User manual SONY XM-222

[. . . ] â· This power amplifier employs a protection circuit* to protect the transistors and speakers if the amplifier malfunctions. Do not attempt to test the protection circuits by covering the heat sink or connecting improper loads. â· Do not use the unit with a weak battery as its optimum performance depends on a good power supply. [. . . ] â· Dual mode connection can be made for a multi-speaker system. Direct connection can be made with the speaker output of your car audio if it is not equipped with the line output (High level input connection). * 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. These pulses are stepped up by the built-in pulse transformer and separated into both positive and negative power supplies before being converted into direct current again. This is to regulate fluctuating voltage from the car battery. This light weight power supply system provides a highly efficient power supply with a low impedance output. Mount the unit either inside the trunk or under a seat. â· 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. â· 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. Connect the +12 V power supply lead only after all the other leads have been connected. â· Be sure to connect the ground lead of the unit securely to a metal point of the car. A loose connection may cause a malfunction of the amplifier. â· Be sure to connect the remote control lead of the car audio to the remote terminal. â· Use a power supply lead with a fuse attached (15 A). â· Place the fuse in the power supply lead as close as possible to the car battery. [. . . ] In a 12 decibels/octave system where both a choke and capacitor are used in series to form a circuit, great care must be taken when they are connected. In such a circuit, there is going to be an increase in the current which bypasses the speaker with frequencies around the crossover frequency. If audio signals continue to be fed into the crossover frequency area, it may cause the amplifier to become abnormally hot or the fuse to blow. [. . . ]