This is a great success to apply volumio with 9038pro. I implemented all my knowledge to make it for home or car use with auto safe shutdown, output delay leech and it spent 3 months to finish. It used 12v supply and convert 5v, 9v and 18v. For the control part I used wemos mini to control switch on off when it detects power on. Moreover, because wifi is sucked if using ssd, I added a 4g wifi routIer board to connect pi4 to LAN port on the board and disabled pi4 wifi so that I can connect internet radio and also my mobile can access internet.
For the 9038pro, I used tps7a4700 and tps7a3301 also for powering opa838 op amps. All audio note cap, 100mhz ocxo, creating best sound reproducing. It supports both RCA and balanced output. But for this board the balanced output hasn’t passed the LPF op amps. The USB interface I used unknown China brand with supports up to pcm1536 and dsd1024.
The 1st version had been taken by my friend instantly and this is the 2nd version with dsi monitor, of cause the case is modified by factory. All ports are standardized in xlr format for easier implementation and flexibilities.