I've got no experience with the Zen BUT I think the following is what is going on.
What Roon's list of connections shows is a list of connections under Roon's control. That essentially means network connections (wifi or ethernet) and other connections such as USB/spdif/AES or analog outputs provided those other outputs are outputs available on the device running Roon Core. Roon can connect to your Devialet by wifi or ethernet so it shows those options. It does not show the Devialet as a USB option because the Devialet is not connected to the Roon Core device via USB. It is connected to the Zen via USB.
Try selecting the Zen as the Roon output option. Use the Devialet's remote to select USB as the active Devialet input. If you have to tell the Zen which of its outputs you wish to use then tell it to use the USB output the Devialet is connected to. It's up to the Zen to deal with its own output and the Devialet is not dealing with a Roon output, it's only seeing output from the Zen over USB. You need to tell the Devialet that you want to use its USB input just like you need to tell it whatever input you want it to use if you're selecting a disc player or an analog input. Roon simply does not see the Devialet's USB input because there is no network connection to the Devialet's USB input and if Roon can't see the input it will not appear in the list of outputs you can select in Roon.
You cannot select a Devialet input from the Roon list of connections if that Devialet input is not connected to the Roon Core in some way. There is no connection between the Roon Core and the Devialet USB input if the Roon Core is connected to the Zen and the Zen is connected to the Devialet via USB. In fact with this connection setup the Devialet does not even receive the signal the Zen receives. The Zen is receiving a signal in packets, not in real time. What the Zen does is to unpack those packets, assemble a PCM audio signal from them, and send that signal to the Devialet in real time. There is no signal connection between the Devialet and the Roon Core. Roon's output in this case is to the Zen, not to the Devialet. You can't select Zen outputs in the Roon list, only Roon outputs. That's why you aren't seeing the Devialet's USB input as one of the available outputs in the Roon list.
What Roon's list of connections shows is a list of connections under Roon's control. That essentially means network connections (wifi or ethernet) and other connections such as USB/spdif/AES or analog outputs provided those other outputs are outputs available on the device running Roon Core. Roon can connect to your Devialet by wifi or ethernet so it shows those options. It does not show the Devialet as a USB option because the Devialet is not connected to the Roon Core device via USB. It is connected to the Zen via USB.
Try selecting the Zen as the Roon output option. Use the Devialet's remote to select USB as the active Devialet input. If you have to tell the Zen which of its outputs you wish to use then tell it to use the USB output the Devialet is connected to. It's up to the Zen to deal with its own output and the Devialet is not dealing with a Roon output, it's only seeing output from the Zen over USB. You need to tell the Devialet that you want to use its USB input just like you need to tell it whatever input you want it to use if you're selecting a disc player or an analog input. Roon simply does not see the Devialet's USB input because there is no network connection to the Devialet's USB input and if Roon can't see the input it will not appear in the list of outputs you can select in Roon.
You cannot select a Devialet input from the Roon list of connections if that Devialet input is not connected to the Roon Core in some way. There is no connection between the Roon Core and the Devialet USB input if the Roon Core is connected to the Zen and the Zen is connected to the Devialet via USB. In fact with this connection setup the Devialet does not even receive the signal the Zen receives. The Zen is receiving a signal in packets, not in real time. What the Zen does is to unpack those packets, assemble a PCM audio signal from them, and send that signal to the Devialet in real time. There is no signal connection between the Devialet and the Roon Core. Roon's output in this case is to the Zen, not to the Devialet. You can't select Zen outputs in the Roon list, only Roon outputs. That's why you aren't seeing the Devialet's USB input as one of the available outputs in the Roon list.
Roon Nucleus+, Devilalet Expert 140 Pro CI, Focal Sopra 2, PS Audio P12, Keces P8 LPS, Uptone Audio EtherREGEN with optical fibre link to my router, Shunyata Alpha NR and Sigma NR power cables, Shunyata Sigma ethernet cables, Shunyata Alpha V2 speaker cables, Grand Prix Audio Monaco rack, RealTRAPS acoustic treatment.
Brisbane, Qld, Australia
