1?????? the onboard SJ2038 double BTL audio power chip, when thesupply voltage is 6V, in which THD is less than 10%, can provide 4Ω load 3.5 W output power or can offer 8 Ω load 2.2 W output power2?????? the main chip pin has led to external devices, convenientcontrol, onboard 2 Road 5.08 (mm) spacing of 2P terminals,respectively, the left and right channel output line 3??????onboard dial potentiometer, can adjust the volume of output size4??????working voltage: 2-6V 5?????? the board size: 36 (mm) x26(mm)