I use the D.BOB to convert DSD from my OPPO (a real cheap one). The DSD goes into my Schitt Yggi+ DAC via SPDIF. It sounds amazing.
GeerFab Audio D.BOB digital breakout box | Stereophile.com
The Yggi DAC is way better than what is in the OPPO. The Venus DAC is better than the OPPOs. However, I am not sure if the Venus will work with the D.BOB. It works with my Benchmark DAC3B and the Yggi.
I am not sure if you can take HDMI and get the pure DSD out of I2S.