DAJUNGUO S350HS TPA3251 Bluetooth Power Amplifier Board User Manual

1. Introduction

Thank you for choosing the DAJUNGUO S350HS TPA3251 Bluetooth Power Amplifier Board. This high-fidelity 2.1 channel audio power amplifier module is designed to deliver powerful and clear sound with a maximum output of 220W x 2 for stereo channels and 350W for the subwoofer. Featuring the advanced TPA3251 chip solution, it supports multiple input methods including Bluetooth, AUX, and USB drive, making it versatile for various audio setups. This manual provides detailed instructions for safe and optimal use of your amplifier board.

2. Safety Information

• Ensure the power supply is within the specified DC 12-38V range and provides above 10A current. Using an incorrect power supply can damage the device.
• Connect the power supply securely. The gold-plated high-current shielded DC socket is designed for safety, preventing sparks. Use a 5.5 * 2.5mm male plug or a DC terminal for connection.
• The S350HS amplifier board incorporates multiple protection mechanisms including short circuit protection, overcurrent protection, overheating protection, and anti-reverse protection. In case of an overload, the device will report a fault condition to protect itself from damage.
• Do not expose the device to moisture or extreme temperatures.
• Do not attempt to disassemble or modify the amplifier board, as this may void the warranty and pose safety risks.

3. Package Contents

Please check the package for the following items:

• 1 x DAJUNGUO S350HS Bluetooth Power Amplifier Board
• 1 x Screwdriver

4. Product Overview

The DAJUNGUO S350HS is a powerful 2.1 channel amplifier board designed for high-quality audio reproduction. Below is a diagram highlighting its key components and controls.

4.1. Features

• High-Fidelity Audio: Utilizes TPA3251 HIFI chip for superior sound quality.
• 2.1 Channel Output: Dedicated outputs for left, right, and subwoofer channels.
• High Power Output: Up to 220W x 2 (L&R) + 350W (Subwoofer).
• Multiple Input Options: Bluetooth 5.1, AUX (3.5mm), and USB Flash Drive.
• Tone Control: Independent Treble and Bass adjustment for stereo channels, and Subwoofer Volume and Frequency control.
• Robust Protection: Built-in overvoltage, undervoltage, clipping, short circuit, and overheating protection.
• APP Control: Supports control via a dedicated application for custom Bluetooth name, password, and prompt tone settings.

4.2. Controls and Ports

• AUX Input: 3.5mm jack for wired audio sources.
• 2Pin Input Socket (DC12-38V): Power input terminal (5.5x2.5mm DC socket).
• USB Input: For connecting USB flash drives with audio files.
• Antenna Interface: For Bluetooth antenna.
• Power Switch: To turn the amplifier on/off.
• R&L Bass Knob: Adjusts the bass level for the left and right stereo channels.
• R&L Treble Knob: Adjusts the treble level for the left and right stereo channels.
• Multifunctional Knob: Main volume control.
• Subwoofer Volume Knob: Adjusts the volume level of the subwoofer output.
• Subwoofer Frequency Knob: Adjusts the crossover frequency for the subwoofer.

5. Setup

5.1. Power Connection

1. Ensure the amplifier is switched off.
2. Connect a DC power supply (12-38V, above 10A) to the 2Pin Input Socket. The DC socket specification is 5.5 * 2.5mm. If you do not have a compatible plug, you can use a DC terminal.
3. Verify the connection is secure to prevent sparks.

5.2. Speaker Connection

1. Connect your left and right passive speakers to the L and R output terminals.
2. Connect your passive subwoofer to the S (subwoofer) output terminal.
3. Ensure correct polarity (+/-) for all speaker connections.

5.3. Audio Input Connection

The S350HS supports three input methods:

• Bluetooth: Power on the amplifier. The Bluetooth indicator will flash. Search for 'S350HS' on your device (e.g., smartphone, tablet) and pair. Once paired, the indicator will be solid.
• AUX Input: Connect your audio source (e.g., laptop, TV, mobile phone) to the AUX Input jack using a 3.5mm audio cable.
• USB Input: Insert a USB flash drive containing audio files into the USB port. The amplifier will automatically detect and play the files.

