1. Introduction
This manual provides detailed instructions for the diymore ZK-Series Bluetooth Audio Digital Power Amplifier Board Modules, including models ZK-302, ZK-302T, ZK-LT21, ZK-152, and ZK-152T. These modules are designed for various audio applications, offering stereo output with Bluetooth connectivity, AUX input, USB drive, and USB sound card capabilities. Please read this manual thoroughly before installation and operation to ensure proper use and optimal performance.
2. Model Comparison
The ZK-Series offers several models with varying features and power outputs. Refer to the table below for a detailed comparison:
| Feature | ZK-152 | ZK-152T | ZK-302 | ZK-302T | ZK-LT21 |
|---|---|---|---|---|---|
| Audio Input | BT+AUX+USB+USB sound card | ||||
| Channels | 2.0 | 2.0 | 2.1 | ||
| Power Output | 15W+15W | 15W+15W | 30W+30W | 30W+30W | 15W+15W+30W |
| Treble & Bass Control | No | Yes | No | Yes | No |
| Power Supply | 9-24V/2A | 9-24V/3A | |||
| Adapter Speaker | 5-30W 4-8Ω | 10-50W 4-8Ω | |||
| Protection | Overheating, overcurrent, short circuit, anti-static protection | ||||
| Size (mm) | 71*50*20 | 71*60*22 | 76*50*18 | 76*60*20 | 76*60*22 |
| Weight (with packaging) | 76g | 98g | 82g | 106g | 102g |
3. Setup and Assembly
The amplifier board modules are shipped unassembled and require self-assembly of the protective shell. Follow the diagrams below for proper installation.
3.1 General Assembly Instructions
Each module typically includes an upper cover board, a PCB (Printed Circuit Board), a lower cover board, copper pillars, and screws. A screwdriver and power adapter cable are usually provided.
- Place the PCB onto the lower cover board, aligning the screw holes.
- Insert the copper pillars into the designated holes on the PCB and lower cover board.
- Place the upper cover board on top of the copper pillars, aligning the holes.
- Secure the assembly with the provided screws.
- Attach the knobs to the potentiometers (volume, bass, treble) if applicable to your model.
3.2 Model-Specific Installation Diagrams
ZK-LT21 Installation
ZK-302 Installation
ZK-302T Installation
ZK-152T Installation
ZK-152 Installation
4. Operation
4.1 Basic Function Introduction
The amplifier modules support multiple audio input methods and provide clear audio output. Connect your speakers and power supply according to the diagrams below.
ZK-LT21 Function Overview
- AUX Input: Connect external audio sources via a 3.5mm audio jack.
- USB-IN: Supports USB flash disk and USB sound card input.
- Power Input: DC 9-24V via a 5.5x2.1DC plug.
- R&L Channel Volume Knob: Adjusts the volume for the right and left stereo channels.
- Subwoofer Volume Knob: Adjusts the volume for the subwoofer channel.
ZK-302 Function Overview
- AUX Input: Connect external audio sources.
- USB-IN: Supports USB flash disk and USB sound card input.
- Power Input: DC 9-24V via a 5.5x2.1DC plug.
- Mechanical Volume Knob: Controls the overall volume.
ZK-302T Function Overview
- AUX Input: Connect external audio sources.
- USB-IN: Supports USB flash disk and USB sound card input.
- Power Input: DC 9-24V via a 5.5x2.1DC plug.
- Volume Knob: Controls overall volume.
- Bass Knob: Adjusts bass levels.
- Treble Knob: Adjusts treble levels.
ZK-152T Function Overview
- AUX Input: Connect external audio sources.
- USB-IN: Supports USB flash disk and USB sound card input.
- Power Input: DC 9-24V via a 5.5x2.1DC plug.
- Volume Knob: Controls overall volume.
- Bass Knob: Adjusts bass levels.
- Treble Knob: Adjusts treble levels.
ZK-152 Function Overview
- AUX Input: Connect external audio sources.
- USB-IN: Supports USB flash disk and USB sound card input.
- Power Input: DC 9-24V via a 5.5x2.1DC plug.
- Mechanical Volume Knob: Controls the overall volume.
4.2 Mechanical Volume Knob
The classic mechanical volume knob provides a tactile experience and precise control. Turning the knob will produce a "pop" sound prompt when starting or shutting down the device.
- Volume Scale: Allows you to visually estimate the current volume level.
