Even though they can both be used to play music, Ethernet and USB don’t do the same job.
An Ethernet connection does not output decoded audio directly to a DAC. It sends music files or streams to a built-in music player inside the streaming DAC. That internal player then reads the file, decodes it, processes it (usually into I2S), and feeds its own internal DAC to be finally converted into analogue.
In other words, when you use Ethernet from the Innuos, you are using the external Streamer as both music player and converter, using its internal streamer and software to handle most of the work. The Innuos has a reduced role functioning as server only.
USB is different. A USB connection sends already-decoded audio data straight to the DAC. The Innuos becomes the music player, with Sense app in control. It lives outside the DAC, and the DAC’s internal streamer is bypassed entirely. This means USB is not just another “input” that is equivalent to Ethernet on the streaming DAC — it changes where the music is processed and how much digital work happens inside the DAC.
Why does this matter? Because digital processing creates electrical noise and timing errors, affecting sound quality. Using a high-quality external player and dedicated interfaces allows that work to happen outside the DAC, in purpose-built hardware with better power, clocking, and isolation. The result is a cleaner signal, lower noise, and a more natural, realistic listening experience.
In short:
Ethernet delivers music files to a separate player.
USB delivers music directly to the DAC.
Which one is best for you depends on the specifics of your system. There will be a difference in sound, but crucially there would also be a differnece in how you use the system with regards to the control app.