EverSolo DMP-A8 with Denafrips Pontus 15th, both have i2S

@jastralfu so to get a definitive answer to the question about clocking, I asked Hans Beekhuyzen on his eponymous YouTube channel. His response is below.

"All ethernet devices are asynchronous and thus have no clock that is related to audio. So the streamer has to clock the incoming packets of data into an I²S stream. That will clock the internal DAC. If the connection to an external DAC is over USB, being asynchronous, the DAC has to clock the incoming packets of bits. If the connection is over AES/EBU, SPDIF, TOSlink or I²S, the streamer will clock the signal. Except when with I²S the DAC can be set to the internal clock."

I have a Gustard R26 and it can be set to use an external clock that clocks the I2S input. This is not common but not rare. I have heard somewhere that Denafrips DACs are also set to clock I2S inputs internally when slaved to their Denafrips clocks like the Aether.

Hope this clarifies things a bit, just wish digital gear manufacturers would helpfully clarify this issue in their manuals.

I'm no electrical or sound engineer but consider:

    This visual comparison to Denefrips DDC clocks is interesting.   https://www.youtube.com/watch?v=3SbK2kxg7X0  
     Alvin calls both Hermes and Gia clocks Oven Controlled, though I wonder if the Hermes at half the size are actually Temp controlled.  As a lexicon aside, all the Denifrips clocks are FEMTO clocks,  precision crystal, TXCO, or OCXO.
   USB, SPDIF, COAX, and the Ethernet are usually Asynchronous protocols with embedded multi-clock streaming (sorry Hans)...a DAC connected via these uses the embedded source clock in the signal at first... but the Denifrips DACs use a FPGA chip to buffer and re-clock (using the Source(sync) or DAC(async) clock) all incoming signals before R2R digital conversion...including I2s, which is Synchronous (with 2 clock channels, word and global, and the data channel).  With a synchronous connection the Source clock is used...the "source" may be the Digital transport, Streamer, or DDC.

   My ears clearly prefer the I2s sound (lower noise floor) from OPPO 83-HDMI breakout box-Pontus II 12th-Holo Bliss KTE-Susvara HPs,  though I believe it's the OPPO clock being used. Also USB is not far behind.  Probably a Hermes in the chain would clock and sound better.

A followup....I'm fluxomed, cause I use the OPPO HDMI output to the breakout box to get I2s into the Pontus so as to enjoy the DSD DAC in the Pontus to hear SACDs with a better DAC than the OPPO...depending on the recording it can be the Best Sound on the headphones. 
   The Hermes has no I2s input so I can't use its better clock (via I2s output) AND enjoy better DSD sound.  Need a DAC with two I2s inputs or a fancy Master Clock setup.  Or just forget all this OCD clock tech stuff...lol and enjoy the Music!