- Power On/Off: Turn the volume knob to the lowest setting to turn off the device. This prevents damage to speakers and the amplifier.
- Quick Switch: The mechanical switch turns off without long pressing, offering convenient and fast operation.
- Stepless Tuning: Provides real stepless tuning, not digital multi-stage grading adjustment, for smooth volume control.
4.3 Wuzhi Audio APP Features
Enhance your audio experience with the Wuzhi Audio APP, available for all ZK-Series models. The APP offers comprehensive control and customization options.
- Modify BT Name: Change the Bluetooth name of each product for easy identification, especially when using multiple modules.
- Set BT Password: Modify the Bluetooth connection password to prevent unauthorized access. This function can also be turned off.
- Adjust Prompt Tone Volume: Customize the volume of system prompt tones.
- ON/OFF Prompt Tone: Enable or disable system prompt tones.
- Lullaby + Timed Shutdown: Utilize lullaby features and set a timed shutdown for convenience.
- Sound Effect Adjustment: Access custom 10-segment sound effects and arbitrary adjustments to optimize audio for different speakers.
- USB Flash Disk Playlist Function: Open the playlist of a connected USB flash disk, select music, and support shaking to cut songs.
APP Setting Interface
BT Name Modification Steps:
- Enter a new Bluetooth name in the APP.
- Click the "set" button.
- The system will automatically restart.
- Cancel pairing of your mobile device with the original Bluetooth name.
- Find and re-pair with the new Bluetooth name.
BT Password Setting Steps:
- Method 1: Turn on the BT password switch. Use the default password "1111".
- Method 2: Turn on the BT password switch. Enter your desired password. Click the setting button. The system will restart automatically. Cancel pairing, and you will be prompted to enter the new password when connecting again.
Sound Effect Customization
The APP supports custom 10-segment sound effects and arbitrary adjustment to compensate for speaker deficiencies, allowing you to achieve optimal sound effects.
5. Specifications
Detailed specifications for the ZK-Series amplifier modules are provided below. For a quick comparison, refer to the Model Comparison table in Section 2.
5.1 ZK-152 Product Parameters
| Parameter | Value |
|---|---|
| Model | ZK-152 |
| Name | 2.0, 15Wx2 Stereo BT audio power amplifier |
| Adaptive Power Supply | 9-24V/2A (Do not connect to AC) |
| BT Version | 5.1 |
| Audio Input | 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 on and off, without long press and wait. |
| Adaptive Horn | 5-30W 4-8Ω |
| Protection Mechanism | Overheating, overcurrent, short circuit, anti-static protection |
| Characteristic Function | Support Wuzhi Audio APP. Modify Bluetooth name, password setting, prompt tone volume adjustment, on / off prompt tone, lullaby, sound effect selection + custom sound effect, USB flash disk playlist. |
| Size | 71*50*20mm |
| Product Weight (Net) | 40g |
| Weight (with package) | 76g |
Note: It is recommended to equip with an 8Ω horn and a power supply of 9-24VDC. Overpressure is not allowed. If a 4Ω horn is driven, the power supply shall not exceed 12V.
5.2 ZK-LT21 Product Parameters
| Parameter | Value |
|---|---|
| Model | ZK-LT21 |
| Name | 2.1, 15WX2+30W Bluetooth audio power amplifier with subwoofer |
| Adaptive Power Supply | 9-24V/3A (Do not connect to AC) |
| BT Version | 5.1 |
| Audio Input | 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 |
| Switch Machine | Classic mechanical switch, one turn on and off, without long press and wait. |
| Adapter Speaker | 10-50W 4-8Ω |
| Protection Mechanism | Overheating, overcurrent, short circuit, anti-static protection |
| Characteristic Function | Support Wuzhi Audio APP. Modify Bluetooth name, password setting, volume adjustment of prompt sound, on/off prompt sound, sleep aid, sound effect selection + custom sound effect, U disk playlist. |
| Dimensions | 76*60*22mm |
| Product Weight (Net) | 66g |
| Weight (with package) | 102g |
Note: It is recommended to use an 8Ω speaker and a power supply of 9-24VDC. Overpressure is not allowed. If a 4Ω speaker is driven, the power supply shall not exceed 12V.
