After some struggling, a XMOS XU208 + ESS9018 DAC module as the first step.
The module contains all the power management circuit, TCXO, such that it works with a single 5V (USB power), and the following control
1) BT, analog, USB input selectable
2) APPLE/Android input selectable
3) USB and two buttons ESS bit perfect vol. control
4) USB and button Mute control
There is external relay control pin from XMOS to allow selectable output between ESS DAC output and an analog source
The volume and mute control is UAC 2.0 compatible, or through buttons connected to XMOS
The XMOS software is under development, hopefully to update you within this month.
I was wondering if anyone would be interested to purchase this module if it has a price tag of USD40 + shipping?