Nakamichi NHPD600.1
Class-D Mono Block Power Amplifier
User Manual
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Introduction
Thank you for your purchase of this Nakamichi product. We warmly welcome you to the Nakamichi family! Please keep your original invoice and purchase receipt in a safe place for future service and warranty claims. You may also contact your appointed Nakamichi service agent for any future technical support requirements.
Accessory List
| Item | Quantity |
|---|---|
| User Manual | 1pc |
| Amplifier | 1pc |
| Mounting Screw ($4x15mm) | 4pc |
| Remote control | 1pc |
| Wrench | 2pc |
| Remote Mounting Screw($3x12mm) | 2pc |
Specifications
| Parameter | Value |
|---|---|
| N-power Output@4Ω | 260W X 1 |
| N-power Output@2Ω | 450W X 1 |
| N-power Output@1Ω | 600W X 1 |
| Max power | 4200W |
| T.H.D (Total Harmonic Distortion) | ≤0.2% |
| Frequency Response | 20Hz-20kHz |
| Signal To Noise Ratio | ≥102dB |
| Sensitivity | 0.2~6V |
| Unit Dimensions (LxHxW) | 150mm x 108mm x 51mm |
| Net Weight | Approx. 1.18kg |
| Box Dimensions (LxHxW) | 227mm x 178mm x 80mm |
| Gross Weight | Approx. 1.44kg |
All specifications subject to change without notice.
Panel Controls and Features
The amplifier features several controls and connection terminals:
Diagram Description: The amplifier has a rectangular chassis with connection terminals and control knobs on the top and rear panels. The top panel displays controls like LINE INPUT, GAIN, SUB BASS, SONIC BOOST, LPF, REMOTE, SPEAKER OUTPUT, +12V, REM, and GND.
Control Descriptions:
- A. LOW LEVEL RCA INPUT: These RCA input jacks connect to your source unit's RCA low-level outputs. For high-level outputs, an optional adapter can be used. High-quality twisted pair car audio cables are recommended to reduce the possibility of audio signal degradation.
- B. SPEAKER GAIN CONTROL: This control matches the amplifier's sensitivity to the source signal voltage.
- C. INFRASOUND CROSSOVER FREQUENCY RANGE: The infrasound crossover frequency range is controlled between 10Hz and 50Hz.
- D. BASS BOOST: This feature increases the sound level in the bass frequencies.
- E. SPEAKER LOW PASS CROSSOVER FREQUENCY: Adjustable low pass frequency range from 50Hz to 20kHz.
- F. REMOTE PORT: This port can be connected to adjust the sound level of the amplifier within a five-meter range.
- G. SPEAKER CONNECTIONS: Terminals for connecting your speakers, woofers, or full-range speakers. Ensure proper polarity during connection. Never connect speaker cables to the chassis ground.
- H. POWER AND PROTECTION INDICATOR: A red LED lights up if there is a fault present in the amplifier. Please disconnect the amplifier and resolve the fault before reconnecting. A blue LED lights up when the amplifier is operating normally.
- I. +12V = POWER SUPPLY: Connect this terminal through a fuse or circuit breaker to the positive terminal of the vehicle battery or the positive terminal of an isolated audio system battery.
- J. REM(ON/OFF) CONTROL LINE: When using low-level inputs, the amplifier's REM-IN should be connected to the REM-OUT of the source unit. The source unit will control the amplifier to automatically turn on or off.
- K. GND(-) = GROUND CONNECTION: Connect this cable directly to the metal frame of the vehicle, ensuring that the metal frame has been stripped of all paint down to the bare metal. Use the shortest distance possible. It is always a good idea to connect to the vehicle battery ground terminal or any other ground points.
Power Connection Leads
Diagram Description: A diagram illustrates the power connections. It shows the vehicle battery, a fuse, and connections to the amplifier's +12V, REM, and GND terminals.
Notes on the power supply: Connect the +12V power input lead only after all other leads have been connected. Be sure to connect the ground wire of the unit securely to a metal part of the car. A loose connection may cause a malfunction of the amplifier.
Control line: The unit is turned on by applying +12V volts to this terminal. This terminal does not draw heavy current like the two power terminals, so a thinner connecting wire is acceptable. Standard 18 GAUGE is fine and the standard color is blue.
Speaker Connection Leads
Use the power supply lead with a fuse attached whose value is the same as the original fuse. Place the fuse in the power supply lead as close as possible to the car battery. During full power operation, maximum current will run through the system. Therefore, make sure that the leads to be connected to the +12V and GND terminals of the unit respectively must be larger than 8-Gauge (AWG.8).
