Amp pairing for Sierra 2 bookshelves and Vtf-1 Mk2


I've been running this pair for a while off of my Bifrost Uber and Yamaha R-S500. I've caught the upgrade bug as it seems that my amp is pretty lo-fi compared to the rest of my setup and I would like to get the most out of my RAAL tweeters. I have seen some pretty good deals on a few amps: Rega Brio-R, an Outlaw rr2125, a Rega Mira 3, and a NAD C352. My budget is $500-600 shipped and I am unable to audition amps. I have no issues routing my speakers through my subwoofer so not having a subwoofer output will not be a big deal. I appreciate any help I can get and thank you for your responses!:):):)

Jemidy70
jemidy75
Hmm well that's worrisome as I just ordered a Virtue One.3 but for the sake of future upgrades I listen to a wide variety of music. Hip-Hop, Krautrock, Jazz, Electronic, Folk, Punk, Prog-Rock, among other things. I've heard the ONE.3 is comparable to the Nuforce IA 7 V2 so if you've heard that you have an idea of what my system will sound like. I would say that I love mids and highs so the treble news is saddening.
Fear not Jemidy

I also had the Virtue Sensation M901 which is the bigger brother of the One amps.I recall the sound as being smooth, and tonally rich. The amp boogied and had tighter bass than the Nad I had before it. The only thing I didn't like was the sound stage was some what narrowed, but I later found out that was probably due to the older tubes I had installed in the Dodd tube buffer.
Good to hear any recommendations as far as preamps go in the >$500 range? I was going to go with the Schiit SYS passive pre but with your experience you might know something better!