best preamps

Still in use:

onkyo P-308
B&K pro 10 mc (newer model)

used but newish : McCormack LD-2
 
new under 5 hours- Sanders preamp. 

All have their merits. 

This the best pre I’ve ever heard:

https://hometheaterreview.com/linear-tube-audio-microzotl-preamplifier/

Lightspeed attenuator mais sûrement pas assez cher... 

I use to own the 17ls2 regret selling it!

Lancelock how much better is microzotl compared to the MZ2? In%.

Best I have heard . Gryphon Mirage and Ypsilon ...forget pre model but Phono stage is Ypsilon Silver ....$80 000. For my limited budget Yamaha C2a refurbished Yamaha CX 1 and Sony E90ES - units I use regularly. Luxman C03 is decent too. So much to choose from..

I agree with Elizabeth, the best preamp is a free preamp. 

Best preamps i'v heard Pass XP20, Accuphase C280V, C290,
Z systems RDP-1 digital digital preamp from the late 90s.  You do need a dac for the Z Systems RP-1 preamp to work.  TRL Dude tube preamp, Mcintosh C2300 tube preamp. Sony TA ER1 preamp, 

I do like my Teo Audio Liquid Pre passive. No AC grunge to dirty up the sound.