Dear info2rdw,
You have found yourself in a common quandary, I can relate. I have not tried Vivaldi with vs. without preamp, but I have done that experiment many times in the past with other gear and always preferred having a pre in the chain. Opinions on this run the gamut, of course . I am using Ayre Twenty Series gear (not my very favorite but I had a nice opportunity) which is pretty neutral in terms of timbral coloration. With the Berkeley Ref DAC, removing the preamp was slightly more detailed but somehow lacked the full weight and body I heard with pre. As value goes, the preamp gives the least bang for buck of everything on the rack, but now that I have it, it’s going nowhere. Imgoodwithtools, who posted in this thread, drew the opposite conclusion, using the same DAC and amps that I was running! So what gives? I have not heard the Soulution products but I gather they are pretty special and you might miss it if it goes. BTW, I looked at your related posts and I certainly agree with folkfreak, cables and cords will make a bigger difference than pre vs. no pre.
I have a dCS Network Bridge and two Transparent XL digital cables arriving tomorrow and I’m looking forward to hearing the Vivaldi for the first time with proper server implementation. I am also switching from Aurender to Roon, using a Nucleus. I will probably add the clock in a year or so, when the piggybank gets bloated again. Once I’m broken in, I would be happy to repeat the experiment for you, but I’m not sure that would be worth any more than my opinion about anything else. I also noted the sources you are considering. To my ear Roon off a noisy laptop sounds better than the Aurender N10. Perhaps the W20 w/ Vivaldi and master clock would be different?
I have heard a Vivaldi vs. Rossini shootout (DAC only) and it was no contest. Since you (like me and many others) seem to have a generous budget but not an unlimited one, perhaps you might consider a Vivaldi DAC now and Transport later? I don’t have any SACDs but I am curious to know what the pending Rossini transport will offer. If that device is compatible with Vivaldi, and deemed worthy, that might be an option for both of us.
Rambling aside, I suppose if I were to just answer your question, I would much prefer to have a Vivaldi without my preamp than Rossini with? Good luck! David