2.1 channel Bluetooth amplifier board 200W Class D with USB, APP control, and MIC KTV function.

This 2.1 channel Bluetooth amplifier board is a powerful Class D digital amplifier designed for speaker modification, home theater systems, and car audio projects. The total power of 200W (2×50W stereo + 100W subwoofer channel) provides powerful and clear sound. This device is suitable for DIY enthusiasts who want to create a high-quality Hi-Fi audio system at home or in the car.

2.1 Channel Bluetooth Amplifier Board - Key Features

• Powerful 2.1 channel sound — 50W×2 stereo channels plus a 100W subwoofer channel provide powerful, balanced, and deep sound reproduction in any environment.
• Five Independent Controls — Individually control the master volume, bass and treble frequencies, subwoofer volume, and crossover frequency (20–200Hz).
• Three Audio Input Methods — Bluetooth 5.1, AUX wired connection, and USB memory support allow for convenient music playback from any source.
• Smart App Control — A wireless mobile phone app allows you to turn the device on/off, change the audio source, and adjust the EQ without touching the board.
• KTV Expansion Ports — Two microphone echo input and output ports allow you to connect an additional echo module for a home karaoke system.
• Advanced Protection and Cooling — An enhanced heatsink and protection against overvoltage, short circuit, and overheating ensure stable operation for extended use.

Technical specifications

• Brand: Sienwiny
• Model: YS-TB21H
• Channel Mode: 2.1 channels (2×full-range stereo + independent subwoofer output)
• Output Power: left/right channel 50W×2; subwoofer channel 100W; total power 200W
• Operating Voltage: DC 12V–24V wide range input
• Control Knobs: 5 independent precision encoders — master volume / left-right bass / left-right treble / subwoofer volume / subwoofer crossover frequency (adjustable 20–200Hz)
• Audio Technology: Hi-Fi low-distortion circuit, fully shielded power inductive coil, high-capacity low-ESR filter capacitors
• Protection Circuit: multi-level protection — against overvoltage, undervoltage, overheating, short circuit, and DC offset
• Supported Speaker Impedance: 4Ω–8Ω (full-range and passive subwoofer speakers)
• Compatible Usage Scenarios: DIY desktop Hi-Fi speakers, home theater system, car subwoofer modification, store background music, mini KTV audio system modification
• Audio Input Methods (YS-TB21H): Bluetooth 5.1 + AUX wired connection + USB memory local music playback (3 input modes)
• App Control: remote on/off, one-touch source switching, visual real-time EQ adjustment, wireless parameter setting
• KTV Expansion Ports: two independent microphone preamplifier echo input and output ports
• Cooling: Enhanced, thickened integrated radiator for stable temperature during prolonged use.
• Standard Accessories: 1 x adjustment screwdriver + 1 x DC power terminal adapter.
• DC power input: External DC power supply terminal.
• AUX audio input: 3.5mm analog audio signal connector.
• Left channel output: Connect the left full-range speaker.
• Right channel output: Connect the right full-range speaker.
• Subwoofer output: Connect the passive subwoofer.
• USB audio input (YS-TB21H only): USB memory music playback port.
• MIC echo input port (YS-TB21H only): Microphone signal input for karaoke.
• MIC echo output port (YS-TB21H only): Expansion port for external echo module.
• Package Contents: 1 x Sienwiny YS-TB21H 2.1CH amplifier board, 1 x adjustment screwdriver, 1 x DC power terminal adapter.

Who is it suitable for and how to use it?

The 2.1 channel Bluetooth amplifier board is perfect for DIY audio enthusiasts creating their own speakers, as well as for home theater, car audio, or store background music systems. Use a DC 12-24V power supply that meets the power requirements, and connect only passive 4-8Ω speakers. Active speakers are not supported, and the subwoofer output is only for passive subwoofers.

Buyer questions

Question: What is the difference between the YS-TB21H and the standard version YS-TB21?
The YS-TB21H has additional USB playback function, mobile app control, and a dual microphone echo expansion port for home karaoke, which are not available in the standard version.

Question: What power voltage should be used?
A DC 12V-24V voltage is required, depending on the power requirements. Using an excessive voltage may damage the board, so it is important to select the power supply carefully.

Question: Can active speakers be connected?
No, the amplifier only supports passive speakers with a 4-8Ω impedance. Active speakers with built-in amplifiers are not compatible with this board and may cause malfunctions.

The 2.1 channel Bluetooth amplifier board is a reliable and versatile solution for DIY audio projects, home theater, or car audio systems, offering powerful sound and flexible control.

Sources: Audio power amplifier | TopSmart store