USB-tier manufacturers with a stable performance VIA VT1630.
High resolution, under a wide range of frequency support 24BIT 44.1K-96k.
Android 4.2.2 system can support OTG mode (need native system).
Support for Apple phone, tablet OTG mode, etc.
DAC part is fine CS8416 + CS4398 LPF output using OPA.
Note: The volume adjustment knob does not function on the RCA interface, RCA interface is the red, white output interface.