In the last fifty years or so, I have had Tube class A, SS class A, SS class A/B, and several Hybrid amps and preamps. The preamps were all Class A’s and the Amps were all Class A/B.
Right now I have a Hegel H390, that’s a SS class A/B integrated amp. (The first integrated amp I’ve had in 35-40 years) and a PS Audio, BHK Signature preamp with PS Audio BHK 300 mono blocks. Both are hybrid. I have started tube rolling yet, but will probably do so.
Hegel is somewhat on the warm side and sounds really good with all kinds of music. It’s dead quiet. The highs are crisp without being sharp, the mids are very good, but I find tube amps excel with voices and the like much better and the Hegel has plenty of clean low end punch.
I’ve only had the PS Audio gear a couple of months. The Amps were bought used and came with 7308 input tubes. In my experience, 7308’s are really great sounding tubes, but are definitely brighter sounding than 6922’s or 6dj8’s. I’m going to replace the 7308’s with some 6922’s and see if the sound is more to my liking. So like the Hegel, this setup has a great bottom end a very good mid range and I’m going to tube roll until I het the sound I want. The input section on the preamp can use 12au7’s or the 6dj8 line of tubes, so there’s the place I will probably start with seeing as I have many 6dj8’s and 6922’s to choose from here.
One more thing, the Hegel is stable down to at least 2 ohms and probably lower.
All the best.