Having played through most of the tube amps back in the day - Fender Bassman (w/100W conversion), Sunn Model T, and various SVT’s (mainly in rehearsal spaces / back lines), and most recently the TE Hexavalve - I decided quite some years ago that I prefer good tube based preamps and clean SS power amps. But, my tone goals have always been strongly in the direction of clean power. I do like the SVT for what it does in that respect BTW. But, I can get the same slam with considerably lighter, lower maintenance SS power amps.
For preamps, I’ve settled on one 3U rack with a Demeter VTBP-201 in it, and one 3U rack with and Alembic F1X and a DS5R in it for my Series I. Then I’ve got a 2U rack with a QSC PLX1804 in it. I settled on the 1804 after going through a PLX1602, a Carvin DCM2000L, and a Crest ProLite 3.0. Those are my modular rack choices. Good ones for my purposes. Here is one deployment from back when I had the Carvin, and before I broke the single rack up into modules.:
I’ve also got a Demeter VTBP-201 with the internal Minnie 800D power section. That is a ridiculously convenient way to get everything in one easily schlepped box.
Finally, the recent Ampless thing caused me to look at smaller DI options; and I settled on the Demeter Bass400J, which BTW has a ton of slam when used as a stand alone amp.
Not really looking for much else at this point, though I am tracking power sections with the ICEPower 1200 module as they are developed, and could be interested in one of those down the road. I know this is all more than needed; but, this is what happens when one accumulates good gear over time.