Tuesday, November 24, 2015




# Before making any connections, disconnect the ground terminal of the car battery to avoid short circuits.
# Be sure to use speakers with an adequate power rating. 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 wire as running them close together can generate some interference noise.
# This unit is a high powered amplifier. 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 to remove the ground wire from the car battery. If you disconnect the wire, the computer memory may be erased. To avoid short circuits when making connections, disconnect the +12 V power supply wire until all the other wires have been connected.
Notes on the power supply
# Connect the +12 V power supply wire only after all the other wires have been connected.
# Be sure to connect the ground wire of the unit securely to a metal point of the car. A loose connection may cause a malfunction of the amplifier.
# Be sure to connect the remote control wire of the car audio to the remote terminal.
# When using a car audio without a remote output on the amplifier, connect the remote input terminal (REMOTE) to the accessorypower supply.
# Use the power supply wire with a fuse attached (80 A).
# All power wires connected to the positive battery post should be fused within 456 mm (18 in) of the battery post, and before they pass through any metal.
# Make sure that the vehicle’s battery wires connected to the vehicle (ground to chassis) are of a wire gauge at least equal to that of the main power wire connected from the battery to the amplifier.
# Make sure that the wires to be connected to the +12 V and GND terminals of this unit are at least 4-Gauge (AWG-4) or have a sectional area of more than 22.0 mm2 (7/8 in.2).
# When using passive crossover networks in a multispeaker system, care must be taken as the speaker system’s impedance should not be lower than that of the suitable impedance for this unit.
3 When you are installing a 12 decibels/octave system in your car, the following points must be considered. In a 12 decibels/octave system where both a choke and capacitor are used in series to form a circuit, a great care must be taken when they are connected. In such a circuit, there is going to be an increase in the current which by-passes the speaker with frequencies at around the crossover frequency. If audio signals are continued to be fed into the crossover frequency area, it may cause the amplifier to become abnormally hot or the fuse will be blown. Also if the speaker is disconnected, a series-resonant circuit will be formed by the choke
and the capacitor. In this case, the impedance in the resonance area will decrease dramatically resulting in a short circuit like situation causing a damage to the amplifier. Therefore, make sure that a speaker is connected to such a circuit at all times.
2-way System
Use the THROUGH OUT terminal when you install more amplifiers. The signals are output as they were input. (LOW BOOST, LPF do not work.)
# A maximum 3 amplifiers can be connected to the THROUGH OUT terminal. If you connect more than three amplifiers, it may cause problems such as sound dropout.
# High level input connection cannot use THROUGH OUT.
Bias Adjustment
Note : In Bias Adjustment, adjust RV103 if any of Q108 through
Q113 are replaced. Adjust RV203 if any of Q208 through
Q213 are replaced.
Condition : This adjustment should be performed about one minute
after the remote mode is turned on at a room temperature of about 25°C.

Procedure :
1. Turn the variable resistors RV103 (L-CH) and RV203 (R-CH) full clockwise as seen from the component side to minimize the bias current.
2. The input signal is to be no signal.
3. Apply the voltage to the B+ and REM terminals from the stabilized power supply and gradually increase it up to 12.0 V while checking for any unusual current.
4. Adjust each of RV103 (L-CH) and RV203 (R-CH) so that the power current of the stabilized power supply is increased in steps of 700 mA (total of 1.4 A).
5. After adjustment, check that the power current is at 1.65 to 2.05 A.