Not sure about headphones because I've never had the occasion to listen to my cans with tube gear. But I can instantly tell the difference between my SS and tube amps. Even with my very modest set up. In fact, I was just about to start a thread with the title of "Aaaahhhh".
I love my Hegel H360 integrated but just put my Rogue tube amp and tube pre combo back in the mix and everything just sounds more right to me.
Not sure if this answers your question but there it is.