Steps you can take:
Make sure your .WAV files are 16 bit and placed in the MUSICDAT folder on the USB stick. If your wav file isn't 16 bit you can load your audio file into Audacity and export as 16 bit if necessary.
Use the 3.5mm audio in on the back of PX560. Use a 3.5mm male to male to connect to your PC/audio device. This has the added benefit of having a separate audio volume controller on the back of the PX560. If you can't hear your audio file, make sure this rear volume knob is turned up.
I have my PX560 connected to my PC 3.5mm green audio output jack from the motherboard to a 1/4" left & right splitter for the (2) mono Line In (L, R) on the PX560. I use the PX560 as PC speakers (borrowing the keyboard is turned on) no problem.
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