【What chip does this power amplifier board use? ] This power amplifier board adopts two TPA3116D2 chips, wide voltage input DC: 12-24V, and the output power amplifier peak value can reach 50W*2+100W (PMPO).【How many input modes？】 If you are inserting USB or AUX while playing music in Bluetooth mode, the power amplifier board will automatically switch to AUX or USB.Memory mechanism: if you used Bluetooth mode last time, this time before the power on of the power amplifier board, whether you plug in AUX or USB, the power on of the power amplifier board is still in Bluetooth mode. If you used AUX mode or USB mode last time, the power amplifier board will be in AUX or USB mode this time.【Treble and Bass Controls！】 If you are tired of the inherent treble and bass, why not try the treble and bass control knobs! No matter what, you can always create the sound you like.【Additional Features！】In order to explore the maximum potential of this power amplifier board, we have developed an APP for this power amplifier board. You can adjust the sound effect of the power amplifier board through the APP, set the Bluetooth name and password of the power amplifier board, and even set whether a prompt sound is required, etc.【7 * 24 Hours After-sales Service！】Paying Attention To Customer Experience And Satisfying Customers Is Our Service Tenet. If You Have Any Questions About The Product, or The Product Has Quality Problems, Please Contact Us At Any Time, We Will Give You A 100% Satisfactory Answer.