headphone setup 500 used.

I'm tired to listen to freequent arguments from my wife which music I do have to listen. That's why I wish to get an inexpencive combo(prefere tubes) for headphone setup(amp/HF). Most of the time I'll be listening to "forbiden" or "banned" music that drives her crazy(well I can understand that). I listen not only to a traditional stuff but avant-grade, underground, progressive and many many kinds of "other music" most of my listening time.
I need non-fatiguing and comfortable to wear headphones that will be connected through headphone amp to my passive preamp.