What is your favorite tube for a preamplifier ?

I have used many the 6sn7 or 6sl7 are more bloomy not quite as accurate though the build of the preamp and coupling capacitors have a lot to say about the final sound also I use the 6h30 supertube in the special dD grade and I get plenty of soundstage quickness and musicality .I have the new Lector 0ohm preamp ,the beauty hear is that you have 4 choices on what kind of tubes you want to roll also please remember a good tube damper such as the Herbies he has several grades and a good power cord
and I strongly recommend using the better Silver fuses on all your gear your detail is clearly better if you gear is respectable.

My Rogue Athena uses a quad of the 6h30 super tube and for good reason they are the most linear small tube made .
My preamp is very accurate and musical their smart parts
decision had a lot to do with that.