[HIFI Stereo] High quality dual channel power amplifier board for HIFI music. With AUX and Bluetooth two audio input methods, 2-in-1. 5.0 Bluetooth version, the transmission efficiency is higher, the transmission distance is farther. With a filter inductor, the sound is round and clear.[Protection Mechanism] The TPA3116D2 devices feature short-circuit and thermal protection as well as overvoltage, undervoltage, and DC protection to prevent total failure. In the event of an overload, the device reports the fault condition to the processor to protect itself from damage.[High Performance] The TPA3116D2 is a Class D amplifier IC from TI that has very high index parameters. Advanced oscillator / PLL circuit uses multiple switching frequency options to reject AM interference. The modulation frequency can be up to 1.2MHZ, and the high power output distortion is less than 0.1%. This helps prevent noise.[High Quality] It adopts copper DC connector and fence type terminal. It can withstand large current, no heat, no damage to the wire. Free DC head lead, compatible with the input power interface of this product, even if you dont have a DC head adapter or battery, it can be easily wired.[Application] With bass, treble and volume control, easy to adjust volume, enjoy the music tone what you want. TDA3116D2 is widely used in store solicitation, home theater, square speakers, etc.due to its excellent performance and comprehensive cost performance. Product Description Blue tooth 5.0 audio amplifier board parameter Model: ZK-TB21Chip: TPA3116D2 (With AM interference supperession)Blue tooth Version: 5.0 (Without occlusion 10m)Audio Input: AUX + BluetoothChannel: 2.1 StereoAdaption Supply Voltage: 12-24V / 5A aboveSpeaker: 20-100W, 4-8OhmOutput Power: max 50W R&L channel; max 100W subwooferProtection Mechanism: overheating, undervoltage, overheating, DC detection, short circuit protection Package Including: 1 * Amplifier board blue tooth 5.01 * Shell (upper+lower)1 * Screwdriver1 * Terminal4 * Long copper pillar4 * Short copper pillar5 * Knob cap8 * Screw ZK-TB21 200W Blue tooth Subwoofer Amplifier Board with Treble and Bass Notice: To have enough output power if the audio input is sufficient and the supply voltage/current is sufficient. The power supply voltage is higher and the relative power will be larger. The speakers with different impedances will have different output power. In the case of sufficient voltage and current, the larger the ohms of the horn, the smaller the relative sound power. Please ensure that the power of the adaptor is greater than the actual working power of the amplifier. With dual TPA3116D2 chips TPA3116 D2 Is A Class D Power Amplifier IC, with AM interference suppression function ,the highest modulation frequency can reach 1.2MHZ, and the high-power output distortion is less than 0.1% Blue tooth 5.0 Input Supports instant setup with phones, tablets, and almost any other Bluetooth-enabled device. QCC3003 chip ensures your devices maintain a strong, stable connection up to 50 Ft away. Independent Treble & Bass Control You can try treble & bass control knob on the AMP module, to control your speakers. It is very simple and convenient to use,You can adjust the most comfortable volume that you want. 2.1 Amplifier with Subwoofer Audio Component Amplifiers The power of the adapted power supply should greater than the actual working power of the AMP to ensure the maximum output power, the higher the power supply voltage, the greater the output power. Best Gift for Audio Amplifier Enthusiast Best gift for Amplifier enthusiast Bring more fun to you and your friends. Notice: The smaller the impedance of the speaker, the greater the output power. we recommended to use a 4Ω speaker.