Features:1. Adopting high-power digital power amplifier specific inductance, high current, low magnetic loss, low heat generation, using oxygen free copper wire to improve sound quality, and magnetic shielding mechanism to resist electromagnetic interference.2. Equipped with two TPA3221 chips, it supports 2.1 channel Bluetooth digital amplifier 100W+100W+200W high-power.3. Subwoofer expansion port, supporting the installation of 1602 and 3002.4. Multiple expansion ports, capable of connecting to microphone front stage board reverb input or output, convenient to use.5. Equipped with protection mechanism, input undervoltage, input anti reverse connection, overheating, overcurrent, and short circuit protection.Parameter:Product name: 2.1 channel BT amplifier board 100W+100W+200WProduct model: ZK-ST21Adapted power supply: The working voltage range is 12-30VDC, and it is recommended to use a DC power supply with a voltage of 24V-28V and a current of 10A or above.Maximum power: left or right channel—— 105W@30V , 4 Ω; 55W@30V , 8 Ω. Subwoofer—— 208W@30V 2 Ω; 105W@30V , 4 Ω. In short, the higher the voltage, the smaller the resistance, and the greater the output power.Adapted speakers: left and right channels, supporting speakers up to 3-8 Ω and 100W; The subwoofer supports speakers up to 2-8 Ω and 200W.BT chip: JieLi 5.1, transmission distance of 15 metersInput method: BT+AUX+USB drive+sound cardNumber of channels: 2.1, left channel+right channel+subwooferPower amplifier chip: Two TI original TPA3221Protection mechanism: Input undervoltage, input anti reverse connection, overheating, overcurrent, short circuit protection.Product size: 121x100x25mmPackage include: 

Type 1:1 x Amplifier board

Type 2:1 x Amplifier board

1 x Shell kit

Type 3:1 x Amplifier board external lead type

Attention:

1. Shipping does not include power or audio cables.2. Install external antenna (special scenario):2-1. The boards are all equipped with onboard antennas, with a normal distance of 10-15 meters. If they are installed in a metal shell (which will block the signal) or increase the Bluetooth distance (20-30 meters), external antennas will be used.2-2. Customers are required to purchase 2.4G antennas (antenna extension cables, antenna rods) on their own, and this product does not include external antennas.