I agree with all the above (re. external sources). I was able to borrow a Devialet 250 Pro with a streamer board and compare it to my D 250 expert with external streaming through AES/EBU using SOtM SMS-200 ultra and the Mutec MC3+ USB at the time which is now replaced by the Denafrips Gaia. As a result, I didn't upgrade to the pro but got a second D 250 to make it D800. It's a shame that when Devialet decided to build to the streaming board, they didn't opt for an OCXO clock.
I use an Etherregen switch (clocked externally) and it improved the sound quality with the SOtM streamer too.
I use an Etherregen switch (clocked externally) and it improved the sound quality with the SOtM streamer too.