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

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?

@maholl50, I also have a Cambridge 851N and a Luxman 505UXII. I am interested in finding out your preferred setup after your rotation exercise.  

Very happy with the Ifi Zen Stream. I’ve added it to my Squeezebox system, via the Logitech server software (LMS) into a Denafrips Ares II DAC. 

I had to go back and remind myself what i read back when i last looked at Pis for audio. I've had other pressing issues int he intervening 9 months.  From my perusal of the (sparse) documentation and the schematic it seems that they have separated the USB onto it sown controller and stopped loading the processor with some of the Ethernet duties- both of which will reduce some of the noise, to the degree that noise is proportional to workload.

As to the supply - if you mean the EXTERNAL supply, that’s where you need to spend some time or money. I built a well regulated and filtered , 3.5A linear supply. It ought to quiet things, and listening tests (vs the $7 standard issue cana-whatever unit) strongly supports this presumption. I can’t speak to mot commercial supplies, having never used them. Well, one exception - i had an ALLO DAC/Pi based bridge/Shanti to evaluate and study for a while and it was an impressive power supply for the price, I thought. It costs something under $200 and if i recall also supports both dirty and clean 5V outputs.

I also isolate the USB of the DAC following (if using the one i half-built) and the commercial ones has built in isolation, quite good from what i could see visually (an SMT transformer)