板子上电后默认蓝牙输入模式，在不接蓝牙的情况下，可以按一下主音量旋钮，切换到3.5 AUX输入。在播放音乐时，按主音量键也可以切换歌曲。

商品详情：

• 这是一款使用直流单电源12-24V供电，使用TI公司TPA3116D2高性能数字功放芯片为核心，一片做并联桥接低音声道功率放大输出，一 片做左右声道功率放大输出。可以支持100W(低音声道) + 50W(左声道) + 50W(右声道) 三声道输出。

• 支持 蓝牙音频接收，外接音源输入接口，带前级放大，低音分频处理；低音音量、低音频率、左右声道音量、高音、功能控制开关/总音量，5个调整电位器。

• 宽工作电压，省电型设计，效率高达90%以上。可使用性能良好的开关电源、笔记本电脑开关电源，还可以使用充电瓶，或车载电源等等 . . . 

• 板子是已焊接好测试好的成品板，按图接好喇叭箱，接上合适的电源，连接蓝牙音频设备播放，或正确接上音源输入，即可使用。
• 
• Tips: if you need Power Supply,Please Choose this :   24V 6A Amplifier Power Supply
           and if you need subwoofer speaker ,Please choose: 4OHM Subwoofer
   
  This is a support Bluetooth 5.0 audio receiver  Updated, with a pre-amplifier, Bass crossover  Processing. With bass, left and right channel volume adjustment, treble adjustment, the total volume potentiometer control 2.1 amplifier board.
   
  Use DC power supply: 12-24V Power Supply, Maximum support 50W (left channel) +50 W (right channel) +100 W (bass channel) three-channel output.
   
  Is the use of the United States TI company TPA3116D2 high-performance digital amplifier chip as the core, a parallel bridge subwoofer output, do a left and right channel output.
   
  Wide operating voltage, power-saving design, efficiency up to 90%. You can use good performance switching power supply, laptop switching power supply, you can also use the charging bottle, or car power supply and so on.
   
  Board is a good test of the finished product board is welded, according to figure connected to a good speaker, audio input or connect the Bluetooth audio device and connected to the power can be used.