iFi ZEN Stream

[hardcore]

I still wonder if adding some DDC between the Zen and the Devialet can bring an improvement. 

Although based on things I have tried in the past, sound quality with the Mutec MC3+USB is very similar to that with Ethernet CI Board. The Zen Stream direct to the Devialet also sounds very similar to Ethernet to the CI board. So I suspect adding an MC3+USB in the chain with the Zen will not offer much. Indeed, if we go with the GoldenSound measurements, adding the Mutec in the chain might actually be very slightly detrimental to the Zen's performance.

I have similar findings. The 1000 Pro's CI streamer sounds very good. It was difficult to improve the sound with my Singxer SU-6 alone. Special care had to be taken for the USB cable to the DDC, and the output AES / SPDIF cable to the Devialet.

In my case I felt the sound via DDC was better only after I switched to the abovementioned optical USB cable, and for the AES/SPDIF cable to the Devialet, I actually find Toslink to have a great overall sound, and am now using an AES XLR cable with the ground lifted. In my system's USB chain I've gone the route of trying to achieve 'maximum galvanic isolation' between devices.