I am the guy who wrote the post to which Mphnkns referred. I do think the FS is a wee bit on the bright side and it may not be as smooth as other preamps, but I STILL think it is at top, top-notch performer and overall, maybe the best that I have ever heard. It took well over a year for me to find out how good the F.S. was. Let's just say that I find the F.S. unbelievably sensitive to tubes and I didn't do much tube rolling with it until I sent it back to Seattle for the 2004 upgrade. I am still trying to find a tube to cure some or all of my "complaints", but more about that later.
The beauty of the F.S. is in the transparence and the clarity and the absence of veils, haze or fuzziness- the electronic artifacts that you don't notice until they're gone. The incredibly low noise floor leaves others behind in the musical details which it reveals. The dynamics on this preamp are outrageous, but it never sounds false or artificial, as if they were there just to impress us. Female vocals are exceptional, delivered in a very intimate, up-front, close-miked way. It is not a subtle, refined presentation, but one which often borders on the aggressive, and I mean this in a good way. If you like female jazz vocals and you want a very high resolution CD which will show you what the F.S. can do, I recommend DeeDee Bridgewater's Dear Ella. Another extremely high resolution CD is Marian McPartland's 85 Candles. This one has vocals as well as plenty of instrumentals from stars of the jazz world past and present. Each CD ranges from the intimate to the aggressive, but the F.S. is never laid back on either CD and it delivers that you-are-there transparence.
Do I think the F.S. is a little hot? Yes, I do. It will jump at you (ring) on certain piano notes. Is it the smoothest linestage that I have ever heard? No, it is not. I hear a significant mid-bass peak despite the various tubes that I have tried (Siemens 6922, Telefunken 7308 and Siemens 7308). The upper mids are a little sharp. I wouldn't call it lean-sounding as the middle mids are quite smooth and the unit does deliver a lot of bass-maybe even a little too much. The very solid bass does nicely balance that slightly aggressive upper-mid area. So, although I wouldn't call it lean, I do hear what Mphnkns hears and I would call it a flaw, but it is one which I am willing to forgive, because of all the things which this unit does exceptionally well.
I would also point out that the rest of my system, perhaps save the Theta DAC, I would call it neutral although would call it laid back: Vandersteen 3A Sig speakers, Pass Aleph 4 Amp, Theta Generation Va Dac and Micromega T Drive transport. I usually cannot tolerate bright sound at all, so the fact that I find the F.S. a little on the bright side but I still love it says a lot for F.S. I have the F.S. Presence Deluxe Mk II 4.0 with two heavy duty power supplies. I also have a CAT SL-1 Ultimate which I still use from time-to-time. The cabling is JPS Superconductor (the original) from pre to power, Kimber 4TC shotgunned biwire on the speakers, Kimber PBJ from Dac to preamp and Ensemble Digiflux between transport and DAC. I use two Shunyata Sidewinder II power cords based on Emmanuel's recommendation.
So, I have embraced the FS, even though it is not perfect. It is right up to the limit of what I would tolerate in upper-midrange sharpness, but this is balanced by its unbelievable dynamics, clarity and transparence. I would try to work with this one rather than give up on it. The things that it does right are very hard to find in other products.
