Asynchronous USB vs. SPDIF with regard to DAC upgrade

That makes sense @rossb 

a computer used as a streamer via USB is never an optimized streaming solution. Especially one that doubles as Roon Core. What your Matrix is doing is reclocking the USB signal as part of converting it to SPDIF. That will improve jitter levels going into your DAC and the final result is better sonics. 

With a dedicated streamer such as U2 Mini you get an optimized USB output that’s prioritized for audio. It’s never the case with a computer. 

It’s easy for the OP to test this. Get a USB cable that’s comparable in quality to the SPDIF that he’s using currently and compare it within his current Lumin and Weiss 204 setup. 

The 2 contenders for a dac upgrade are the Weiss 501MKII and the Berkely Dac Alpha Series 3. The are both priced within $1000.00 of each other with the Weiss being more expensive. My thoughts are that the Weiss 501MK II has a built in headphone amplifier, a preamplifier and room correction capabilities. I have the Weiss 204 which has no bells and whistles and only gives me the sound. Yes I did a $1000.00 Modwright Linear Power Supply. To my way of thinking this makes the Berkely Alpha Series 3 Dac a better value if every thing else is equal. A portion of the asking price for the Weiss must include the extras that Weiss offers. I do not think I can audition both at the same time doing an A-B comparison. At this price range would like to get this right. I would buy the Berkely without the USB box which costs an additional $2500.00, and would use it through SPDIF or AES/EBU, balanced.  Am I thinking about this in a reasonable manner?  Thank you. 

I will second @audphile1 advice to consider a DAC that supports Ethernet and serves as an endpoint. I recently picked up a Bricasti M3 to pair with my Innuos Zenith streamer using USB. On a whim I bought an Antipodes CX server at a good price and set it up as a Roon server and ran a direct Ethernet cable to the M3. There was no going back. I did all sorts of comparisons with the Zenith and USB, even tossing in a DDC so I could compare with SPDIF via AES. 

Now my thoughts are on upgrading the Bricasti, or trying the Meitner or Tambaqui, but I don’t think I will be going back to USB or SPDIF. It looks like the Weiss 501 supports this, I would give it a try, and don’t overlook a server upgrade as well. 

There are dealers that would allow a home audition if you’re buying new. 
Berkeley’s lack of USB, no network card makes it a tough sell. Being s straight DAC only it will be much harder to resell on a used market and you will most likely take a significant hit. 
I would suggest finding a dealer that can allow you to audition and compare several DACs in your system or buy with return policy. 

@kjl1065 here’s another valuable option in your price range

https://tmraudio.com/fresh-arrivals/dcs-bartok-apex-dac-d-a-converter-1-13/