Afraid no experience with tube amps friskhr, but i am into headphones in a big way.
My audiophile stable includes the Stax electrostatic headphones partnered with the SRM-Mk2 dedicated amp which can be connected directly to the source, in my case the CD player utilising its supplied interconnecting cables.
Being an open ended design, it creates a natural sounding environment, meaning it doesnt sound like youre listening to sound thats "closed in".
Therefore any ambient noise from outside can still be heard.
I listen to it mainly at night for that reason. ;)
Its frighteningly revealing of the recording studio and the flaws of the recording. :o
Made in Japan by a company not into main stream audio.
Koetsu is another brand that comes to mind.
Gary at G