Package Included:
- 1 x Power Amplifier

Note:
- Optional Colors: Black, Silver. Please choose the color you want when purchasing. Thank you!
- Power supply is not included in the package. Please purchase separately.
- Other items in the pictures are not included.  

Question and answer:
1. How to choose a power supply?
- The power supply with the board is critical. The higher the voltage, the higher the current and the better the output power. If you only have 12V 1A, you can bring a 3-4 inch speaker. If you are 19V 5A or above, there is no problem with 8-10 inches, and the power supply must be highly valued. If the voltage is too low, the sound will be distorted after the sound is amplified. If the current is too small, the speaker will pull the voltage low, work abnormally or the sound quality will deteriorate.
It is recommended to use 18V 19V 24V power supply with current above 3A. If you only have 9V 12V or 1A 2A power supply, it can also be used but the power is small. Please pay attention to the maximum volume when using it, which may affect the sound quality.

2. How to choose a speaker?
- Commonly used speakers are generally 4 ohms or 8 ohms, can not distinguish between positive and negative, the effect is the same.If your speaker power is small, it may be used between 10W-30W. The power supply voltage is small to prevent the amplifier from burning out after burning. For example, select a power supply below 15V.
- If you are a 50W-100w speaker, don't worry about the speaker burnout. You can choose 12-24V power supply. The higher the voltage you choose, the louder the output sound or power.The speaker power is not recommended to exceed 100W, otherwise the sound quality will be affected.

3. How to choose Bluetooth or AUX audio input mode?
- This audio amplifier module follows the principle of hardware connection first.A successful USB connection is in USB mode, and AUX insertion is in AUX mode.If the USB is not connected and AUX is not plugged in, it is in bluetooth mode, which supports automatic re-connection.Mode toggle with mode prompt.When choosing USB audio input mode, it is important to note that USB can directly connect to the computer and other devices with USB audio output without installing a driver.USB input is lossless input, good sound quality, no interference, no noise.

4. When the sound becomes louder, the phenomenon of turbid sound appears.
- The sound is distorted. Please change the adapter power supply with a higher voltage rating.

5. After the sound becomes louder, the sound is stuck.
- The input power is insufficient, and the power supply itself is intermittently powered off. Please replace the power supply with a larger power.
Or the output power is too large, the power amplifier board is seriously heated, and thermal protection occurs, reducing power usage or enhancing heat dissipation.