CA-AS21 2.1 Channel Digital Power Amplifier Board User Manual

1. Introduction

The Creatall CA-AS21 is a high-performance 2.1 Channel Digital Power Amplifier Board Module designed to enhance your home audio experience. Featuring the TPA3255 amplifier chip, it delivers a powerful output of 220W*2 for left and right channels and 350W for the subwoofer. With versatile input options including Bluetooth, AUX, and USB, along with high and low tone subwoofer regulation, this amplifier ensures exceptional sound quality and immersive audio.

2. Key Features

• High-Fidelity Preamplification: Incorporates six low-noise preamplifier 5532 chips to significantly improve sound quality and volume, offering a substantial gain parameter of 30dB.
• Multiple Input Options: Supports various audio input methods including AUX, Bluetooth 5.1, USB flash drive, and USB sound card for broad compatibility.
• Optimized Power Output: Features a window spray tin design for wiring, which enhances output power and ensures stable performance.
• Advanced Amplifier Chip: Utilizes the TPA3255 high-performance class D amplifier chip, known for its high efficiency and ability to deliver high-end sound quality.
• Comprehensive Control: Equipped with a mechanical switch for direct power off, eliminating the need for long presses and waiting, making operation convenient and fast.
• Robust Protection Mechanisms: Includes anti-reverse connection, undervoltage, overheating, overcurrent, and short circuit protection, with automatic recovery without restarting.

3. Specifications

Image: Product back with English parameters.

Image: CA-AS21 amplifier board with dimensions.

4. Packing List

The following items are included in your package:

Image: Packing List contents.

• CA-AS21 Amplifier Board
• Knobs (6 pieces)
• Power adapter cable
• Screwdriver
• M2*4 Screws
• M2*5+4 Copper Pillars
• M2*18 Copper Pillars

5. Setup Instructions

5.1 Physical Installation

Follow these steps to assemble the amplifier board:

Image: Installation diagram and product accessories.

1. Place the lower cover board at the bottom.
2. Align the PCB (amplifier board) with the lower cover board and secure it using M2*5+4 copper pillars.
3. Attach the upper cover board using M2*4 screws.
4. Install the six control knobs onto their respective shafts.

5.2 Connections

Refer to the diagram below for proper connection of power, audio inputs, and outputs:

Image: Product Introduction with labeled ports.

• Power Input: Connect a DC16-38V/10A power supply to either the 5.5*2.1 DC plug or the 2P terminal.
• Audio Input: Use the AUX port for wired audio input, the USB port for USB flash drives or as a USB sound card, or connect via Bluetooth.
• Audio Output: Connect your subwoofer to the 'Subwoofer' terminal and your left and right speakers to the 'Left channel' and 'Right channel' terminals respectively.
• External Antenna (Optional): If using an external 2.4G antenna (purchased separately), weld it to the antenna base as shown in the diagram below.

Image: External antenna welding example.

Important Power Supply Tip:

For optimal performance, ensure that the audio signal input is sufficiently strong and the power supply voltage/current is adequate. Higher power supply voltage and lower speaker impedance generally result in greater output power. Always verify that your power adapter's capacity exceeds the actual working power requirements of the amplifier.

6. Operating Instructions

6.1 Controls Overview

The amplifier board features several knobs and a multi-function button for precise audio control:

Image: Product Introduction with labeled controls.

• Subwoofer Freq: Adjusts the subwoofer crossover frequency (20-200Hz).
• Subwoofer Volume: Controls the output volume of the subwoofer.
• Treble (R&L Channel): Adjusts the high-frequency output for the left and right channels.
• Bass (R&L Channel): Adjusts the low-frequency output for the left and right channels.
• Main Volume: Controls the overall master volume.

6.2 Multi-function Button (Wheel Shift Button)

The wheel shift button provides convenient control over playback and input modes:

Image: Song cut button and mode button functions.

• Short Press: Play/Pause
• Long Press: Switch input mode (cycles between USB, Bluetooth, AUX)
• Short Press (Left/Right): Previous Song / Next Song
• Long Press (Left/Right): Volume Down / Volume Up

6.3 Bluetooth Pairing

To connect your device via Bluetooth:

Image: APP SETTING INTERFACE for Bluetooth configuration.

1. Ensure the amplifier is in Bluetooth mode (long press the wheel shift button to cycle modes).
2. On your mobile device, search for available Bluetooth devices and select the amplifier's name (e.g., 'Wuzhi Audio').
3. To modify the Bluetooth name: Enter a new BT name in the Wuzhi Audio APP, click the set button. The system will automatically restart. You may need to cancel pairing on your mobile device with the old BT name and then re-pair with the new name.
4. To set a Bluetooth password:
   Method 1 (Default): Turn on the BT password switch in the APP. The default password is '1111'.
   Method 2 (Custom): Turn on the BT password switch, enter your desired password, and click the setting button. The system will restart. Cancel any existing pairing on your mobile device, and you will be prompted to enter the new password when connecting again.

7. Maintenance

• Keep the amplifier board clean and free from dust. Use a soft, dry cloth for cleaning.
• Avoid exposing the device to moisture, extreme temperatures, or direct sunlight.
• Ensure adequate ventilation around the amplifier to prevent overheating.
• Do not attempt to disassemble or repair the unit yourself, as this may void the warranty and cause damage.

8. Troubleshooting

Q: No power or audio output.

A: Check if the power supply is correctly connected and provides the specified voltage (DC16-38V/10A). Ensure all audio cables are securely connected to the correct input/output ports. Verify that the amplifier is switched on.

Q: Distorted sound.

A: Ensure the audio input signal is not too strong or too weak. Check speaker impedance compatibility (3-8 Ω for R&L, 2-8 Ω for subwoofer). Verify that the power supply is stable and sufficient for the output power. Adjust the volume levels on both the amplifier and the source device.

Q: Bluetooth connection issues.

A: Make sure the amplifier is in Bluetooth mode. Try unpairing and re-pairing the device. If a password is set, ensure it is entered correctly. Check for interference from other wireless devices.

Q: Amplifier overheats.

A: Ensure there is sufficient airflow around the amplifier. Do not block the cooling fan. Reduce the volume or output power if operating at high levels for extended periods. The amplifier has built-in overheating protection and will automatically recover.

9. User Tips

• DIY Gain Adjustment: For advanced users, changing the R and L resistors on the board can allow for custom DIY gain adjustments.
• Maximize Output Power: Utilizing an additional level of pre-amplification can help ensure full output power from the amplifier.
• Power Supply Matching: Always match your power adapter's output capabilities to the amplifier's requirements and your speaker's impedance for optimal performance and to prevent damage.

Image: Internal view with sound quality improvement details.

10. Warranty and Support

Creatall products undergo 100% strict inspection and testing before shipment to ensure quality.

• Warranty Period: The product comes with a one-year warranty.
• Defective Goods: If original defective goods are found upon arrival, replacements will be provided within one week.
• Return Policy: Any item must be returned as-is to be eligible for a refund or payment. The buyer is responsible for all freight incurred for returns.

Contact Information:

For technical support or warranty claims, please contact Creatall using the following methods:

• Wechat: zq13827494627
• WhatsApp: +86-13827494627
• Skype: alvacheng1
• E-mail: leo@creatall.com