Wuzhi Audio Bluetooth Digital Power Amplifier Board Module User Manual

1. Introduction

This manual provides detailed instructions for the Wuzhi Audio series of Bluetooth Digital Power Amplifier Board Modules. These modules are designed to provide high-quality audio amplification with various features including Bluetooth connectivity, AUX input, USB sound card functionality, and in some models, tone control. Please read this manual carefully before use to ensure proper installation and operation.

2. Product Comparison

The Wuzhi Audio amplifier board modules come in several variants, each offering distinct features and power outputs. Refer to the table below for a quick comparison:

3. Specifications

Detailed specifications for each model are provided below. Please note that all power supplies should be DC and not connected to AC. Overpressure is not allowed.

ZK-LT21 (2.1 Channel, 15W*2 + 30W Subwoofer)

• Adapter Power Supply: 9-24V/3A
• Bluetooth Version: 5.1
• Audio Input: Bluetooth (BT), AUX, USB, USB Sound Card
• Audio Output: Left Channel 15W + Right Channel 15W + Subwoofer 30W
• Volume Adjustment: Classic mechanical knob (with volume scale), stepless adjustment for R&L Channel and Subwoofer.
• Switch Machine: Classic mechanical switch, one turn for power on/off.
• Adapter Speaker: 10-50W 4-8Ω. Note: If driving a 4Ω speaker, the power supply cannot exceed 12V.
• Protection Mechanism: Overheating, overcurrent, short circuit, anti-static protection.
• Dimensions: 76mm * 60mm * 22mm
• Weight (with packaging): 102g

ZK-302 (2.0 Channel, 30W*2 Stereo)

• Adapter Power Supply: 9-24V/3A
• Bluetooth Version: 5.1
• Audio Input: Bluetooth (BT), AUX, USB, USB Sound Card
• Audio Output: Left Channel 30W + Right Channel 30W
• Volume Adjustment: Classic mechanical knob (with volume scale), stepless adjustment.
• Switch Machine: Classic mechanical switch, one turn for power on/off.
• Adapter Speaker: 10-50W 8Ω. Note: It is recommended to use an 8Ω speaker. If driving a 4Ω speaker, the power supply cannot exceed 12V.
• Protection Mechanism: Overheating, overcurrent, short circuit, anti-static protection.
• Dimensions: 71mm * 50mm * 18mm
• Weight (with packaging): 82g

ZK-302T (2.0 Channel, 30W*2 Stereo with Treble & Bass)

• Adapter Power Supply: 9-24V/3A
• Bluetooth Version: 5.1
• Audio Input: Bluetooth (BT), AUX, USB, USB Sound Card
• Audio Output: Left Channel 30W + Right Channel 30W
• Volume Adjustment: Classic mechanical knobs for Volume, Bass, and Treble (with volume scale), stepless adjustment.
• Switch Machine: Classic mechanical switch, one turn for power on/off.
• Adapter Speaker: 10-50W 8Ω. Note: It is recommended to use an 8Ω speaker. If driving a 4Ω speaker, the power supply cannot exceed 12V.
• Protection Mechanism: Overheating, overcurrent, short circuit, anti-static protection.
• Dimensions: 76mm * 60mm * 20mm
• Weight (with packaging): 106g

ZK-152T (2.0 Channel, 15W*2 Stereo with Treble & Bass)

• Adapter Power Supply: 9-24V/2A
• Bluetooth Version: 5.1
• Audio Input: Bluetooth (BT), AUX, USB, USB Sound Card
• Audio Output: Left Channel 15W + Right Channel 15W
• Volume Adjustment: Classic mechanical knobs for Volume, Bass, and Treble (with volume scale), stepless adjustment.
• Switch Machine: Classic mechanical switch, one turn for power on/off.
• Adapter Speaker: 5-30W 4-8Ω. Note: It is recommended to use an 8Ω speaker. If driving a 4Ω speaker, the power supply cannot exceed 12V.
• Protection Mechanism: Overheating, overcurrent, short circuit, anti-static protection.
• Dimensions: 71mm * 60mm * 22mm
• Weight (with packaging): 98g

ZK-152 (2.0 Channel, 15W*2 Stereo)

• Adapter Power Supply: 9-24V/2A
• Bluetooth Version: 5.1
• Audio Input: Bluetooth (BT), AUX, USB, USB Sound Card
• Audio Output: Left Channel 15W + Right Channel 15W
• Volume Adjustment: Classic mechanical knob (with volume scale), stepless adjustment.
• Switch Machine: Classic mechanical switch, one turn for power on/off.
• Adapter Speaker: 5-30W 4-8Ω. Note: It is recommended to use an 8Ω speaker. If driving a 4Ω speaker, the power supply cannot exceed 12V.
• Protection Mechanism: Overheating, overcurrent, short circuit, anti-static protection.
• Dimensions: 71mm * 50mm * 20mm
• Weight (with packaging): 76g

4. Setup

The amplifier board modules require self-assembly of the protective shell. A screwdriver and power adapter connector are typically included.

