Nobsound NS-04G PRO 2.0 Channel HiFi Stereo Digital Power Amplifier User Manual

1. Introduction

The Nobsound NS-04G PRO is a compact 2.0 channel HiFi stereo digital power amplifier designed for home audio systems. It features dual TPA3116 IC chips, providing a maximum output of 100W + 100W (at 4Ω load). This amplifier is compatible with various audio sources via standard stereo RCA input and is suitable for driving passive bookshelf, computer, desktop, or floor-standing speakers. Its design focuses on clear sound reproduction with low distortion and dynamic balance.

Image: The Nobsound NS-04G PRO amplifier, highlighting the internal TPA3116D2 chips responsible for its audio processing capabilities.

2. What's in the Box

Please check the package contents upon unboxing to ensure all items are present:

• 1 x Nobsound NS-04G PRO Amplifier
• 1 x 19V Power Supply
• 1 x User Manual

Image: Contents of the Nobsound NS-04G PRO package, including the amplifier unit, its power supply, and the user manual.

3. Product Overview

The Nobsound NS-04G PRO amplifier features a straightforward design for ease of use. Below is an overview of its front and rear panels:

Image: Detailed diagram showing the front and rear panels of the Nobsound NS-04G PRO amplifier, indicating input, output, power, and control elements.

Front Panel

• Power Indicator: A small LED light that illuminates when the amplifier is powered on.
• Volume Knob / Power Switch: This multi-function knob controls the audio output level and also serves as the power on/off switch. Turn clockwise to increase volume and power on, counter-clockwise to decrease volume and power off.

Rear Panel

• RCA Input (L/R): Standard stereo RCA jacks for connecting audio sources such as phones, TVs, MP3 players, CD players, DACs, or computers.
• Speaker Output (L/R): Binding posts for connecting passive speakers. Ensure correct polarity (+ to + and - to -) for optimal sound.
• DC 12V-24V Power Input: Jack for connecting the provided 19V power adapter.

4. Setup

Follow these steps to set up your Nobsound NS-04G PRO amplifier:

1. Connect Speakers: Connect your passive speakers to the speaker output binding posts on the rear panel. Ensure the positive (+) terminal of the amplifier connects to the positive (+) terminal of the speaker, and the negative (-) terminal connects to the negative (-) terminal.
2. Connect Audio Source: Connect your audio source (e.g., phone, TV, CD player) to the RCA input jacks on the rear panel using an RCA cable. Match the left (L) and right (R) channels.
3. Connect Power: Connect the provided 19V power adapter to the DC 12V-24V power input jack on the rear panel, then plug the adapter into a wall outlet.
4. Power On: Turn the volume knob clockwise to power on the amplifier. The power indicator light on the front panel will illuminate.

Image: The Nobsound NS-04G PRO amplifier set up with two passive speakers and an audio source, demonstrating a typical connection.

5. Operating Instructions

Once the amplifier is set up, operating it is straightforward:

• Power On/Off: Rotate the volume knob clockwise to turn on the amplifier. Rotate it counter-clockwise until it clicks to turn off the amplifier.
• Adjust Volume: After powering on, rotate the volume knob clockwise to increase the volume and counter-clockwise to decrease it. Start with a low volume and gradually increase it to a comfortable listening level.
• Audio Playback: Ensure your audio source is playing content. The amplifier will output the sound through the connected speakers.

Image: A close-up view of the volume knob on the Nobsound NS-04G PRO, which also functions as the power switch.

6. Specifications

7. Troubleshooting

If you encounter issues with your Nobsound NS-04G PRO amplifier, refer to the following common problems and solutions:

• No Sound or Low Volume:
  • Ensure all cables (power, audio input, speaker wires) are securely connected.
  • Verify the audio source is playing and its volume is turned up.
  • Check the amplifier's volume knob and ensure it is turned up sufficiently.
  • Confirm speaker wires are connected with correct polarity (+ to + and - to -).
• Sound Only from One Speaker:
  • Check the RCA input cable connections for both left and right channels.
  • Inspect speaker wire connections for the affected channel.
  • Test with a different audio source or cable to rule out external equipment issues.
• Distortion or Poor Sound Quality at Higher Volumes:
  • The provided 19V power supply may limit the amplifier's full potential. For optimal performance and higher output without distortion, consider upgrading to a 24V power supply with a higher wattage (e.g., 240W), ensuring it is compatible with the amplifier's DC input specifications.
  • Ensure your speakers are rated to handle the amplifier's output power.
• High-Pitched Screeching Sound:
  • This can indicate interference or a faulty component. Try isolating the amplifier from other electronic devices.
  • Ensure all connections are tight and free from shorts.
  • If the issue persists, contact customer support.
• Pop Sound at Power On/Off:
  • A slight pop sound upon power cycling can be normal for some amplifiers. If it is excessively loud or concerning, ensure the volume is turned down before powering on or off.
• Volume Knob Too Sensitive:
  • The volume control may be highly reactive. Make small, precise adjustments to achieve the desired volume level.

8. Maintenance

To ensure the longevity and optimal performance of your Nobsound NS-04G PRO amplifier, follow these maintenance guidelines:

• Cleaning: Use a soft, dry cloth to wipe the exterior of the amplifier. Avoid using liquid cleaners, aerosols, or solvents, as they may damage the finish or internal components.
• Placement: Place the amplifier in a well-ventilated area to prevent overheating. Avoid direct sunlight, heat sources, and areas with high humidity or dust.
• Handling: Handle the amplifier with care. Avoid dropping it or subjecting it to strong impacts.
• Power Off When Not in Use: For extended periods of inactivity, power off the amplifier and unplug it from the wall outlet.

9. Warranty and Support

Nobsound products are designed for reliability and performance. For specific warranty details, please refer to the warranty card included with your product or visit the official Douk Audio website. If you encounter any issues not covered in this manual or require further assistance, please contact Nobsound customer support through the retailer where you purchased the product or via the contact information provided on the official Douk Audio website (www.doukaudio.com).