Kenwood KAC-624 Power Amplifier

Introduction

Thank you for purchasing the Kenwood KAC-624 Power Amplifier. Please read this instruction manual carefully to ensure you obtain the best performance from your new power amplifier. Familiarity with the installation and operation procedures will be beneficial.

For your records, please record the serial number, found on the back of the unit, and keep it in a safe place. Refer to the model and serial numbers whenever you contact your Kenwood dealer for information or service.

Model: KAC-624

Serial number: ____________________

System Examples

This section illustrates how to set up a high-power output system using two KAC-624 units.

System Configuration with Two KAC-624 Units:

Connect the center unit (cassette receiver, graphic equalizer, etc.) to the KAC-624 units using RCA cables. Ensure the left and right outputs from the center unit are connected to the corresponding inputs on the KAC-624. The power control lead from the center unit should be connected to the power control terminal on the KAC-624.

Connections:

• Center Unit to KAC-624: Use RCA cables for audio signals. Connect the left output (white) to the left input (white) and the right output (red) to the right input (red).
• Power Control: Connect the power control lead from the center unit to the power control terminal on the KAC-624.
• Speakers: Connect the left and right speakers to the respective speaker output terminals on the KAC-624.
• Power and Ground: Connect the power lead and ground lead to the corresponding terminals. The ground lead should be connected to a metal part of the car chassis that acts as an electrical ground.

Operation Switch Setting:

The OPERATION switch allows you to select the amplification method of input signals.

• STEREO position: The input left and right signals are amplified separately. Use this position when the unit is used as a stereo amplifier.
• MONO position: The input left signal is amplified twice the normal boost level. Use this position when the unit is used as a high-power monaural amplifier. (The input right signal is not output.)

Installation

Installation Location:

The power amplifier can be installed in a location away from the driver's seat, such as inside the trunk, as it has no parts requiring operation. Ensure the location allows for adequate heat dissipation.

Installation Procedure:

1. Before starting installation, disconnect the negative terminal of the battery to prevent short circuits.
2. Connect the input and output leads.
3. Connect the ground lead to the metal body of the car.
4. Connect the power lead.
5. Install the unit in the car.
6. Connect the negative terminal of the battery.

CAUTION:

• Do not install the unit under the carpet, as heat build-up may occur and damage the unit.
• Install this unit in a location which allows heat to easily dissipate. Once installed, do not place any object on top of the unit.
• After installing the unit, check to make sure that electrical equipment such as brake lamps, turn signal lamps, and windshield wipers operate normally.
• Install the unit securely in a location that does not interfere with driving.

Controls

OPERATION Switch:

This switch selects the amplification method for input signals (STEREO or MONO).

Input Sensitivity Control:

Adjust this control according to the pre-out level of the center unit connected to this unit. Refer to the center unit's instruction manual for its pre-out level.

NOTE:

Refer to "SPECIFICATIONS" in the center unit's instruction manual regarding the pre-out level.

TRI-MODE Configuration

A subwoofer can be added to the system using only coils and capacitors in the stereo 2-channel speaker system.

Operation Switch Setting:

Set the OPERATION switch to STEREO or MONO as required.

Characteristics of Coil and Capacitor:

• Coil (L): Passes low frequencies and blocks high frequencies (Low pass filter).
• Capacitor (C): Passes high frequencies and blocks low frequencies (High pass filter).

6dB/octave for High and Low pass filter:

This section provides a table of recommended coil (L) and capacitor (C) values for different crossover frequencies and speaker impedances (2 ohm and 4 ohm) to create a 6dB/octave high and low pass filter.

Table of content for 6dB/octave:

Note: If coils and capacitors with the exact values listed are not available, similar or close values can be used without affecting performance. Formulas are provided to calculate values for coils and capacitors not listed in the table.

CAUTION: Ensure the combined impedance of your speaker system, as seen from the KAC-624, is at least 2 ohms. An impedance of less than 2 ohms will damage the amplifier.

NOTE: Using the optional TRI-MODE PASSIVE CROSSOVER NETWORK "KPX-T120" simplifies system wiring.

Troubleshooting

This section provides a guide to common issues and their solutions.

Specifications

Specifications are subject to change without notice.

Audio Section

• Max Power Output: Normal: 80 W x 2, Bridged: 180 W x 1
• Rated Power Output (4Ω): Normal (20 Hz-20 kHz, less than 0.08% THD): 40 W x 2, Bridged (1 kHz, 0.8%): 110 W x 1
• Rated Power Output (2Ω): Normal (1 kHz, 0.8% THD): 55 W x 2
• Frequency Response (-3 dB): 4 Hz~45 kHz
• Signal to Noise Ratio: 100 dB
• Sensitivity (MAX.): 0.15 V (rated output)
  (MIN.): 3.0 V (rated output)
• Input Impedance: 10 kΩ
• Damping Factor (100 Hz): More than 100

General

• Operating Voltage: 14.4 V (11-16 V allowable)
• Current Consumption (MAX.): 15 A
• Dimensions (W x H x D): 220 x 48 x 150 mm (8-11/16 x 1-7/8 x 5-7/8 in.)
• Weight: 1.6 kg (3.5 lb)

Safety Precautions

WARNING: To prevent fires and avoid personal injury in case of accidents.

• When extending the Power supply or Ground lead, avoid short circuits by using 3 mm² (AWG12) or larger automotive grade cable.
• Check to be sure that no metal objects (tools, needles, coins) are left inside the unit.
• If you smell or see smoke, disconnect the unit immediately and consult your KENWOOD dealer. Continued use can cause a fire or permanent damage to the unit.
• Do not touch the unit during use because the surface of the unit becomes hot and may cause burns if touched.

CAUTION: To keep the unit in proper working order.

• Be sure it's connected to a 12V DC power supply with a minus ground connection.
• Do not open front panel or top/bottom cover.
• Do not expose this unit to direct sunlight or high heat.
• Keep it clean and dry.
• Be sure it is fastened securely and not exposed to excess vibration.

NOTE: If you have difficulty in installing this unit in your vehicle, please contact your KENWOOD dealer.

Cleaning:

1. Always turn the power OFF before cleaning.
2. Wipe the front panel and other exterior surfaces with a soft dry cloth or a soft cloth lightly moistened with a neutral detergent.

CAUTION: DO NOT use abrasive pads or paint thinner, benzene, or other volatile solvents. These may remove the indicator characters.

FCC WARNING: This equipment generates and uses radio frequency energy. Changes or modifications other than those expressly approved in the instruction manual may cause interference with radio and television reception. Unauthorized changes may lead to the user's loss of the authority to operate this equipment.

Accessories

Part name

Self-tapping screws (4 x 16 mm)

External View

[Screw Icon]

Number of Items

4