Daakro ZK-MT21 2.1 Channel Bluetooth Amplifier Board Instruction Manual

Introduction

This manual provides detailed instructions for the setup, operation, and maintenance of your Daakro ZK-MT21 2.1 Channel Bluetooth Amplifier Board. Designed for DIY audio enthusiasts, this board offers high-fidelity sound with versatile input options and comprehensive protection features. Please read this manual thoroughly before use to ensure proper functionality and longevity of your device.

What's in the Box

Upon opening the package, verify that all components are present:

• Amplifier Board
• Screwdriver (for wiring connections)
• DC Power Adapter Connector
• Knobs (5 pieces)
• Mounting Hardware (screws, standoffs)

Image: The Daakro ZK-MT21 amplifier board and included accessories, including a screwdriver, DC power connector, knobs, and mounting hardware.

Key Features

• Dual HiFi Chip Technology: Utilizes two HiFi amplifier chips with PurePath technology for ultra-high resolution, ultra-low distortion, and high-fidelity sound.
• 2.1-Channel Configuration: Supports left channel (50W), right channel (50W), and subwoofer output (up to 100W) for an immersive sound experience.
• Dual Audio Input Modes: Features both Bluetooth 5.0 for wireless connectivity and a traditional AUX input for wired audio sources.
• Wide Application Voltage: Compatible with DC 9V to 24V power supplies, suitable for 30-200W, 4-8Ω speakers.
• Comprehensive Protection: Built-in over-voltage, under-voltage, over-temperature, short-circuit, and reverse connection protection mechanisms ensure device safety.

Setup Instructions

Follow these steps to correctly set up your ZK-MT21 amplifier board:

1. Speaker Connections

1. Identify the speaker terminals on the amplifier board. There are terminals for Left (L), Right (R), and Subwoofer (S) channels, each with positive (+) and negative (-) connections.
2. Connect your speakers to the corresponding terminals. Ensure correct polarity (positive to positive, negative to negative) for optimal sound quality.
3. Use the provided screwdriver to securely fasten the speaker wires into the terminals.

Image: A detailed diagram illustrating the connection points for the subwoofer, right channel, left channel, Bluetooth 5.0 antenna, AUX input, and DC 12-24V power input on the ZK-MT21 amplifier board. Key components like the low noise front stage operational amplifier, large-capacity energy storage capacitor, and heat sinks are also labeled.

2. Power Supply Connection

1. Connect a DC power supply (9V-24V) to the DC 12-24V input terminal. The provided DC power adapter connector can be used for this purpose.
2. Ensure the power supply matches the voltage requirements of your speakers and the amplifier board for optimal performance.

Important: Optimal audio output requires the correct combination of adequate audio input with appropriate power supply voltage and current. Different loudspeaker impedances affect relative sound power. A loudspeaker with a higher impedance will produce less relative sound power with sufficient voltage and current. Please be aware of these factors to optimize your audio experience.

3. Audio Input

The ZK-MT21 supports two audio input modes:

• Bluetooth 5.0: For wireless connection, ensure the Bluetooth antenna is properly connected (if external).
• AUX Input: Connect your audio source (e.g., phone, TV, laptop) using a 3.5mm audio cable to the AUX-IN port.

Image: The ZK-MT21 amplifier board with icons representing Bluetooth 5.0 input and 3.5mm AUX input, along with devices like a tablet, mobile phone, and computer, illustrating its versatile connectivity.

4. Attaching Knobs

Gently push the provided knobs onto the control shafts for Subwoofer Frequency, Subwoofer Volume, R&L Treble, R&L Bass, and Main Volume.

Image: The ZK-MT21 amplifier board shown with all five control knobs attached, highlighting the main volume, R&L bass, R&L treble, subwoofer volume, and subwoofer frequency controls.

Setup Video Guide

Watch this video for a visual guide on connecting the speakers and power to the amplifier board.

Operating Instructions

Once the amplifier board is set up, follow these steps to operate it:

1. Power On

Flip the power switch to the "ON" position. A blue indicator light will illuminate, indicating the board is powered on.

2. Bluetooth Pairing

1. Ensure your audio source device (e.g., smartphone) has Bluetooth enabled.
2. Search for available Bluetooth devices. The amplifier board will appear as "BT SZM" or a similar identifier.
3. Select the device to pair. Once connected, you can stream audio wirelessly.

Image: The ZK-MT21 amplifier board wirelessly connected to a smartphone via Bluetooth, demonstrating the range of up to 16.4 feet (5 meters).

3. AUX Input Usage

If using the AUX input, simply connect your audio device with a 3.5mm cable. The board will automatically switch to AUX mode if a cable is detected.

4. Adjusting Audio Controls

• Main Volume: Adjusts the overall output volume.
• R&L Bass/Treble: Controls the bass and treble levels for the left and right channels.
• Subwoofer Volume/Frequency: Adjusts the subwoofer's volume and crossover frequency.

Experiment with these controls to achieve your desired sound profile.

Operation Video Guide

This video demonstrates the operation of the amplifier board, including power-on, Bluetooth pairing, and adjusting the various audio controls.

Specifications

Image: A table detailing the power output of the ZK-MT21 amplifier board based on input voltage and speaker impedance for both R&L channels and the subwoofer output. For example, at 24V with 4Ω speakers, R&L channels output 50W each, and the subwoofer outputs 100W.

Troubleshooting

If you encounter issues with your ZK-MT21 amplifier board, refer to the following common troubleshooting steps:

• No Power:
  • Ensure the power supply is correctly connected and within the 9V-24V DC range.
  • Check if the power switch is in the "ON" position.
  • Verify the power adapter is functioning correctly.
• No Sound Output:
  • Confirm speaker wires are securely connected to the correct terminals with proper polarity.
  • Check if the audio source is playing and its volume is turned up.
  • Ensure the amplifier's main volume knob is turned up.
  • If using Bluetooth, verify the device is successfully paired and connected.
  • If using AUX, ensure the cable is fully inserted and functional.
• Distorted Sound:
  • Reduce the input volume from your audio source.
  • Lower the amplifier's main volume.
  • Check speaker impedance compatibility (4-8Ω).
  • Ensure the power supply is stable and provides sufficient current.
• Bluetooth Disconnection:
  • Ensure the audio source device is within the Bluetooth range (up to 16.4 feet/5 meters).
  • Avoid obstacles that may interfere with the Bluetooth signal.
  • Try unpairing and re-pairing the device.

Maintenance

To ensure the longevity and optimal performance of your ZK-MT21 amplifier board, follow these maintenance guidelines:

• Cleaning: Use a soft, dry cloth to wipe the surface of the board. Avoid using liquid cleaners or solvents, as they may damage the components.
• Ventilation: Ensure the amplifier board is placed in a well-ventilated area to prevent overheating. Do not block the heat sinks.
• Storage: When not in use for extended periods, store the board in a cool, dry place away from direct sunlight and extreme temperatures.
• Connections: Periodically check all wiring connections to ensure they are secure and free from corrosion.

Warranty and Support

Daakro is committed to providing high-quality audio-visual systems. Your ZK-MT21 amplifier board comes with a 30-day warranty. For any questions, technical assistance, or support, please contact our online customer service. We aim for 100% customer satisfaction and are available to assist you within 24 hours.

For more information and to explore other Daakro products, visit the Daakro Store on Amazon.