Zopsc ZK-MT21 100W Bluetooth Amplifier Board User Manual

1. Introduction

This user manual provides detailed instructions for the installation, operation, and maintenance of your Zopsc ZK-MT21 100W Bluetooth Amplifier Board. Please read this manual thoroughly before using the product to ensure proper function and safety.

2. Safety Information

• Ensure the power supply voltage matches the specified DC12-24V.
• Do not expose the device to moisture or extreme temperatures.
• Avoid short-circuiting the output terminals.
• Disconnect power before making any connections or adjustments.
• This amplifier board includes built-in protection against reverse connection, overheating, overcurrent, and short circuits. However, always exercise caution.

3. Package Contents

Verify that all items are present in the package:

• 1 x Amplifier Board
• 1 x Cover
• 1 x Bottom Plate
• 1 x Adapter (likely power adapter or DC jack adapter)
• 1 x Screwdriver
• 5 x Knob Cover
• 8 x Screw
• 4 x Short Screw Column
• 4 x Long Screw Column

Image: All components included in the ZK-MT21 amplifier board package, neatly arranged.

4. Product Overview

The Zopsc ZK-MT21 is a 2.1 channel Bluetooth 5.0 amplifier board designed for HiFi audio applications. It features adjustable controls for subwoofer frequency, subwoofer volume, left/right channel treble, left/right channel bass, and main volume. It supports both AUX and Bluetooth audio input.

Image: Labeled diagram of the ZK-MT21 amplifier board, showing power input, audio input, speaker outputs, and control knobs for subwoofer frequency, subwoofer volume, left/right channel treble, left/right channel bass, and main volume.

Component Identification:

• Power Input (DC12-24V): Connect the DC power adapter (5.5*2.1DC plug).
• Audio Input (AUX): 3.5mm audio jack for wired audio sources.
• Subwoofer Output: Terminal for connecting a subwoofer speaker.
• Left Channel Output: Terminal for connecting the left speaker.
• Right Channel Output: Terminal for connecting the right speaker.
• Subwoofer Frequency Knob: Adjusts the cutoff frequency for the subwoofer (20-200Hz).
• Subwoofer Volume Knob: Controls the volume level of the subwoofer.
• Treble (R&L Channel) Knob: Adjusts the high-frequency response for left and right channels.
• Bass (R&L Channel) Knob: Adjusts the low-frequency response for left and right channels.
• Main Volume Knob: Controls the overall output volume.
• Bluetooth Antenna: For wireless audio connection.

5. Specifications

6. Setup Instructions

6.1 Assembly

The amplifier board comes with a protective shell (cover and bottom plate) that needs to be assembled. Use the provided screws, screw columns, and screwdriver to secure the board between the cover and bottom plate. Attach the knob covers to the control shafts.

Image: The ZK-MT21 amplifier board, both assembled with its protective casing and as a bare board, illustrating the assembly process.

6.2 Connecting Speakers

1. Identify the Subwoofer, Left Channel, and Right Channel output terminals on the amplifier board (refer to Product Overview).
2. Connect your subwoofer speaker to the "Subwoofer" terminals. Ensure correct polarity (+ to + and - to -).
3. Connect your left channel speaker to the "Left Channel" terminals. Ensure correct polarity.
4. Connect your right channel speaker to the "Right Channel" terminals. Ensure correct polarity.
5. Ensure all speaker wires are securely fastened and do not touch each other to prevent short circuits.

6.3 Connecting Audio Input

The ZK-MT21 supports two audio input methods: Bluetooth and AUX (wired).

6.3.1 AUX Input

• Connect a 3.5mm audio cable from your audio source (e.g., smartphone, MP3 player, computer) to the "Audio Input (AUX)" jack on the amplifier board.

6.3.2 Bluetooth Input

• Ensure the Bluetooth antenna is properly connected (if detachable).
• The amplifier will automatically enter Bluetooth pairing mode when powered on and no AUX cable is connected.
• On your audio source device, search for Bluetooth devices and select "ZK-MT21" to pair.
• A confirmation sound may indicate successful pairing.

6.4 Power Connection

1. Ensure all speaker and audio input connections are made before connecting power.
2. Connect a DC12-24V power adapter (not included, typically 5.5*2.1DC plug) to the "Power Input" jack on the amplifier board.
3. Plug the power adapter into a suitable wall outlet.

7. Operating Instructions

7.1 Power On/Off

• The amplifier powers on automatically when connected to a power source.
• To power off, disconnect the power adapter from the amplifier or the wall outlet.

7.2 Adjusting Audio Settings

Use the control knobs to fine-tune your audio output:

• Main Volume: Rotate the "Main Volume" knob to increase or decrease the overall sound level.
• Subwoofer Volume: Rotate the "Subwoofer Volume" knob to adjust the bass output level.
• Subwoofer Frequency: Rotate the "Subwoofer Frequency" knob to set the crossover point for the subwoofer, typically between 20-200Hz. This determines which low frequencies are sent to the subwoofer.
• Treble (R&L Channel): Rotate the "Treble" knob to adjust the high-frequency response of the left and right speakers.
• Bass (R&L Channel): Rotate the "Bass" knob to adjust the low-frequency response of the left and right speakers.

8. Maintenance

• Keep the amplifier board clean and free from dust. Use a soft, dry cloth for cleaning.
• Do not use liquid cleaners or solvents.
• Ensure adequate ventilation around the amplifier to prevent overheating.
• Avoid placing heavy objects on the amplifier.

9. Troubleshooting

The amplifier board includes built-in protection features for reverse connection, overheating, overcurrent, and short circuits. If the device stops functioning unexpectedly, disconnect power, check all connections, and allow it to cool down before attempting to restart.

10. Warranty and Support

For warranty information or technical support, please refer to the retailer where you purchased the product or contact Zopsc customer service through their official channels. Keep your purchase receipt as proof of purchase.