the driver for 64bit is available now. you can try but need to enable unsigned driver mode
http://www.ibasso.com/download/DX50&DX90_WindowsOS_USB-DAC_Driver_Beta2.zip
(Post76 Android 手機版送出)
you welcome. although this is a beta version, and need to be run conditionally to accept unsigned driver, this is a good one to try. hope ibasso team will have further release and improvement on driver and firmware later on.
(Post76 Android 手機版送出)