Tube Headphone Amp. Getting Started.

I'm just getting in the audiophile game and since I do most
of my listening using headphones, I think getting a good
non-fatiguing tube headphone amp would be a good idea. I
know some DIYers who could build something for me, but am
frustrated by my ignorance - I don't know what kinds of
questions to ask.

What kind of things should be considered (besides obviously,
just listen to the thing)? I figure the process of learning
is probably best served by trying to build a simple amp
myself. A DIY kit? Background reading?

Has anyone been down a similar path? I'm willing to do the
grunt work. Please just get me started with some pointers.
BTW: Headphones HD600 (and now experimenting with the front end). Thanks for your input!
Earmax Pro. Beats my Grada RA1. More musical, less fatiguing, less hi-fi sounding, better seperation of instruments, omg that midrange...... Mated with my HD600's (with the Cardass cable mod)and Pioneer PD65 source, the sound is spectacular for the money. Gives me 90% of the sound quality of my reference $25000 stereo rig. Swapping the stock tubes with NOS (I'm using Telefunkens CCa's and ECC801s's, makes a huge difference too)
Happy listening
Misread the post, thought you wanted to buy, not build a tube amp, I was drinking.
The Earmax still is amazing though!
I'd suggest visiting and There's lots of info on both store-bought and DIY headphone amps. good luck.
I use an Antique Sound Lab MG Head OTL w. HD600s. Very inexpensive for great sound. The HD600s never sounded good until I added the headphone amp. I was using before the headphone output of my Placette Preamp. It was very clean, but not alive. The ASL is very musical & synergistic w. the HD600s. I haven't tried anything else though, but for the price it was an easy choice