Diagram Description: Diagrams show speaker connection leads for 1-Channel Mode, illustrating how to connect speakers to the output terminals.
Troubleshooting
If you experience operation or performance problems, compare your installation with the wiring diagram. If problems persist, consult the following tips:
| Symptom | Possible Cause | Action to Take |
|---|---|---|
| NO OUTPUT | Low or no remote turn-on input | Check remote turn-on voltage output at amplifier and correct as needed. |
| Fuse blown | Check power wire integrity and reversed polarity, repair as needed and replace fuse. | |
| Power wires not connected | Check power wire and ground connections and repair or replace as needed. | |
| AUDIO CYCLES ON AND OFF | Audio input not connected or no output from source | Check input connections and signal integrity, repair or replace as needed. |
| Speaker wires not connected | Check speaker wires and repair or replace as needed. | |
| Speaker are blown | Check system with known working speaker and repair or replace speaker as needed. | |
| DISTORTED OUTPUT | Thermal protection engages when amplifier heat sink temperature exceeds 90°C | Ensure proper ventilation for amplifier and improve ventilation as needed. |
| Loose or poor audio input | Check input connections and repair or replace as needed. | |
| Amplifier level sensitivity set too high; exceeding maximum output capability of amplifier | Reset gain referring to the tuning section of the manual for detailed instructions. | |
| DISTORTED OUTPUT (CONT'D) | Impedance load to amplifier too low | Check speaker impedance load, if below 2Ω stereo or 1Ω mono, rewire speakers to achieve a higher impedance. |
| Shorted speaker wires | Check speaker wire connections and repair or replace as needed. | |
| Speaker not connected to amplifier properly | Check speaker wiring and repair or replace as needed. Refer to the installation section of this manual for detailed instructions. | |
| POOR BASS RESPONSE | Internal crossover not set properly for speaker | Reset crossovers referring to the multi-cross crossover configuration section of this manual. |
| Speaker are blown | Check system with known working speaker and repair or replace as needed. | |
| Speaker wired wrong polarity causing cancellation at low frequencies | Check speaker polarity and repair as needed. Reset crossovers referring to the multi-cross crossover configuration section of this manual for detailed instructions. | |
| Crossover set incorrectly | Check speaker impedance load, if below 2Ω stereo or 1Ω mono, rewire speakers to achieve a higher impedance. | |
| DISTORTED OUTPUT (CONT'D) | Short in power wire or incorrect power connections | Check power and ground connections and repair as needed. |
| Fuse used is smaller than recommended | Replace with proper fuse size. | |
| Too much current being drawn | Check speaker impedance load, if below 2Ω stereo or 1Ω mono, rewire speakers to achieve a higher impedance. | |
| Short in power wire of incorrect | Check power and ground connections and repair as needed. |
Interference
All cables can create interference. The power cable and RCA audio cables are very prone to interference from other sources, while remote cables are less prone. Interference is often caused by the generator, ignition, or any other electronic parts or systems. Most of these problems can be eliminated by correct and careful wiring during setup. Here are some guidelines to follow:
- Use only a shielded audio cable for the wiring between the low-level input of the amplifier and the RCA output of the radio.
- Lay the signal, speaker, and power cables separately with enough distance from one another and also from other car cables. If not possible, you can lay the circuit and ground cable together with the serial cables. Audio and speaker cables should be as far away from these as possible. The REM cable to the automatic antenna output of the radio can be laid together with the signal cables.
- Avoid ground loops by laying the ground wiring of all components towards a central point in a star layout. You can locate the best point by measuring the voltage directly at the battery, and comparing the voltage value with the chosen ground point and the positive terminal of the amplifier. If the measured voltage is only slightly different, you've found the correct central location. Otherwise, please look for another point. You should measure with the ignition point for earth switched on.
- If there are pickups from external electrical sources into the speaker cables, divide the core leads and twist them together.
- If there are noises from the car electrics, add an interference suppression choke into the power wiring.
- If there are humming noises, use thicker ground cables or add further ground cables to the chassis.
- To reduce contact resistance and bad and loose contacts, please solder the cable ends or use multi-core cable ends, spade terminals, or others. Gold-plated spade terminals are free of corrosion and have the lowest contact resistance.
- Should all these measures not bring about any success, the use of a ground loop isolator may solve the problem.
Dimensions
Diagram Description: The amplifier's physical dimensions are approximately 150mm (Length) x 108mm (Width/Height) x 51mm (Depth/Height).
