Bluetooth 5.1 Audio Amplifier Board, ZK-AS21 2.1CH 220W x 2 + 350W HiFi Amp Subwoofer Power Amp Mini Digital Audio Amp Module for Home Speakers(30-220W, 3-8Ohms), DC 16-38V, BT USB AUX Input

2.1 CH Subwoofer Audio Amplifier Board This AS-21 power amplifier is a 2.1 channel unit, enabling you to hook up 2 passive speakers and drive a subwoofer. It includes Treble and Bass controls, independent subwoofer volume adjustment knobs, and 20-200Hz subwoofer frequency tuning buttons, which is quite appealing to audiophiles. You can tweak the Treble and Bass controls to make the bass more impactful and the treble more distinct, adding greater depth to the sound. 220W*2 + 350W High Power Output This AS-21 audio amplifier delivers 220W*2 output power for the left and right channels and 350W output power for the subwoofer.

It can drive two high-power speakers (30-220W, 3-8 ohms) and one subwoofer (30-350W, 2-8 ohms), and the recommended power supply is DC16-38V/10A or higher.
Note: The higher the power supply voltage/current, the greater the output power; the lower the speaker resistance, the higher the output power. The power supply should be rated above the amplifier's actual working power. HIFI Audio Power Amplifier The ZK-AS21 power amplifier board features two built-in TPA3255 power amplifier chips. The TPA3255 is a high-performance class D amplifier chip that maintains ultra-low distortion across the entire audio frequency range while delivering high-definition sound quality. The wiring around the chip uses a window tin spraying design to boost output power. 6 x Low noise preamplifiers 5532 group enhance sound quality and volume, increasing gain. Multiple Audio Input Modes This mini amplifier receiver includes built-in Bluetooth 5.1, USB flash disk, USB sound card, and 3.5 mm AUX input. Bluetooth 5.1 mode offers faster transmission speed, lossless decoding, lower distortion rate, and a connection distance to audio equipment of 15m/49ft.
Note: When using AUX mode, please ensure the Bluetooth connection of this module is disconnected. With Protective Function This Bluetooth amp module is equipped with multiple protection mechanisms, including over-voltage protection, under-voltage protection, over-heat protection, and short-circuit protection, and comes with a case for added safety. Additionally, a long-life ultra-silent fan (locked rotor, no burning, no noise) is positioned above the audio chips for heat dissipation and protection of the Bluetooth amplifier board