Kenwood KA 405 Manual

The Kenwood KA 405 is a high-fidelity stereo integrated amplifier featuring 45 watts per channel RMS, phono input for turntables, multiple audio inputs, tone controls, loudness contour, speaker selector, and headphone output. Designed for audiophile-grade performance with low distortion and wide frequency response. Below are key sections for safety, features, installation, setup, operation, and troubleshooting.

Features at a Glance

Key components: High-power amplifier section, phono preamp, multiple input selector, tone control circuit, speaker selector, headphone output.

Feature	Description
Power Output	45 watts per channel RMS into 8 ohms
Phono Input	MM cartridge compatible with RIAA equalization
Input Selector	Phono, Tuner, Aux, Tape 1, Tape 2
Tone Controls	Bass and treble adjustment ±10dB
Loudness Contour	Compensates for low volume listening
Speaker Selector	A/B speaker switching
Headphone Jack	Standard 6.35mm (1/4") stereo jack
Power Switch	Main power on/off with indicator light
Volume Control	Logarithmic potentiometer for smooth adjustment
Balance Control	Left/right channel balance adjustment

Installation

Unpack and inspect contents. Place on stable, well-ventilated surface.

1. Connect speakers: Use speaker wire to connect to A/B speaker terminals.
2. Connect audio sources: Phono for turntable, Tuner for radio, Aux for CD player, Tape for recorders.
3. Connect power cord: Plug into standard AC outlet.
4. Ensure proper ventilation: Leave minimum 10cm clearance around amplifier.

WARNING! Ensure proper speaker impedance matching. Do not short-circuit speaker terminals.

First-Time Setup

Power on amplifier; set initial controls to neutral positions.

1. Set volume to minimum: Turn volume knob fully counterclockwise.
2. Set tone controls: Center position for flat response.
3. Select input: Choose appropriate source (Phono, Tuner, Aux, etc.).
4. Adjust balance: Center position for equal left/right output.
5. Test speakers: Gradually increase volume to comfortable level.

CAUTION! Always power off when connecting/disconnecting cables.

Specifications

• Power Output: 45W + 45W RMS at 8 ohms
• Total Harmonic Distortion: 0.08% at rated output
• Frequency Response: 20Hz - 20kHz ±1dB
• Input Sensitivity: Phono: 2.5mV, Aux/Tuner: 150mV
• Signal-to-Noise Ratio: Phono: 76dB, Aux: 90dB
• Tone Control Range: Bass/Treble ±10dB at 100Hz/10kHz
• Power Requirements: 120V/230V AC, 50/60Hz
• Dimensions: 430mm width × 130mm height × 300mm depth
• Weight: 7.5kg

Controls and Settings

Front panel controls: Power switch, Input selector, Volume, Balance, Bass, Treble, Loudness, Speaker selector.

Input Selector: Phono, Tuner, Aux, Tape 1, Tape 2. Tone Controls: Bass and Treble with center detent. Loudness: Engages bass/treble boost at low volumes. Speaker Selector: A, B, A+B, or Off.

Rear panel: Phono input (RCA), Line inputs (RCA), Speaker terminals, AC power inlet.

Connecting Devices

Phono: Connect turntable ground wire and RCA cables. Line inputs: Use RCA cables for CD players, tuners, tape decks.

1. Turn off amplifier before connecting devices.
2. Match left/right channels (white/red RCA connectors).
3. Connect turntable ground wire to ground terminal.
4. Use proper speaker wire gauge for your setup.

Tip: Keep signal cables away from power cords to minimize hum.

Phono Input Setup

Designed for moving magnet (MM) phono cartridges.

1. Connect turntable: RCA cables to Phono input, ground wire to ground terminal.
2. Set input selector to Phono position.
3. Adjust volume gradually from minimum.
4. For moving coil cartridges: Use external step-up transformer.

WARNING! Do not connect line-level sources to phono input - may cause damage.

Tone Controls

Bass and treble controls with center detent for flat response.

• Bass Control: ±10dB at 100Hz
• Treble Control: ±10dB at 10kHz
• Loudness: Engages frequency compensation for low-level listening
• Flat Response: Set both controls to center detent position

Care & Maintenance

Unplug before cleaning. Use soft, dry cloth for exterior. Clean controls with contact cleaner if noisy.

CAUTION! Do not use solvents or abrasive cleaners. Ensure adequate ventilation during operation.

Regulatory Information

Complies with applicable safety standards. Manufactured to Kenwood quality specifications. For service or technical support, contact authorized Kenwood service centers. Copyright © by Kenwood Corporation.

Troubleshooting

Symptom	Possible Cause	Corrective Action
No sound from speakers	Input selection/volume	Check input selector; ensure volume up; verify speaker connections.
Hum or buzz	Grounding/cables	Check turntable ground; separate signal/power cables; verify RCA connections.
Distorted sound	Overload/speakers	Reduce volume; check speaker impedance; verify source signal level.
One channel silent	Balance/connections	Check balance control; verify RCA and speaker connections for both channels.
No phono sound	Ground wire/input	Ensure turntable ground connected; verify phono input selected.

Service: Contact authorized Kenwood service center for internal repairs.