6. Operating Instructions

6.1. Power On/Off

Press the 'POWER' switch on the front panel to turn the amplifier on or off.

6.2. Volume Adjustment

Rotate the large 'Multifunctional Knob' to adjust the overall volume level.

6.3. Tone Control

• R&L Treble: Rotate this knob to increase or decrease the high frequencies of the stereo channels.
• R&L Bass: Rotate this knob to increase or decrease the low frequencies of the stereo channels.
• Subwoofer Volume: Adjusts the output level of the connected subwoofer.
• Subwoofer Frequency: Adjusts the crossover frequency for the subwoofer, allowing you to control which low frequencies are sent to the subwoofer.

6.4. Input Selection

The amplifier automatically prioritizes inputs. For Bluetooth, ensure no AUX or USB is connected. For AUX, ensure no USB is connected. For USB, simply insert the drive.

6.5. APP Control (Unique Function)

The S350HS supports control via a dedicated mobile application. This allows for advanced customization such as changing the Bluetooth name, setting a Bluetooth password, and configuring on/off prompt tones. Refer to the product packaging or seller's website for information on downloading the specific APP.

7. Specifications

8. Troubleshooting

• No Power:
  • Check if the power adapter is correctly connected and providing the specified voltage (DC 12-38V) and current (above 10A).
  • Ensure the power switch is in the 'ON' position.
• No Sound Output:
  • Verify all speaker connections are secure and correctly wired (polarity).
  • Check the audio input source. Ensure the correct input method is active (e.g., Bluetooth paired, AUX cable fully inserted, USB drive recognized).
  • Adjust the main volume knob and individual channel/subwoofer volume knobs.
  • Ensure the audio source device is playing and its volume is turned up.
• Distorted Sound:
  • Reduce the volume from both the amplifier and the audio source. Overdriving the amplifier or speakers can cause distortion.
  • Check speaker impedance compatibility with the amplifier.
  • Ensure audio cables are not damaged and are fully inserted.
  • If using Bluetooth, try moving the audio source closer to the amplifier to improve signal strength.
• Bluetooth Connection Issues:
  • Ensure no other audio inputs (AUX, USB) are active, as they may take priority.
  • Make sure the amplifier is in Bluetooth pairing mode (indicator flashing).
  • Forget the device from your audio source's Bluetooth settings and try pairing again.
  • Ensure the Bluetooth antenna is properly connected.
• Overheating:
  • Ensure the amplifier has adequate ventilation. Do not cover the unit.
  • Reduce the volume or check speaker impedance. Continuous high-power output with incompatible speakers can lead to overheating. The amplifier has built-in overheating protection.

9. User Tips

• Power Supply Quality: Using a high-quality, stable power supply (e.g., a laptop power brick with sufficient amperage) can significantly impact sound quality and amplifier performance.
• Speaker Matching: For optimal performance, ensure your speakers' impedance and power handling capabilities are well-matched to the amplifier's output specifications.
• Cable Quality: Invest in good quality audio cables and speaker wires to minimize signal loss and interference.
• APP Customization: Explore the mobile application (if available for download) to unlock advanced features like custom Bluetooth names and prompt tones, enhancing your user experience.

10. Maintenance

• Cleaning: Use a soft, dry cloth to clean the amplifier board. Do not use liquid cleaners or solvents.
• Storage: When not in use for extended periods, store the amplifier in a cool, dry place away from direct sunlight and dust.
• Ventilation: Ensure the amplifier always has proper ventilation during operation to prevent overheating.

11. Warranty and Support

This product is typically covered by a 90-day free returns policy. For specific warranty details, return procedures, or technical support, please refer to the seller's policy or contact the seller directly through your purchase platform. Keep your purchase receipt or order number handy for any inquiries.