ZK-TB21S 2.1 Channel Bluetooth 5.1 Subwoofer Amplifier Board

Introduction

The ROXIFETA ZK-TB21S is a high-performance 2.1 channel audio power amplifier board designed for home audio systems. Featuring Bluetooth 5.1 connectivity, it allows for wireless audio streaming from compatible devices. With a power output of 50W per main channel and 100W for the subwoofer, it delivers robust and clear sound. This manual provides detailed instructions for setup, operation, and maintenance to ensure optimal performance and longevity of your amplifier board.

Safety Information

• Ensure the power supply voltage is within the specified 12V-24V DC range. Using an incorrect voltage can damage the board.
• Do not expose the amplifier board to moisture, water, or extreme temperatures.
• Avoid touching the circuit board components when the device is powered on.
• Disconnect power before making any connections or disconnections.
• Place the board in a well-ventilated area to prevent overheating.
• Keep out of reach of children.

Product Overview and Components

Familiarize yourself with the various inputs, outputs, and controls on the ZK-TB21S amplifier board.

Figure 1: ZK-TB21S Amplifier Board Layout

This image displays the top view of the ZK-TB21S 2.1 Channel Bluetooth 5.1 Subwoofer Amplifier Board. Key components and controls are visible:

• 1. 12-24V DC Power Input: Located on the left side, this terminal block is for connecting the DC power supply (12V to 24V). Ensure correct polarity (+ and -).
• 2. R&L Channel Speaker Outputs: Positioned next to the power input, these terminals are for connecting the right and left main speakers. Each channel has positive (+) and negative (-) terminals.
• 3. AUX-IN: A 3.5mm audio jack for connecting external audio sources via an auxiliary cable.
• 4. USB-IN: A USB port, typically for digital audio input or potentially for firmware updates/power.
• 5. Main Volume Knob: The largest knob on the right, controls the overall output volume of all channels.
• 6. Treble Knob: Adjusts the high-frequency response of the R&L channels.
• 7. Mid Knob: Adjusts the mid-range frequency response of the R&L channels.
• 8. Bass/Vol Knob (Subwoofer Volume): Controls the volume level of the subwoofer's output.
• 9. Mode Button: Used to switch between different input modes (e.g., Bluetooth, AUX, USB).
• 10. Subwoofer Output Terminals: Located near the Bass/Vol knob, these are for connecting the subwoofer speaker.

Setup Instructions

1. Power Supply Connection:

   Connect a 12V-24V DC power adapter to the "12-24V" input terminals on the board. Ensure correct polarity: positive (+) to positive, negative (-) to negative. A power supply with sufficient current capacity (e.g., 5A or higher for 24V) is recommended for optimal performance.

2. Speaker Connections:
   • Main Speakers (R&L Channel): Connect your passive right and left speakers to the "R&L CHANNEL" output terminals. Observe correct polarity for each speaker (+ to + and - to -).
   • Subwoofer: Connect your passive subwoofer to the "SUBWOOFER" output terminals. Ensure correct polarity.
3. Audio Input Connection:
   • Bluetooth: Power on the board. The board will typically enter Bluetooth pairing mode automatically (indicated by an LED, if present). On your audio source device (smartphone, tablet, PC), search for Bluetooth devices and select "ZK-TB21S" to pair.
   • AUX-IN: Insert a 3.5mm audio cable from your audio source (e.g., MP3 player, computer) into the "AUX-IN" jack.
   • USB-IN: Connect a USB cable from your audio source to the "USB-IN" port.
4. Initial Power On: Once all connections are secure, connect the power adapter to a wall outlet. The board should power on.

Operating Instructions

• Mode Selection: Press the "MODE" button to cycle through available input modes (Bluetooth, AUX, USB). The active mode may be indicated by an LED.
• Volume Adjustment:
  • Main Volume: Rotate the "MAIN VOLUME" knob clockwise to increase volume and counter-clockwise to decrease.
  • Subwoofer Volume (Bass/Vol): Rotate the "BASS/VOL" knob to adjust the subwoofer's output level independently.
• Tone Control:
  • Treble: Rotate the "TREBLE" knob to adjust the high-frequency response.
  • Mid: Rotate the "MID" knob to adjust the mid-range frequency response.
• Bluetooth Operation:

  Once paired, your device will typically reconnect automatically when in range and the amplifier is in Bluetooth mode. If connection fails, try unpairing and re-pairing the device.

Maintenance

• Cleaning: Use a soft, dry cloth to wipe the amplifier board. Do not use liquid cleaners or solvents.
• Ventilation: Ensure adequate airflow around the board to prevent heat buildup, especially during prolonged use.
• Storage: When not in use for extended periods, store the board in a cool, dry place, away from direct sunlight and dust.
• Connections: Periodically check all wire connections to ensure they are secure and free from corrosion.

Troubleshooting

Specifications

Warranty and Support

For warranty information and specific support inquiries, please refer to the documentation provided at the time of purchase or contact your retailer. ROXIFETA is committed to providing high-quality electronic components and customer satisfaction.

For general inquiries or technical assistance, please visit the official ROXIFETA website or contact their customer support channels as listed on their product packaging or website.