have a remote power output lead, connect this wire to a point in your vehicle’s ignition switch that provides 12volt battery power when the ignition is set to ON or ACC. This connection turns on the amplifier when you turn your i gnition switch to on (or to ACC) and turns off the amplifier when you turn off the ignition.

4. Connect the black wire’s spade connector to the amplifier’s

5. Securely connect the black wire’s eyelet-terminal to a nearby metal ground, such as a bolt attached to a part of the vehicle’s chassis.

Note: Be sure the bolt is n ot insulated from the chas sis by a p lastic part or other insulating material.

6. Connect the red wire’s spade connector to the amplifier’s

7. Remove the nut from t he battery’s positive ( red wire’s 10A fused eyelet terminal over the end of the bolt.

Caution: Due to the amplifier’s high current requirement, you MUST connect the red wire’s fused end directly to the vehicle’s positive ( cable terminal or damage to your vehicle’s wiring could result.

) terminal bolt, the n pl ace t he

GND

+12V

terminal.

REM

termi n al.

) battery

Note: Do not reconnect your vehicle battery’s negative (

) cable yet.

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CONNECTING YOUR AUTOSOUND SYSTEM

Low Level Input Connections

You can connect your autosou nd system’s low-level phono output jacks to the amplifier’s

Note:

and the amplifier, the amplifier’s For the best results, use shielded audio cables, such as Cat. No. 42-2368 (not

supplied). If your autosound system has only two phono out puts, you will also need two shielded Y-adapter cables, such as Cat. No. 42-2435 (not supplied).

1. Temporarily place the am plifier as close as possible to the s elected mount-

LOW INPUT

phono jacks.

For a cleaner, less n oisy signa l t ransfe r between your autosound s ystem

LOW INPUT

phono jacks are gold-plated.

ing location.

If your autosound system has four phono output s and you are using four speakers

as follows: front-left to and rear-right to

, connect the autosound system to the amplifier using audio cables

FRONT L

REAR R

, front-right to

FRONT R

, rear-left to

REAR L

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If your autosound system has four phono outputs but you are using only two speakers (front or rear)

, connect only the corresponding autosound sys-

tem’s output jacks to the amplifier using audio cables as follows:

• front-l e ft to

• rear-left to

FRONT L

REAR L

and front-right to

and rear-right to

FRONT R

REAR R

, or

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