2-1977.fm Page 1 Tuesday, July 13, 1999 10:07 AM Cat. No. 12-1977 OWNER’S MANUAL Please read before using this equipment.
12-1977.fm Page 2 Tuesday, July 13, 1999 10:07 AM FEATURES Your Optimus 85 × 4 High Power 4Channel Trunk Mount Amplifier is designed to produce a total of 340 watts to give added punch and power to your vehicle’s existing stereo system. The amplifier produces up to 85 watts per channel of clean, powerful sound at all audio frequencies with minimum distortion.
12-1977.fm Page 3 Tuesday, July 13, 1999 10:07 AM Mute Turn On Circuit - eliminates the irritating thump noise that some amplifiers produce when you turn them on. Power Indicator - lights when power is on. Full MOSFET Power Supply - produces enough power to supply the main amplifier and has a considerable amount of reserve power for peak “high demand” situations. Short Circuit Protection - distorts sound if any output channel shorts so you can know to turn off the amplifier.
12-1977.fm Page 4 Tuesday, July 13, 1999 10:07 AM CONTENTS Preparation ..................................................................................................... 5 Choosing a Mounting Location .................................................................. 5 Before You Begin the Installation .............................................................. 5 Connecting Ground and Primary/Switched Power .................................... 6 Connecting to Your Autosound System ...................
12-1977.fm Page 5 Tuesday, July 13, 1999 10:07 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.
12-1977.fm Page 6 Tuesday, July 13, 1999 10:07 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.
12-1977.fm Page 7 Tuesday, July 13, 1999 10:07 AM 2. Securely connect the supplied dark blue/white wire’s spade connector end to the amplifier’s REM (remote power) terminal. 3. Connect the dark blue/white wire’s other end to your autosound system’s switched power lead using a twist-on terminal connector (such as Cat. No. 64-3057, not supplied).
12-1977.fm Page 8 Tuesday, July 13, 1999 10:07 AM CONNECTING TO YOUR AUTOSOUND SYSTEM Low Level Input Connections You can connect your autosound system’s low-level phono output jacks to the amplifier’s low-level phono input jacks. For the best results, use shielded audio cables, such as Cat. No. 42-2368 (not supplied). 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. 1.
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12-1977.fm Page 10 Tuesday, July 13, 1999 10:07 AM If your autosound system has only two phono output jacks (left and right) and you are using four speakers, use two Y-adapter audio cables to make the connections as follows: Note: For the best results, use shielded phono plug-to-phono plug Yadapter audio cables, such as Cat. No. 42-2368 (not supplied). • Connect one of the Y-adapter’s double phono plug ends to the amplifier’s CH1 phono jack.
12-1977.fm Page 11 Tuesday, July 13, 1999 10:07 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 CH1 and CH2, or CH3 and CH4, phono jacks. High-Level Input Connections If your autosoiund system has only speaker outputs, you can connect them to the amplifier’s HIGH INPUT CH4 CH3 and HIGH INPUT CH2 CH1 sockets using the floating ground connection or the common ground connection method.
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12-1977.fm Page 14 Tuesday, July 13, 1999 10:07 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 -).
12-1977.fm Page 15 Tuesday, July 13, 1999 10:07 AM Connecting Four Speakers 1. Connect one end of a speaker wire’s marked conductor to the amplifier’s CH1 + terminal (front-left positive). 2. Connect the unmarked conductor’s end to the amplifier’s CH1 (front-left negative). - terminal 3. Repeat Steps 1 and 2 to connect another speaker wire to the amplifier’s CH2 (front-right) terminals. 4. Repeat Steps 1-3 to connect speaker wires to the amplifier’s CH3 (rear-left) and CH4 (rear-right) terminals. 5.
12-1977.fm Page 16 Tuesday, July 13, 1999 10:07 AM Connecting Two Speakers (Unbridged Connection) If you are connecting only two speakers, you can connect them to the amplifier’s front (CH1 and CH2) or rear (CH3 and CH4) speaker terminals. Caution: This is an unbridged connection that produces 85 watts per channel. If you do not have high power speakers, use this connection. 1.
