which 6sn7 gives the most air??

It has been quite a while since I used an amp requiring 6sn7s.  The ones with the most extended and "airy" top ends were metal-base Sylvanias, which were fairly expensive then, and they were a touch too lean for my taste and set up (Audio Note Kageki amp).  I liked the Tungsol Roundplate and a copy of that tube (Neotron 6sn7).  There was another rare metal-based tube, I believe a GE tube, that was lean and mean and very extended on top--I did not like it and gave it away to a friend.

Sylvania 6SN7 GTA 1950’s are my favorite. Sweet air and extraordinary midrange. Plenty available.

I tried RCA smoked glass, Ken RAD smoked glass, Sylvania Bad Boys, NP EH, Raytheon JANs.  

Is your RCA labled as 6sn7 made in 1950’s?

Then I recommend you to get RCA vt 231 made in 40’s which will give more air and refined sound.

Sylvania vt231 also give lot of air but could sound lean lacking bass.

Tungsol bgrp vt231 also sounds nice as RCA vt 231 but over priced due to hype.

Amperex is a nice tube but not with good air.

Kenrad sounds bass heavy not much air.

I favor 6f8g tubes not for air but for fuller sound.

By the way I had collected more than 100 different kinds of 6sn7 and variants for fun not for business.

I do not sell tubes.

Thomas

If your system sounds bass heavy, it is advisable to try Sylvania vt231.

Tube rolling could be fun to tune your system.

The only bad part is that some hyped tubes get over priced.

Thomas

I favor 6f8g tubes not for air but for fuller sound.

@shkong78  , I just recently acquired the good fortune to have a few pairs to play with in the balanced input sockets of my SLP05.  I am currently playing with a pair of National Unions and I was immediately grabbed by them.  But now the jury is back to being out.  I also had the good fortune of getting a pair of '52 Sylvania "Bad Boys" to roll in those slots, and I am not sure which I like best.