Problem with Qutest DAC

Audirvana (Studio nor 3.5) does not recognize coaxial (RCA) connection of my Chord Quest DAC, which is connected to my iFi ZEN Stream. It finds only USB connection*
Here is the schema of my connections:
iFi Zen stream output to Qutest input by coaxial-RCA, Qutest analog output to my ampli by RCA cables
With ROON this works very well !!!

Sorry my problem is solved. In fact I had to change manually the output device of playback option in my streamer, to SPDIF everytime I change the input of my DAC SPDIF/USB
With Roon, it was done automatically.
It seems that iFi streamer is going to release a firmware with this function.