5.3 ZK-302 Product Parameters
| Parameter | Value |
|---|---|
| Model | ZK-302 |
| Name | 2.0, 30WX2 Stereo Bluetooth Audio Power Amplifier |
| Adaptive Power Supply | 9-24V/3A (Do not connect to AC) |
| BT Version | 5.1 |
| Audio Input | 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 on and off, without long press and wait. |
| Adapter Speaker | 10-50W 8Ω |
| Protection Mechanism | Overheating, overcurrent, short circuit, anti-static protection |
| Characteristic Function | Support Wuzhi Audio APP. Modify Bluetooth name, password setting, volume adjustment of prompt sound, on/off prompt sound, sleep aid, sound effect selection + custom sound effect, U disk playlist. |
| Dimensions | 71*50*18mm |
| Product Weight (Net) | 45g |
| Weight (with package) | 82g |
Note: It is recommended to use an 8Ω speaker and a power supply of 9-24VDC. Overpressure is not allowed. If a 4Ω speaker is driven, the power supply shall not exceed 12V.
5.4 ZK-302T Product Parameters
| Parameter | Value |
|---|---|
| Model | ZK-302T |
| Name | 2.0, 30WX2 Bluetooth audio power amplifier with high and low bass adjustment |
| Adaptive Power Supply | 9-24V/3A (Do not connect to AC) |
| BT Version | 5.1 |
| Audio Input | 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 on and off, without long press and wait. |
| Adapter Speaker | 10-50W 8Ω |
| Protection Mechanism | Overheating, overcurrent, short circuit, anti-static protection |
| Characteristic Function | Support Wuzhi Audio APP. Modify Bluetooth name, password setting, volume adjustment of prompt sound, on/off prompt sound, sleep aid, sound effect selection + custom sound effect, U disk playlist. |
| Dimensions | 76*60*20mm |
| Product Weight (Net) | 71g |
| Weight (with package) | 106g |
Note: It is recommended to use an 8Ω speaker and a power supply of 9-24VDC. Overpressure is not allowed. If a 4Ω speaker is driven, the power supply shall not exceed 12V.
5.5 ZK-152T Product Parameters
| Parameter | Value |
|---|---|
| Model | ZK-152T |
| Name | 2.0, 15WX2 Bluetooth audio power amplifier with high and low pitch |
| Adaptive Power Supply | 9-24V/2A (Do not connect to AC) |
| BT Version | 5.1 |
| Audio Input | 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 on and off, without long press and wait. |
| Adapter Speaker | 5-30W 4-8Ω |
| Protection Mechanism | Overheating, overcurrent, short circuit, anti-static protection |
| Characteristic Function | Support Wuzhi Audio APP. Modify Bluetooth name, password setting, volume adjustment of prompt sound, on/off prompt sound, sleep aid, sound effect selection + custom sound effect, U disk playlist. |
| Dimensions | 71*60*20mm |
| Product Weight (Net) | 62g |
| Weight (with package) | 98g |
Note: It is recommended to use an 8Ω speaker and a power supply of 9-24VDC. Overpressure is not allowed. If a 4Ω speaker is driven, the power supply shall not exceed 12V.
6. Troubleshooting
This section addresses common issues you might encounter with your amplifier module.
| Problem | Possible Cause | Solution |
|---|---|---|
| No sound output |
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| Distorted sound |
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| Bluetooth connection issues |
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| Module shuts down unexpectedly |
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7. Maintenance
- Cleaning: Use a soft, dry cloth to clean the module. Avoid using liquids or abrasive cleaners.
- Environment: Operate the module in a dry, well-ventilated area. Avoid extreme temperatures, humidity, and direct sunlight.
- Connections: Periodically check all connections (power, audio, speakers) to ensure they are secure and free from corrosion.
- Storage: If storing the module for an extended period, disconnect the power supply and store it in a cool, dry place.
8. User Tips
- For optimal sound quality, use high-quality audio cables and speakers that match the amplifier's specifications.
- Experiment with the Wuzhi Audio APP's sound effect adjustments to find the best audio profile for your speakers and listening preferences.
- When using a USB flash disk, ensure it is formatted correctly and contains compatible audio files.
- Always ensure the power supply is stable and within the recommended voltage and current range to prevent damage and ensure consistent performance.
- If you experience any "pop" sounds during startup/shutdown, this is normal for the mechanical volume knob and indicates proper function.
9. Warranty and Support
For detailed warranty information and technical support, please refer to the official product documentation or contact the seller. A digital user manual in PDF format is available for download:
For further assistance, please reach out to the manufacturer or your point of purchase.
