Upgrade from modified Bluesound Node 2i and linear power supply (LPS) ?

@audiotroy

you are entitled to your opinion but its just an opinion bro...

lots more to the spdif vs usb debate than asynchronous transfer and jitter... jitter is but one form of digital noise, important as it is to manage...

people own use a single dac at a time, and how that particular dac is engineered to receive what form and mode of digital feed - how clocking, galvanic isolation, aliasing etcetc determines what works best for that dac

i have been through some 50 dacs with a number of streamers using different connections since 2020... specifics matter, generalities don’t

here is a more complete explanation and discussion on the topic

https://benchmarkmedia.com/blogs/application_notes/13124137-the-unique-evils-of-digital-audio-and-how-to-defeat-them

USB vs Coax issues aside, The OP is curious as to the sonic benefits of moving up to a Lumin U1 mini. I also have a Node 2i with an outboard DAC and am considering my streamer upgrade options as well. I heard from a dealer that Lumin is going has discontinued the U1 Mini due to a chip shortage. So that means only stores with current stock or buying used are the only options. Also, a consideration should you need service and "that" chip is the issue. Maybe Lumin has a replacement unit in the works and maybe there is another digital streamer worth considering.

In all of my testing, I have always gotten an improvement in sound quality when I upgrade a switching power supply to a linear power supply -- as long as it's a good linear power supply.  The Sbooster has been communicated as a very good power supply.  A really excellent power supply in my testing is the Farad Super3 (but avoid the Synergistic Orange fuse upgrade).  Keces is another good one.

Thanks @audiotroy for the benchmark article. I read it from beginning to end and was impressed with the complete explanation of the quirks of audio signals. Now, if i could only see some of this information listed on amps. or even DAC's. (I have the Denafrips Pontus II after upgrading from the Ares II.   

@txp1, I really enjoyed the Chord Qutest before I got a TT2. It’s a great little DAC! When it comes to streaming music, I’m all in on Roon so I got a Roon Nucleus to stream Tidal and Qobuz. I have it powered by a 19v Sbooster LPS that definitely helped to improve sound quality. I use an iPad Pro and an iPhone 13 Pro Max as remote controllers.