If you want something that is cheap, has tubes in it, and has headphone jack, plus plenty of other functions (including bluetooth, optical, coaxial, and phono inputs!), go for Dayton Audio HTA100 (not the "HTA100BT which is the older model)
Granted, the tubes are in the preamp section, the power amp section is solid state class AB, but it's a very nice little amp with great build quality for the price and an incredible 5 years warranty! I bought one as a birthday present for a friend. There are quite a few reviews online.