Sony introduces a new headphone with a build-in DAC:
I am wondering if the USB DAC input/output is restricted to 40.000Khz
Wide frequency response for a full range of sound
The wide frequency range—spanning 3 Hz to 100 kHz—is designed for today’s broad variety of music styles. The 3 Hz low end of the frequency range offers more than enough latitude for even the deepest sub-bass notes. At the 100 kHz high end, enjoy vocal melodies and subtle audio harmonics and tonality, giving your music more life and realism.