1. Pixel XL
2. stock ROM, Android 7.1.1
3. According to the blog by Qualcomm https://www.qualcomm.com/news/snapdragon/2016/10/04/pixel-phones-made-google-powered-snapdragon-821, support for 192kHz/24bit audio is brought by Snapdragon to Pixel XL:
The power of the Snapdragon 821 processor extends into the Pixel smartphones’ audio capabilities through stunning Hi-Fi audio playback. The phone features the Qualcomm Aqstic audio codec, designed to deliver high dynamic range and high-resolution playback up to 192kHz/24bit to create a remarkable audio experience designed to match the demands of the modern audiophile.
Also I tested with USB Audio Player PRO from Google Play, it is able to output 192kHz/24bit audio on my phone.
Thanks!
