For those who wish to hear possibly the purest unprocessed sound of the M2 walkman.
You can try this mode, This mode has absolutely the least Sony sound processing feeling especially with direct source mode ON and high res streaming off:
With Walkman screen turned on, hold down hardware power button for two seconds, a menu will popup. Tap on restart. While the Walkman is restarting, hold down on the hardware VOL Down button. Once it boots up, you will see a big safe mode word on the bottom left corner, that’s when you can release the volume down button.
To exit safe mode and return to normal Sony sound processing, just restart the M2 Walkman.
Do note this safe mode mode will not work with streaming apps or other music player apps. Only Walkman music app works.
Dad Remastering also sounds even more pure/analog/smooth in this mode.