User manual SONY XM-5540

[. . . ] The colour of the POWER/PROTECTOR indicator will change from green to red, and the unit will shut down. If this happens, turn off the connected equipment, take out the cassette tape or disc, and determine the cause of the malfunction. If the amplifier has overheated, wait until the unit cools down before use. ** Pulse power supply This unit has a built-in power regulator which converts the power supplied by the DC 12 V car battery into high speed pulses using a semiconductor switch. [. . . ] Choose the mounting location carefully so the unit will not interfere with the normal movements of the driver and it will not be exposed to direct sunlight or hot air from the heater. Do not install the unit under the floor carpet, where the heat dissipation from the unit will be considerably impaired. First, place the unit where you plan to install it, and mark the positions of the four screw holes on the mounting board (not supplied). Then drill a 3 mm pilot hole at each mark and mount the unit onto the board with the supplied mounting screws. The mounting screws are all 15 mm long, so make sure that the mounting board is thicker than 15 mm. If the fuse blows again after replacement, there may be an internal malfunction. When replacing the fuse, be sure to use one matching the amperage stated above the fuse holder. Never use a fuse with an amperage rating exceeding the one supplied with the unit as this could damage the unit. This unit is designed for negative earth 12 V DC operation only. Use speakers with an impedance of 2 to 8 ohms (4 to 8 when used as a bridging amplifier). Do not connect any active speakers (with built-in amplifiers) to the speaker terminals of the unit. If you use small capacity speakers, they may be damaged. Do not connect the # terminal of the speaker system to the car chassis, and do not connect the # terminal of the right speaker with that of the left speaker. Install the input and output cords away from the power supply lead as running them close together can generate some interference noise. Therefore, it may not perform to its full potential if used with the speaker cords supplied with the car. If your car is equipped with a computer system for navigation or some other purpose, do not remove the earth lead from the car battery. If you disconnect the lead, the computer memory may be erased. To avoid short circuits when making connections, disconnect the +12 V power supply lead until all the other leads have been connected. Turn on or off the LPF switch at the unit rear as illustrated below. Note When you tighten the screw, be careful not to apply too much torque* as doing so may damage the screw. * The torque value should be less than 1 N· Pass the leads through the cap, connect the leads, then cover the terminals with the cap. * If you have the factory original or some other car audio without a remote output on the amplifier, connect the remote input terminal (REMOTE) to the accessory power supply. [. . . ] The input level can be adjusted with this control when using source equipment made by other manufacturers. Turn it in the clockwise direction when the output level of the car audio seems low. Connect the +12 V power supply lead only after all the other leads have been connected. Be sure to connect the earth lead of the unit securely to a metal point of the car. [. . . ]