Power supply selection:The power supply range of this product is DC12-24V, compatible with the standard 5.5 x 2.5MM.The power adapter plug is recommended to use a 12V/24V standard power adapter with a current output of more than 10A. 1) The size of the power supply is related to the power of the speaker used. For example, if an 8 ohm 100W speaker is used with a 24V power supply, the current is at least 6A or more, and the current is too small. Sound caton may occur. Reducing the volume and reducing the output power can solve this problem. 2) The power supply voltage cannot be higher than 26V, and if it is higher than 26V, the circuit board will be burned. 3) If the power amplifier board restarts after the volume is turned up during playback, the power supply is insufficient and the power supply with a larger output current can be replaced. Speaker selection: The power amplifier of this product can continuously output 100W x 2 power, and the speakers of 20W~200W can be pushed. It is recommended to use 8 ohm or 4 ohm speakers. If the power is a speaker within 100W, appropriately reduce the power supply voltage (such as 12V power supply) or turn down the playback volume! The larger the power supply voltage of the speaker 100W, the better (within 26V).If there is a "" in the speaker playing music, the first consideration is that the power supply is insufficient and a larger power supply is used for power supply. Second, consider the thermal protection of the power amplifier, strengthen heat dissipation or reduce the playback volume. If multiple speakers are used in parallel, the total impedance of the speakers in parallel must be controlled at more than 4 ohms. If the impedance is too small, the power amplifier can easily enter the overcurrent protection state. TPA3116 dual-core digital Class D bluetooth power amplifier board Amplifier chip:TPA3116x2 Output power: 2x100W / 4 Ohm, 50Wx2/ 8 Ohm, at DC24V Speaker Load: 20-200W, 4-8 Ohm Bluetooth version: Bluetooth 5.0 version Bluetooth transmission distance: 10 meters in the open without barrier. Working : Class D Frequency response: 20Hz to 20kHz Working voltage: DC18V-DC24V, 3A or more, recommend DC24V 6A switch supply power.(5.5 x 2.5MM) Size:91 x 70 x 18MM Signal problem: This product uses a PCB antenna. Under unobstructed conditions, the visible distance of the connection can reach 10 meters. If you can't find Bluetooth when using it, or you can't connect to Bluetooth, then consider it a signal problem. 1) Be sure to from the router when using it. 2) Avoid using it on metal countertops, which will affect the PCB antenna signal. 3) To modify the speaker, if it is a metal shell, be sure to draw the antenna out of the shell, the metal will block the signal. Color: Black material: plastic Package Contents: 1Pcs TPA3116 Bluetooth Amplifier Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.