it is a good post, but well he has some strong opinions and feels everything should be by the numbers... that's his choice
that said, I notcied my oDac [created by u can guess who] added an immediate sense of openess to the sound of my crummy little Sony XB 700 :3
the amp also fleshed out the bass of that very same $80 headphone. Granted at the time neither my dac nor my amp costed much but they made a noticeable improvement.
How ever Money makes a good point, if you do not like the Sound Signiture, of your headphone [warm, bassy, or bright with forward mids] if you do not like how ur current headphone sounds a Dac or Amp will not make them sound different, the improvements of a Dac and amp are subtle, as you move up with gear they become more evident but an Dac an Amp will enhance how your current headphones sound. By how much depends on you and what your listening to.
Or another and better example would b my Beringher UAC 202 [recommended by u know who] is a very nice dac! I like it for streaming netflix and watching videos in general. I got it to reduce the noise is had from my lapTops headphone out. While most PC dacs might be acceptable... the circuits for the headphone out can b nosiy, depending on what your lap top is. Not to mention my DT 880 NEED AN AMP. And it is NOT GOOD to feed an amp with an already amped signle! So you use a Dac to feed a fixed line out to your amp to once again reduce your distortion.
I find dacs and amps even intro one offer worth while improvements, and honestly the Schiit Stack would be a good intro amp and dac that would last you again through a PLETHURA of headphones. I finally found a dac and amp I can live with till I get an End game Headphone, cost me $600 for the Combo Unit.
So that said, I'd go with the Schiit Stack. From there you can feel FREE to roam the wide open world of HEADPHONES and amps GALORE, I would say get teh Audio GD 15.32 but it would limit your upgrade options :3, I how ever enjoy my Audio GD 10 NEB ES2 enough to stick with it for a while :3, which is nice because Audio GD amps are for the money VERY VERY good [Schiit is also very very good as well]