O-NOORUS D4 HDMI ARC Stereo Amplifier User Manual

1. Introduction

This manual provides detailed instructions for the setup, operation, maintenance, and troubleshooting of your O-NOORUS D4 HDMI ARC Stereo Amplifier. Please read this manual thoroughly before using the product to ensure proper function and safety.

2. Important Safety Instructions

• Read these instructions.
• Keep these instructions.
• Heed all warnings.
• Follow all instructions.
• Do not use this apparatus near water.
• Clean only with a dry cloth.
• Do not block any ventilation openings. Install in accordance with the manufacturer's instructions.
• Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
• Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
• Only use attachments/accessories specified by the manufacturer.
• Unplug this apparatus during lightning storms or when unused for long periods of time.
• Refer all servicing to qualified service personnel. Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.

3. Package Contents

Verify that all items are present in the package:

• O-NOORUS D4 Power Amplifier
• 48V/5A GaN Adapter
• Bluetooth Antenna
• USB Data Cable
• AC Cord
• User Manual (this document)

4. Product Overview

4.1 Key Features

• TPA3255 PFFB Amplifier: Utilizes a post-filter feedback (PFFB) design for reduced output noise, improved THD+N performance, and better IMD performance. Delivers up to 300W×2 output for clear audio.
• Multi-Inputs and 2.1 Channels: Features HDMI ARC (with TV volume synchronization), Bluetooth 5.3, optical, coaxial, USB, RCA inputs, and a subwoofer output with an 80Hz crossover. Ideal for 2.1 channel audio systems, connecting to TVs, streaming devices, and active subwoofers.
• Customizable Sound: Incorporates NJW1119A 3-band tone control with ±12dB adjustable bass, mid, and treble. Optimize voice clarity and audio balance. A BYPASS mode is available to restore original sound reproduction.
• Upgradeable Op-Amp Design: IC socket design allows for swapping the original OPA1642 op-amp with compatible alternatives like OPA1656, LME49720HA, or MUSES02 for personalized sound customization.

4.2 Front Panel Layout

• Input Selector: Cycles through available audio inputs (HDMI ARC, Bluetooth, Optical, Coaxial, USB, RCA).
• Tone Control Knobs: Adjust Bass, Mid, and Treble levels.
• Tone/Bypass Switch: Engages or bypasses the tone control circuit.
• Volume/Selector Knob: Controls overall volume and can be pressed to select inputs.

4.3 Rear Panel Connections

• HDMI ARC Input: Connects to a TV's HDMI ARC port for audio return channel functionality.
• USB Input: Connects to a computer for digital audio playback.
• Coaxial Input: Digital audio input.
• RCA (L/R) Inputs: Analog audio inputs for devices like CD players or turntables.
• Optical Input: Digital audio input.
• Subwoofer Output: Connects to an active subwoofer.
• Speaker Terminals: Connects to passive speakers (Left and Right).
• Power Input: Connects to the 48V/5A GaN power adapter.
• Bluetooth Antenna Port: Connects the included Bluetooth antenna.

5. Setup Instructions

5.1 Connecting Speakers

1. Ensure the amplifier is powered off and unplugged.
2. Connect your passive speakers to the speaker terminals on the rear panel. Ensure correct polarity (+ to + and - to -) for both left and right channels.
3. Use appropriate gauge speaker wire for optimal performance.

5.2 Connecting Audio Sources

Choose one or more of the following connection methods:

• HDMI ARC: Connect an HDMI cable from your TV's HDMI ARC port to the HDMI ARC input on the amplifier. This allows TV audio to play through the amplifier and enables TV remote volume control.

  

• Bluetooth 5.3: Attach the Bluetooth antenna to the rear panel. Power on the amplifier and select Bluetooth input. On your mobile device, search for "O-NOORUS D4" and pair.

  

• Optical/Coaxial: Connect a digital audio cable from your source (e.g., CD player, game console) to the corresponding input on the amplifier.
• USB: Connect the USB data cable from your computer to the USB input on the amplifier. Your computer should recognize the amplifier as an audio output device.
• RCA: Connect RCA cables from an analog audio source (e.g., turntable, CD player) to the RCA L/R inputs.

  

• Subwoofer Output: If using an active subwoofer, connect it to the Subwoofer Output port.

5.3 Power Connection

1. Connect the 48V/5A GaN adapter to the Power Input port on the amplifier.
2. Plug the AC cord into the power adapter, then into a wall outlet.

6. Operating Instructions

6.1 Power On/Off

Press the power button (usually integrated with the volume knob) to turn the amplifier on or off.

6.2 Input Selection

Rotate or press the Input Selector/Volume knob to cycle through the available audio inputs (HDMI ARC, Bluetooth, Optical, Coaxial, USB, RCA) until your desired source is selected.

6.3 Volume Control

Rotate the Volume knob clockwise to increase volume and counter-clockwise to decrease volume. If using HDMI ARC, the TV remote may also control the amplifier's volume.

6.4 Tone Control

• Bass, Mid, Treble Knobs: Adjust these knobs to fine-tune the audio frequency response to your preference. Each band offers ±12dB adjustment.
• Tone/Bypass Switch: Flip this switch to "BYPASS" to disable the tone controls and listen to the audio in its original, unaltered state. Switch to "TONE" to enable the tone controls.

6.5 Op-Amp Replacement (Advanced Users)

The D4 amplifier features an IC socket design, allowing advanced users to replace the default OPA1642 op-amp with other compatible models (e.g., OPA1656, LME49720HA, MUSES02) for customized sound characteristics. This procedure should only be performed by individuals familiar with electronics and proper handling of sensitive components. Incorrect installation can damage the device.

7. Maintenance

• Cleaning: Use a soft, dry cloth to clean the exterior of the amplifier. Do not use liquid cleaners or solvents.
• Ventilation: Ensure that the ventilation openings are not blocked to prevent overheating.
• Storage: If storing the amplifier for an extended period, unplug it from the power outlet and store it in a cool, dry place.

8. Troubleshooting

9. Specifications

9.1 Output Power Table

10. Warranty Information

O-NOORUS products are designed and manufactured to the highest quality standards. For specific warranty terms and conditions, please refer to the warranty card included with your product or contact O-NOORUS customer support. Keep your purchase receipt as proof of purchase.

11. Customer Support

If you encounter any issues or have questions regarding your O-NOORUS D4 amplifier, please contact our customer support team for assistance. Contact information can typically be found on the product packaging, the official O-NOORUS website, or through your retailer.