2-1976.fm Page 1 Tuesday, July 13, 1999 10:01 AM Cat. No. 12-1976 OWNER’S MANUAL Please read before using this equipment.
12-1976.fm Page 2 Tuesday, July 13, 1999 10:01 AM FEATURES Your Optimus 4 × 25 Watt Trunk 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.
12-1976.fm Page 3 Tuesday, July 13, 1999 10:01 AM CONTENTS Preparation ..................................................................................................... 4 Choosing a Mounting Location .................................................................. 4 Before You Begin the Installation ............................................................... 4 Connecting Ground and Primary/Switched Power .................................... 5 Connecting Your Autosound System .....................
12-1976.fm Page 4 Tuesday, July 13, 1999 10:01 AM 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 Warning: The amplifier gets very hot while it is on.
12-1976.fm Page 5 Tuesday, July 13, 1999 10:01 AM Cautions: • To prevent damage to your amplifier or autosound system, you must first connect the ground, primary, and switched power wires (as described in “Connecting Ground and Primary/Switched Power” before 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.
12-1976.fm Page 6 Tuesday, July 13, 1999 10:01 AM Note: After you complete the connections and reconnect the battery wire, you will need to reset all clock/timer/memory devices in your vehicle. 2. Connect the supplied dark blue/white wire’s end to the amplifier’s REM (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.
12-1976.fm Page 7 Tuesday, July 13, 1999 10:01 AM CONNECTING YOUR AUTOSOUND SYSTEM Low Level Input Connections You can connect your autosound system’s low-level phono output jacks to the amplifier’s LOW INPUT phono jacks. Note: For a cleaner, less noisy signal transfer between your autosound system and the amplifier, the amplifier’s LOW INPUT phono jacks are gold-plated. For the best results, use shielded audio cables, such as Cat. No. 42-2368 (not supplied).
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12-1976.fm Page 9 Tuesday, July 13, 1999 10:01 AM If your autosound system has only two phono output jacks (left and right) and you are using four speakers, first connect the single phono plug end of a Y-adapter shielded audio cable to each autosound system output jack.
12-1976.fm Page 10 Tuesday, July 13, 1999 10:01 AM If your autosound system has only two phono output jacks (left and right) and you are using only two speakers, simply connect them to the amplifier’s corresponding FRONT L and FRONT R, or REAR L and REAR R phono jacks. High-Level Input Connections If your stereo system has only speaker outputs, you can connect them to the amplifier’s rear HIGH INPUT and front HIGH INPUT sockets using the floating ground connection or the common ground connection method.
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12-1976.fm Page 13 Tuesday, July 13, 1999 10:01 AM CONNECTING THE SPEAKERS With the speakers placed in their approximate locations, run one speaker wire from each speaker to the amplifier. We recommend you use 16- or 18-gauge marked or color-coded wires to help you correctly connect the speakers to your amplifier. For the maximum bass response and the best overall performance, keep your speakers properly phased (connect + to + and - to -).
12-1976.fm Page 14 Tuesday, July 13, 1999 10:01 AM Connecting Four Speakers 1. Connect one end of a speaker wire’s marked conductor to the amplifier’s FL+ (front-left positive) terminal. 2. Connect one end of the speaker wire’s unmarked conductor to the amplifier’s FL- (front-left negative) terminal. 3. Repeat Steps 1 and 2 to connect a speaker wire to the amplifier’s FR (frontright) terminals. 4. Repeat Steps 1 - 3 to connect speaker wires to the amplifier’s RL (rear-left) and RR (rear-right) terminals.
12-1976.fm Page 15 Tuesday, July 13, 1999 10:01 AM Connecting Two Speakers If you are connecting only two speakers, you can connect them to the amplifier’s front (FL and FR) or rear (RL and RR) speaker terminals. 1. Connect one end of a speaker wire’s marked conductor to the amplifier’s FL+ (front-left positive) or RL + (rear-left positive) terminal. 2. Connect the end of the speaker wire’s unmarked conductor to the amplifier’s FL− (front-left negative) or RL − (rear-left negative) terminal. 3.
12-1976.fm Page 16 Tuesday, July 13, 1999 10:01 AM TESTING THE CONNECTIONS Before you permanently mount the amplifier, temporarily reconnect your vehicle battery’s negative (-) cable, turn your vehicle’s ignition to ON or ACC, then test the connections. The amplifier is properly connected to the autosound system and speakers if you can verify that the amplifier and the autosound system turn on properly and the speakers’ sound is clear and unmuffled.
12-1976.fm Page 17 Tuesday, July 13, 1999 10:01 AM 3. Using the mounting holes on the amplifier as a guide, mark the locations for the mounting holes. 4. Drill 9/64-inch holes in the marked locations, being careful not to damage anything behind the mounting surface. 5. Attach the amplifier to the mounting surface using the supplied sheet-metal screws and washers. 6. Reconnect the wiring. 7. Reconnect your vehicle battery’s negative (-) cable.
12-1976.fm Page 18 Tuesday, July 13, 1999 10:01 AM OPERATION TURNING ON THE AMPLIFIER The amplifier automatically turns on whenever you turn on your autosound system. POWER lights when the amplifier is operating. SETTING THE LEVEL CONTROL For the best performance, you can adjust the level of the audio signals that enter the amplifier by following these steps. Cautions: • The sound distorts if any output channel shorts. Turn off the amplifier and try to locate the short.
12-1976.fm Page 19 Tuesday, July 13, 1999 10:01 AM 2. Temporarily turn up the autosound system’s volume control to about onethird of its full range. Caution: Never turn the level controls up any farther than you need to get clear sound at two thirds volume maximum. 3. Turn either the left or right LEVEL control clockwise until you can hear the sound at a comfortable level. 4. Turn up the volume on your autosound system until the sound begins to distort.
12-1976.fm Page 20 Tuesday, July 13, 1999 10:01 AM MAINTENANCE Your Optimus 4 × 25 Watt Trunk Mount 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 can contain minerals that corrode electronic circuits. Use and store the amplifier only in normal temperature environments.
12-1976.fm Page 21 Tuesday, July 13, 1999 10:01 AM REPLACING THE FUSES If the amplifier shuts down, you might need to replace the power wire’s 10-amp tube-type fuse (such as Cat. No. 270-1072, not supplied), the 10-amp blade-type fuse (such as Cat. No. 270-1081, not supplied) on the back panel, or both fuses. Cautions: • Do not use fuses with ratings other than those specified here. Doing so might damage your amplifier. • After replacing a fuse, let the amplifier cool down before you turn it on again.
12-1976.fm Page 22 Tuesday, July 13, 1999 10:01 AM SPECIFICATIONS Output Power @ 14.4 VDC 1 kHz 10% THD Front .................................................................................................25W Rear ..................................................................................................25W ¥2 ¥2 Frequency Response ........................................................ 20–20,000 Hz (±3 dB) Input Impedance Low Input ..............................................................
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12-1976.fm Page 24 Tuesday, July 13, 1999 10:01 AM RADIO SHACK LIMITED WARRANTY This product is warranted against defects for 1 year from date of purchase from Radio Shack company-owned stores and authorized Radio Shack franchisees and dealers. Within this period, we will repair it without charge for parts and labor. Simply bring your Radio Shack sales slip as proof of purchase date to any Radio Shack store. Warranty does not cover transportation costs.
