PS Audio Direct Stream DAC w/Roon Nucleus + vs. Auralic Vega G1

The most important part of auditioning DACs if at all possible,  do so without knowing which one you're listening to so you choose with your ears not your eyes or notion of if it costs more it must be better. Well designed DACs whether R2R discrete or chip and Delta Sigma are extremely hard to tell apart when evaluating blind. Some use filters or tubes etc.. in order to EQ the signal and that's fine it just makes more sense to apply the EQ at the speaker level. It's much easier to achieve the same effect for less money and easier to find a sound more pleasant to you. It would be interesting to know what speakers you're using to look at the FR, if it can be found, to see what's going on the the areas the ear is most sensitive to. Another way you can tell is if you have a calibrated mic and REW. Do a FR sweep leaving the mic in the same position switching between DACs. If the FR is the same or within .01%  then I doubt the DACs could be told apart. 

I can't comment on the Auralic you are considering or the Mytek you own, but I have the Directstream DAC/Roon Nucleus combination and am very pleased.  I've owned the DSD for more than two years so I have updated the software a couple of times and feel each update has been an improvement.

DACs are changing so fast now that an upgradable FPGA based DAC is a big plus in my opinion.

Understand that these improvements are rather subtle but they are discernible.  The updates don't change the overall sound of the DSD (neutral to maybe a bit warm, certainly not edgy) they typically eliminate noise or other artifacts.

I too have a PrimaLuna Amp (Dialogue Premium HP) and they are a good sounding match.  My preamp is also PrimaLuna so your results could be different there.

One last thought on the DSD.  I originally connected my Nucleus via USB (CuriousCable) and was very happy.  I also own the DirectStream Memory Player and was really happy with the sound with them connected via I2S.  So, I bought a devise that was recommended by a number of people on the PSAudio Blog to connect my Nucleus via I2S.  I use a Matrix X-SPDIF 2 that converts the USB to I2S.  It is a fantastic sound in my opinion.

I hope this is helpful.

So...I had a DSD for a few years and ran it with a Nucleus+.  It is very good but I cannot say that every software change is an improvement.  It is an excellent unit and given that software can be updated, it is less likely to become outdated.  Definitely less bright compared to the Mytek.  

An interesting alternative that is far more up-to-date is the Chord Hugo TT2 which is also an FPGA DAC.  It has balanced outputs and is awesome with an M-Scaler.  I would put the TT2 up against the DSD and my hunch is that today, especially when you consider the filters the TT2 has, it will come out ahead of the DSD.  You can tweak the sound to your liking.  The M-Scaler is a significant incremental cost but it takes the system to the next level.  

I know some disagree with that but that is the fun of this hobby.  I did sell my DSD when I became a Chord Dealer but am not at all disappointed with that decision and will never look back.  

I am a national Chord dealer and will take your Mytek (and any other equipment you have) on trade toward Chord products.  

scott (verdant) posts enough here that one can see his obvious knowledge and experience

i can also vouch for him as a vendor, i sourced my chord gear from him... excellent service, good pricing, and outstanding responsiveness

Thank you all for ongoing comments.  For the record, my speakers are Klipsch Cornwalls with a REL T7 sub running through a Velodyne SMS-1 management system

AC power runs through a AudioQuest Niagara 1200 and I have a Uptone Audio JS-2 driving DC power to Mytek and Nucleus.