Artg and Rayhall, The CAT Ultimate compared to the First Sound 4.0 is the same road I also traveled last year. I also wrote on at least one other thread about the CAT vs. the FS. And the impedance mismatch issue cropped up in a big way in my system with the CAT. The CAT had an extremely aggressive quality when paired with my Cary SLAM-100 amps (whose input sensitivity is .75 V). The First Sound is a much better electrical coupling with the Cary amps than the CAT was and the F.S. is by far the more natural and 'easy' pre-amp-although I would not say laid back.
Artg, Please update us on how the CAT integrates with your system over time. (I think we have both mentioned that the F.S./Berning 270 combo is a good one, too.)
Rayhall's experience with background noise in the CAT vs. the F.S. agrees with mine. The F.S. is much quieter. My system responded to the CAT exactly the opposite of Rayhall's experience. The CAT was anything but laid back. The CAT was bright to point of un-listenable. I know this is NOT the CAT sound, and I chalk it up to my power amps' sensitivity. The CAT's bass was simply astonishing--although overblown in my case.
The F.S. has detail galore but does not force it like the CAT did--in my system. The upper-mid band prominence that seems to be coming up in discussion associated with the F.S. turned out to be coming from PS audio outlets and the shelving I was using. Power cords, signal cabling, shelving, and tubes all matter a lot with the F.S.--maybe because of it's remarkable transparency and (theoretical) lack of coloration otherwise.
All other pre-amps I have worked with (Lamm LL2, AI M3A, CAT Ult, cj LS-16, ARC Ref 1 MkII) to some degree seem to hype the signal to get the music to come through above their respective, attendant noise floors. The F.S. seems to lay the signal bare by lowering the noise floor and then gets out of the way. The music takes on a less-processed quality---as Rayhall said so well.
