How to connect Tidal to DAC wireless via iPad

Perhaps that could work. I have not seen a router that outputs via USB. Your router may have a USB port for another purpose. But a network cable out to the Node will work for sure.
In my experience the Node2i should be a nice improvement over your current setup. And you can always upgrade down the road.

Phill55, let us know how it goes when the Node2i arrives.
Enjoy!

The weak link you have now is using the iPad to push the signal to the DAC. Tablets and laptops are noisy and that noise gets into the signal. I agree that a streamer would be a big improvement. I went from sending Tidal etc from a laptop via USB to my DAC and when I moved to a streamer I was quite surprised at the improvement in sound. And then you need no wire attached to the Ipad. The streamer app on the tablet talks to the streamer via wifi for song album choices. But the signal is pulled into the streamer directly from the NET avoiding the Ipad electronics. If you can, it seems best to connect the streamer directly to your internet with a cat5 or better cable as opposed to via wifi.
You can try this out with a Node2i for not much $. You will be happy. And at some point you can upgrade the streamer as needed. But your  troubadour se III is a great DAC and I  would send the streamer to your DAC for sure.

Not all streamers output to USB. But most will out as optical Toslink. And if I am not mistaken, your DAC accepts Toslink as an input. A splitter or hub should be fine to the network cable to the streamer.