Hey Ckorody. Nice post, haven't had the chance to read through it and digest it all but it should give the supratek crowd a little insight and direction into how they might find the right voice and synergy in their systems. The supratek preamps are a very high resolution, high gain preamplifier and choosing the right 6sn7 can have a profound effect in ones system. In my books: tonal balance is the main ingredient in any high resolution rig. Get the "tone thing" right and the other pieces in the puzzle become so much easier to put into perspective. There are so just many more flavours to be found in the 6sn7 family of dual triodes, far more diverse than any other tube type. Using the wrong spice can spoil a very fine meal. In my own experience, and as I mentioned in my previous post, the current crop of new 6sn7's are a far cry from a many of the better nos examples. That said: and not to complicate things even more here, there are also quite a few nos examples that are down right crappy in the supratek's as well. When employed in the Supratek, I am not a big fan of the Sylvania 6sn7 family nor the much sought after Rca redbase 5692. Go figure! the RCA 5692 is "far and away" the best of the best in my MFA Luminescence and the majority of nos Sylvania versions are superb in the Lumi as well. By contrast here, in the Supratek most of the sylvania examples can seem to be more extended up top but also tend to highlight this area in the mix. They can be a liabilty in many applications. When ones speaker system isn't tightly balanced "tone wise" in a given room, the utter clarity and resolution of the supratek will only serve as a magnifying glass, highlight and ultimately distort the perspective of the portrait. Braro: You have a very fine system to work with sir. The good thing here is the tonal balance aberration in your room is much simpler to to work with and far easier to get dialed in. The vast majority of rooms that many people have to deal with have the exact opposite effect, whereby too many of us have a big bump or boost in the upper bass/lower mid area. Usually a far more difficult exorcise to correct. Best of luck!