Working nicely. It has ac1082 ic on it, so this mean has lot secret function in the ic. Usb soundcard, cardreader, different functioning pushbutton ( EQ, Vol + -, ) . don't have "strong" virtual ground, use a pair of few hundred uF condenser to direct headphone out. Littlebit noisy the output, but not horrible. If you are creative, may you create a nice (portable) DAC/DAP.
Added some wire for few inbuilt stuff. Removed the amplifier IC, replaced and wired with an eprom. Working. Now remember the last played song, volume, and EQ setting. boot to soundcard mode is only w/o the sdcard, after booted, it appear the removable surface.
40 tuday Türkiye