Asynchronous USB vs. SPDIF with regard to DAC upgrade

Hi @kjl1065 yes this gets confusing doesn't it?  You are spot in in that with USB, the DAC controls the clock, and with other connections, the streamer controls the clock.  So it is really dependent on your DAC and streamer.  I have two systems, and one (Master Fidelity  Nadac C and D wants USB, while my Grimm MU1 upsamples nicely for my Tambaqui and uses AES for best result.  I did learn this also: some DACs need the power which is inherent in USB and some do not.  My Aries G2.2 allows me to turn off the power in the USB, thus reducing noise.  I guess I would want my streamer to support both, and then determine if you like the sound of a particular DAC which to use.  So that would be a question to Berkely. 

While not our question, in that pre range have you considered the Tambaqui?  I find it exceptional, especially with the Grimm MU1 streaming to it.  I also like that the Grimm MU1 runs Roon core at the same time.  I also have listened to the MU2, which is streamer and DAC, and it is very good.  Since it is internal streamer and DAC, it negates your question entirely!

It’s honestly a little complicated.  It’s true that USB Asynhcoronous is theoretically the best jitter performance, but it’s also true the Berkley Alpha is a very good sounding DAC.  I'm not sure how they deal with signals > 192kHz or 32 bits, and that may be the big limitation of S/PDIF, which USB 2.0 overcomes. 

DAC’s do very well with the "normal" jitter of a modern streamer.  The PLL circuit and FIFO buffer will adapt, and so long as the streamer’s clock doesn’t suffer from truly terrible jitter performance you should be OK. 

An alternative however may be the Bricasti. 

The overriding factor should be which DAC will best give you the sound characteristics and improvements you’re looking for. 

Your Lumin U2 Mini can be eliminated as I mentioned in your other thread. It’s a good streamer but it doesn’t beat network cards in Bricasti or Meitner. If you’re a Roon user, just get the highest quality DAC with built in network card. Examples - Bricasti M21, Meitner MA3i, Mola Mola Tambaqui.
I eliminated Aurender N200 with Audience Studio One USB cable, with Meitner MA3i. I compared the crap out of it with and without Aurender, using native conductor and using roon. I preferred the Meitner as Roon end point as it sounded better to me. Sold the N200. I can tell you that the N200 is noticeably better than Lumin U1 Mini and therefore it’s also better than the U2 Mini as I’ve not heard of U2 Mini being an upgrade over the original. 
Keep your options open. 

Makes sense @audphile1 .  But, I have direct experience with MM Tambaqui first using its internal Roon Bridge and then with the Auralic Aries G2.1 and 2.2. and Grimm MU1

The sound was more lifelike and palpable with the streamer.  The G2.1 was annoyingly unstable, the 2.2 rock solid.  But the Grimm upsamples everything to 192 and sounds great using AES.  Better than no upsampling and USB to my Tambaqui.  So the Grimm MU1 and the Tambaqui  are a great combo, using AES, and it just shows how equipment can be so specific.