I've owned the following 6SN7 preamps:
- George Wright WLA12A
- Modwright LS-100
- Don Sachs Model 2
- LTA MZ2
- Atma-Sphere MP-3
The keeper is the MP-3, mainly because the synergy with my Atma-Sphere M-60 mono blocks can't be ignored. I bought mine used and liked it so much I sent it back to Ralph for the remote upgrade.
Surprisingly, the MZ2 is a very close second and I'm keeping it as my spare. Clean, fast, and the inner detail is fantastic.
The Wright, the Modwright, and the Don Sachs are all very, very good, and mostly just different flavors. You won't be disappointed with any of them.
I fully admit to being a 6SN7 fanboy.
David