4.1 Package Contents

Each module typically includes:

• Digital Power Amplifier Board Module
• Upper cover board
• Lower cover board
• Knobs (quantity varies by model)
• M2*3 screws
• M2*12 or M2*14 or M2*16 copper pillars (quantity varies by model)
• M2*3+3 copper pillars (quantity varies by model)
• Screwdriver (free)
• Power adapter connector (free)

4.2 Assembly Instructions

Follow these steps to assemble the protective shell:

1. Place the lower cover board.
2. Mount the PCB (Printed Circuit Board) onto the lower cover board using the M2*3 screws and M2*3+3 copper pillars.
3. Attach the M2*12/14/16 copper pillars to the PCB.
4. Place the upper cover board on top of the copper pillars and secure it with M2*3 screws.
5. Install the knobs onto their respective shafts.

4.3 Wiring and Connections

Identify the input and output ports on your specific module. The general layout includes:

• DC Power Input (DC9-24V): Connect your DC power adapter here. Ensure the voltage and current match the module's requirements (e.g., 9-24V/2A or 9-24V/3A).
• Speaker Output (+R -R +L -L): Connect your speakers to these terminals. Ensure correct polarity. For ZK-LT21, there are additional terminals for the subwoofer.
• AUX Input (AUX-IN): For wired audio input from devices like phones or MP3 players.
• USB Input (USB-IN): For USB flash disk playback or as a USB sound card input from a computer.

5. Operating Instructions

5.1 Power On/Off and Volume Control

All models feature a classic mechanical knob for volume control. Turn the knob to power on or off the device. A 'pop' sound may indicate power status. Rotate the knob to adjust the volume. Models with Bass and Treble controls (ZK-152T, ZK-302T) have additional mechanical knobs for these adjustments.

5.2 Audio Input Modes

• Bluetooth (BT): The module will automatically enter Bluetooth pairing mode when powered on. Search for the device on your smartphone or other Bluetooth-enabled device and connect.
• AUX Input: Connect your audio source to the AUX-IN port using a 3.5mm audio cable.
• USB Input (USB Flash Disk): Insert a USB flash drive containing audio files into the USB-IN port. The module will automatically play the content.
• USB Sound Card: Connect the module to a computer via the USB-IN port. The module can function as an external sound card for your computer.

5.3 Wuzhi Audio APP Features

All modules support the Wuzhi Audio APP, which offers enhanced control and customization:

• Modify BT Name: Change the Bluetooth name of your module for easy identification, especially when using multiple devices.
• Set BT Password: Add a password to your Bluetooth connection to prevent unauthorized access. This feature can be toggled on/off.
• Adjust Prompt Tone Volume: Customize the volume of system prompt sounds.
• ON/OFF Prompt Tone: Enable or disable system prompt sounds.
• Sleep Aid Function: Access a selection of 10 natural sounds (e.g., Sound bowl, Stream, Wave, Sea wave, Thunderstorm, Bird song, Cry of insects, Frogs, Bonfire, Guqin) with up to 1023 sound combinations to create a natural atmosphere for relaxation and sleep. The APP also includes a timed shutdown function.
• Sound Effect Selection + Custom Sound Effect: Choose from preset sound effects (Popular, Classical, Jazz, Country, Natural, Rock) or create a custom 10-segment equalizer setting to optimize audio output for different speakers and preferences.
• USB Flash Disk Playlist Function: Manage and select songs from a connected USB flash drive, supporting random play and song cutting.

6. Maintenance

To ensure the longevity and optimal performance of your amplifier module:

• Keep the module clean and free from dust. Use a soft, dry cloth for cleaning.
• Avoid exposing the module to moisture, extreme temperatures, or direct sunlight.
• Ensure proper ventilation to prevent overheating.
• Do not attempt to disassemble the PCB beyond the protective shell assembly.

7. Troubleshooting

• No Power: Ensure the DC power adapter is correctly connected and provides the specified voltage and current. Check for loose connections.
• No Sound: Verify speaker connections and polarity. Check audio input source (Bluetooth, AUX, USB) and ensure it is active and properly connected. Adjust volume knob.
• Distorted Sound: Ensure the power supply meets the requirements. Check speaker impedance and power rating. If driving a 4Ω speaker, ensure the power supply does not exceed 12V. Reduce volume if distortion occurs at high levels.
• Bluetooth Connection Issues: Ensure the module is in pairing mode. If a password is set via the APP, ensure it is entered correctly. Try canceling pairing on your mobile device and re-pairing.
• Overheating: Ensure adequate ventilation around the module. Check for proper speaker impedance. The module has built-in overheating protection, which may temporarily shut down the device.
• Other Protection Mechanisms: The module includes overcurrent, short circuit, and anti-static protection. If the module stops functioning unexpectedly, check for short circuits in wiring or excessive current draw.

8. User Tips

• Mechanical Volume Knob: The classic mechanical volume knob provides a tactile experience and allows for precise, stepless volume adjustment. Turning the volume to the lowest setting before powering off can help prevent damage to speakers and the amplifier.
• APP Customization: Utilize the Wuzhi Audio APP to personalize your listening experience. Changing the Bluetooth name can be particularly useful if you own multiple modules or are in an environment with many Bluetooth devices. Experiment with the 10-segment custom sound effects to fine-tune the audio output for your specific speakers.
• Power Supply Caution: Always use a stable DC power supply within the specified voltage range. Overpressure can damage the module. Pay close attention to the maximum recommended voltage when using 4Ω speakers to prevent damage.

9. Warranty and Support

For technical support or warranty inquiries, please contact the seller or manufacturer directly. Keep your purchase records for reference.