The most dynamic preamp which I have heard is the First Sound Presence Deluxe. However, in order to hear it at it's most dynamic your choice of tubes is important. The Siemens 6922, in my opinion, brings out the dynamics the most. A little less dynamic, but also less ragged in this pre is the Siemens 7308, which makes this a world-class linestage. The F.S. has a solid bass, but, in my system, not extremely deep and, in my opinion, lacks the iron-fisted grip that you talk about. However, it does have an extremely transparent midrange which makes female vocal and horn listening very exciting and even sometines breathtaking. In the right system, with the right recordings, the vocalist can appear as if she is in your room singing to you. Great soundstage and separation of instruments. Unlike the CAT described below, no sweetness here, but still, due to the transparence, a very engaging sound.
Slightly less dynamic, but with deeper and more iron-fisted bass is the CAT SL-1 Ultimate. I think if you like the rock-solid, powerful deep bass, you should listen to a CAT. From the lower mid on up, the sound is sweet, smooth and musical, rather than hiper-detailed. The music is all there, but not in the super-transparent manner that the First Sound presents. Great musicality, lush but not syrupy sound, wide soundstage, but doesn't have the near-pinpoint imaging of the F.S. The imaging here is more diffuse than the F.S., but as an integrated whole, this unit is also exceptional.
I have not heard the Wytech or the Placette, but have heard the stock Aesthetix Callisto Mk I. I thought this unit in the system in which I auditioned it specifically to be lacking in dynamics. Just my opinion.
I do own both the F.S. Presence Deluxe Mk II 4.0 and the CAT SL-1 Ultimate Mk I.