12-1977.fm Page 17 Tuesday, July 13, 1999 10:07 AM Connecting Two Speakers (Bridged Connection) If you are connecting only two speakers (left and right), you can add (bridge) the power output of two channels (front and back) to produce the combined power of both from each of the two speakers. Caution: This is a bridged connection that produces 170 watts per speaker. Use this connection only if you have high quality speakers capable of handling a power output of 170 Watts. 1.
12-1977.fm Page 18 Tuesday, July 13, 1999 10:07 AM Connecting Two Unbridged Speakers and One Unbridged Subwoofer 1. Connect the two speakers to the CH1 and CH2 terminals (front speakers) or to the CH3 and CH4 terminals (rear speakers). 2. For an unbridged connection, connect the subwoofer to the amplifier’s CH3 or CH4 terminals (if you used the front speaker connections in Step 1) or the CH1 or CH2 terminals (if you used the rear speaker connections in Step 1). 3.
12-1977.fm Page 19 Tuesday, July 13, 1999 10:07 AM Connecting Two Unbridged Speakers and One Bridged Subwoofer 1. Connect the two speakers to the CH1 and CH2 terminals (front speakers) or to the CH3 and CH4 terminals (rear speakers). 2. For a bridged connection, connect the subwoofer to the amplifier’s + CH3 and CH4 + terminals (if you used the front speaker connections in Step 1) or the + CH1 and CH2 + terminals (if you used the rear speaker connections in Step 1). 3.
12-1977.fm Page 20 Tuesday, July 13, 1999 10:07 AM TESTING THE CONNECTIONS Before you permanently mount the amplifier, connect 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.
12-1977.fm Page 21 Tuesday, July 13, 1999 10:07 AM MOUNTING THE AMPLIFIER Before you begin mounting the amplifier, make sure you have the following supplied hardware necessary for mounting. • 6 sheet-metal screws • 6 spring washers • 6 flat washers Then confirm that the amplifier fits your vehicle’s mounting area. Caution: Be careful to not drill into anything behind the mounting surface 1. Temporarily disconnect your vehicle battery’s negative (-) cable again. 2.
12-1977.fm Page 22 Tuesday, July 13, 1999 10:07 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.
12-1977.fm Page 23 Tuesday, July 13, 1999 10:07 AM OPERATION TURNING ON THE AMPLIFIER The amplifier automatically turns on whenever you turn your vehicle’s ignition switch to ACC or ON. POWER lights when the amplifier is operating. SETTING THE LEVEL CONTROL For the best performance, you can adjust the level of audio signals that enter the amplifier by following these steps.
12-1977.fm Page 24 Tuesday, July 13, 1999 10:07 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 the left and right LEVEL controls 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.
12-1977.fm Page 25 Tuesday, July 13, 1999 10:07 AM MAINTENANCE Your Optimus 85 × 4 High Power 4-Channel Trunk Mount Amplifier is an example of superior design and craftsmanship. The following suggestions will help you care for your (product name) 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. Handle the amplifier gently and carefully.
12-1977.fm Page 26 Tuesday, July 13, 1999 10:07 AM REPLACING THE FUSES If the amplifier shuts down, you might need to replace the power wire’s 50-amp tube-type fuse, either of the two 25-amp blade-type fuses on the back panel, or all three fuses. Cautions: • Do not use a fuse 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.
12-1977.fm Page 27 Tuesday, July 13, 1999 10:07 AM SPECIFICATIONS 10% THD Output Power @ 14.4 VDC 1 kHz (4 Channel Mode) ........................................................................... 85 W ¥ 4 (Bridged Mode) ........................................................................170 Watts ¥ 2 Frequency Response ........................................................20–20,000 Hz (±3 dB) Input Impedance Low Input ..................................................................................
12-1977.fm Page 28 Tuesday, July 13, 1999 10:07 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.
