Kenwood KAC 859 Manual

The Kenwood KAC 859 is a high-performance car amplifier featuring MOSFET power supply, variable low-pass filter, bass boost, speaker level inputs, and thermal/overload/short circuit protection. This 2-channel amplifier delivers 85W RMS per channel at 4 ohms and is designed for superior car audio performance. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

1. Features at a Glance 2. Installation 3. First-Time Setup 4. Specifications 5. Controls and Settings 6. Connecting Devices 7. Operation Guide 8. Protection Features 9. Care & Maintenance 10. Regulatory Information 11. Troubleshooting

Features at a Glance

Key components: MOSFET power supply, variable low-pass filter, bass boost control, speaker level inputs, protection circuits.

Feature	Description
MOSFET power supply	For efficient power conversion and reliability
Variable low-pass filter	Adjustable from 50Hz to 200Hz
Bass boost	+12dB at 50Hz
Speaker level inputs	For connection to factory head units
Protection circuits	Thermal, overload, and short circuit protection
Power terminals	For +12V, ground, and remote connections
Input level control	Adjustable gain control
Bridge mode	For mono operation with increased power
LED power indicator	Shows amplifier status
Cooling fan	For thermal management

Installation

Choose proper mounting location and prepare wiring.

Select mounting location: Choose well-ventilated area away from moisture.
Run power cable: Connect +12V to battery with fuse, ground to chassis.
Connect remote wire: Connect to head unit remote turn-on lead.
Connect audio inputs: Use RCA cables or speaker level inputs.
Connect speakers: Ensure proper impedance matching.

WARNING! Disconnect battery before installation. Use proper gauge wiring for power connections.

First-Time Setup

Configure amplifier settings after installation.

Set input level: Adjust gain control for proper input matching.
Configure crossover: Set low-pass filter frequency as needed.
Adjust bass boost: Set to desired level (if used).
Test operation: Verify all channels working properly.
Fine-tune settings: Make final adjustments for optimal sound.

CAUTION! Set gain properly to avoid distortion and speaker damage.

Specifications

RMS Power: 85W x 2 at 4 ohms
Max Power: 170W x 2 at 4 ohms
Bridged Power: 340W x 1 at 4 ohms
Frequency Response: 10Hz - 50kHz
Signal-to-Noise Ratio: >100dB
Input Sensitivity: 0.2V - 4V
Crossover: Low-pass 50-200Hz, 12dB/octave
Bass Boost: 0 to +12dB at 50Hz
Power Requirement: 14.4V DC
Fuse Rating: 25A x 2

Controls and Settings

Front panel controls: Power indicator, protection indicator.

Adjustment Controls: Input level (gain), low-pass filter frequency, bass boost level, input mode switch (RCA/speaker level).

Input Level: Adjust to match head unit output. Low-pass Filter: Set cutoff frequency for subwoofers. Bass Boost: Increase low-frequency output. Input Mode: Select between RCA and high-level inputs. Bridge Mode: Connect for mono operation.

Connecting Devices

Power: +12V, ground, remote turn-on. Audio: RCA inputs or speaker level inputs. Speakers: 2-channel or bridged mono.

Disconnect battery before making connections.
Connect power wires: +12V (fused), ground, remote.
Connect audio inputs: RCA cables from head unit.
Connect speakers: Observe polarity and impedance.
Reconnect battery and test system.

Tip: Use quality connectors and secure all connections properly.

Operation Guide

Normal stereo operation and bridge mode configuration.

Power on: Amplifier turns on with head unit.
Stereo mode: Left and right channels operate independently.
Bridge mode: Connect speakers between left + and right + terminals.
Adjust settings: Fine-tune for your listening preference.
Monitor operation: Check for proper cooling and performance.

WARNING! Do not operate with impedance below specified minimums.

Protection Features

Thermal Protection: Automatically shuts down if temperature exceeds safe limits. Overload Protection: Protects against excessive current draw. Short Circuit Protection: Prevents damage from speaker wire shorts. DC Offset Protection: Guards against DC voltage at outputs.

Care & Maintenance

Keep amplifier clean and well-ventilated. Check connections periodically for corrosion or looseness.

CAUTION! Do not block ventilation openings. Keep away from moisture and extreme temperatures.

Regulatory Information

FCC Part 15: Class B digital device; complies with interference limits. CE certified for European markets. Copyright © 2025 Kenwood Corporation; all rights reserved. For technical support, visit www.kenwood.com or contact 1-800-536-9663.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No power	Wiring/fuse	Check power, ground, remote connections; verify fuses.
Protection mode active	Overload/short	Check speaker wiring; allow cooling if thermal.
No sound	Input/connections	Verify input connections; check head unit settings.
Distorted sound	Gain settings	Adjust input level; check source material.
Amplifier overheats	Ventilation/load	Improve ventilation; check impedance load.

Reset: Disconnect power for 30 seconds to reset protection circuits.

Service: 1-800-536-9663; www.kenwood.com