What are you using as a streamer? Constructive feedback please.

A vote for LMS (Logitech Music Server) here. It integrates very well with Qobuz. I've got a collection of FLAC's on my Raspberry PI server also. I have cheap Pi's in two other rooms that feed other systems with good dacs. Interestingly, when listening on my PC, I can't tell the difference between direct Qobuz and playing through the streamer using an excellent dac/headphone amp with either my Beyer DT880 or Monolith Planars. The only downside that I can see is that it's not plug and play......

One of the big improvements of the Raspberry PI 4 was to separate the USB bus from the ethernet bus. Why?... Because of the noise of the shared bus.

Yep!  And its a big improvement.

On the 3 you had to build a HAT

Both USB and ethernet are connected to the same internal AMBA bus in the internal pi 4 processor. They didn't separate out things the processor in the pi 3 and 3b did not have integrated ethernet. The new processor has integrated ethernet and only requires an external phy. The old one didn't have ethernet so they use the chip that provided USB and ethernet together. Due to the reduced performance of the original USB I/F from the processor they could only do 300 mbps on the ethernet (3b+), 100mbps(3b). It had absolutely nothing to do with noise but about data transfer bottlenecks. In terms of noise they both use the same power supply which is where most of the noise will come from.

I think you’ll like the e.One Stream, I certainly like mine. The Seek app isn’t bad, but I much prefer the ui of Roon, and the Stream is a Roon endpoint and setup is a breeze. I’m pairing mine with a W4S DAC and couldn’t be happier with the sound. Guessing you’ll have similar results with your DAC 2.7. Good luck and let us know how it works out for you.

Sure all USB sounds alike. If you can’t hear it then it must be true.

While Raspberry Pi 3 Model B+ added Gigabit Ethernet connectivity, throughput on Raspberry Pi 4 is free from the single shared USB 2.0 channel to the SoC

The USB host controller is connected directly to the SoC via a PCIe bus. The Ethernet Controller is built directly in to the SoC.

What are the three laws again and do forums count?