What's the best 6NS7 tube you have tried in your Atma-Sphere MP-3 preamp?

@immatthewj understood, it was meant to be tongue and cheek. Sorry it didn’t come across that way.

Not in pre, but my amp.

Been using a 6F8G for a month now and like it.

About the same as the Ken Rad but tightened up the bass.

From Don Sachs whose electronics use 6SN7's octal tubes.  He has heard most every variant of the tubes and concludes this:

 "In my gear, I use Linlai e series or the Shuguang WE6SN7plus.  The best tube I have ever heard is the new Ray tubes select 6sn7, which is pricey."  He is believes these Chinese tubes are superior in SQ to a lot of the pricey NOS tubes.  He admits that he has not heard the new WE 300b tubes, which might be better, but are extremely expensive.   

@marco1

No, the cv181z were always real stable. That being said, the tube pins and socket connections are sensitve - you just couldn't push a tube in and let it roll. Sometime it's needed a VERY MINOR tweek of the tube - adding a little twist, little bit of lean, or just a reseat is all it would bring it in  Don't discount the signal tubes either

No sweat, @marco1 , I didn't take anything negative from it, I was just replying in a neutral tone.  But thanks for following up.