@kds Great question. I have owned a few nice preamps in the last 10 years:
Pass Labs XP12 - very nice unit. It was quiet and was everything you’d expect from Pass
Aric Audio Motherlode - sound was okay, but as a single ended unit is was too noisy. I ditched it fairly quickly. I should have ordered it as balanced.
Don Sachs Model 2 - very nice preamp but only came as pseudo balanced at the time. A little noisy and Don worked with me to upgrade some internal parts that helped but not enough for me to have a long term relationship with. Although I did build the Pomelle wood case for it as a project challenge and it turned out nice for the buyer I sold it to.
Audio Research 5SE - I reached as high as I could go at the time up the chain and grabbed this used preamp from Will Vincent after a tremendous amount of research, both here and elsewhere. Extremely happy with the sound of this preamp and the damn thing is robust in design, super quiet in balanced mode, and just disappears from view because it has no quirks in its operation. The most musical preamp I have ever owned and here to stay.
In days long gone I have owned these other preamps. Some with stellar records and out of print now, so to speak:
Sim Audio Celeste P3
Cary SLP98P
Sonic Euphoria
Promethius TVC
Pass Labs X1
Audio Mirror T61
Bel Canto DAC3 Pre
Modwright LS36.5
Dodd battery
Response Audio Bella
Electrocompaniet EC4.5
Lyngdorf TDAI2200
Mapletree 4ASE
BAT VK3i
Auditioned a Rogue Athena
TRL Dude