The new player has a slightly tighter headphone jack, just plug it with pressure and it will be easier to plug in after few uses. F20 uses the MTP protocol and couldn't be properly recognized until the driver was installed, please make sure it's under USB mode, then connect it to computer to recognize it, and then use it as USB DAC, if you want to use drag and drop a file, set up at USB Mode. F20-Faq: 1. How to access the storage/SD card the player doesn't work with iTunes. It can be used as a computer decoding amp to improve the transmission of sound via Bluetooth 4.0 transmission, or as an amplifier to wirelessly connect with a smartphone. Aptx decoder technology for low latency transmission is used to create the Sense of Living Concert 2-Way Bluetooth Transmission F20 player can either work as a signal transmitter to connect to Bluetooth headphone, speaker or use as receiver amp - wireless connects to smartphones. It can work either as a transmitter or receiver to USB OTG port can achieve larger storage expansion to 128GB. The system can handle up to 14999 songs and 256GB of storage in a package.