Please, somebody answer tfarney, and his direct question about the headphone section coming directly off the amp (NOT just the preamp) via a nest of resistors.
My experience is that that can sound exquisite, when that is the implementation method, as with the current Denon integrateds.
As Unc sez, pure pre-amp implementations can be hit-or-miss or sorely lacking, as in the hole on my current Onkyo cd player, which is weak-kneed and only good for monitoring-the-signal purposes (unless you're an uncouth lout).
I remember thinking, as a poor college student in the late 1970's, that I could run a pair of Koss/Radio Shack Realistic cans out of the jack on my solo component, a Pioneer cassette deck.
Yikes. Flat as a pancake. Just like my current Onkyo cdp jack.
Yet this last winter, I found the Denon integrated amp that I bought for like $1100 from Crutchfield to have about the best headphone-out performance of any dedicated headphone amp that I've ever had or ever heard. I was told by Denon that they resistored down off the main amp.
Dennis Had, I believe it was, also told me that that was the way that Cary does things, which, he said, "is the preferred method," and produces the great headphone sound quality that their products exhibit.
So, yes, it's hit-or-miss, but I think that this forum has a profound amount of confusion and ignorance on this topic, and an unfair bias toward dedicated amps, many of which are remarkably nothing special (except for their expense or style).
