well that is good to hear, Honestly I'm using the NFB 10ES2 for well everything running out of solid state. And I do not think I'll be getting a tube powerful enough to drive an HE 6 for a LONG time. Going for a LD MK VIII SE, nice intro to balanced tubes. Will most likely try the HE 4 and HE 5LE and or HE 500 on the Solid State and tube before I upgrade to HE 6 and amps to drive em. Not to mention I'm grabbing a Balanced T90 soon as well, Want to hear her on tubes as well!