Tube Rolling Woes

I recently took delivery of my first tube preamp. Schiit Freya+. It came with new production Tung Sol 6SN7GTBs. I'm running fully balanced from my source components right through to the power amp. My first impression was wow! What an improved soundstage with width and a 3D quality that I've read about. What surprised me is how quiet the system is. I had expected tubes to be noisy. But the Freya+ running with the new Tung Sols is dead quiet. The openness and air in the presentation is tremendous. However, from a voicing perspective, the top end is bright, and the mids and bass are very thin. I have about 75 hours on the system. Ive read and listened to almost every review on this model and no one has complained about the tonal balance. I left an email with Schiit just to make sure that I haven't done something wrong, but haven't heard back yet. 

I thought I'd experiment with some NOS and used vintage tubes. I've purchased from established, well respected vendors as well as folks with excellent feedback ratings on eBay. Of the 8 tubes I've purchased - claimed as tested matched quads (1) or pairs (2) - all but 2 have been either prohibitively noisy, or just didn't pass a clean signal. From my (admittedly small) sample, there has been no quality differences between the well-respected companies selling NOS tubes vs. people selling used stuff on eBay. The good tubes I've received were used tubes (RCA) sold by an eBay vendor. 

So I'm running out of patience. If I go with new production tubes that a vendor will have tested, matched and stand behind the quality, how do I know what to buy? Note that this is a $900 preamp. So, there are limits to what is practical in terms of price point. I can't justify spending more than $200 on replacement tubes. My concern is that even if I spend this kind of money, how do I know what the results will be? 

Any advice is appreciated.

Glen