Idly considering buying a headphone amp.
I don't do a lot of headphone listening generally, only resorting to it either when a) my other half is engrossed in some televisual extravaganza which is outside my scope of excitement/interest or b) it's approaching the witching hour and I don't want to annoy the neighbours.
Whilst my Marantz performs faultlessly and effortlessly with 'phones output, I've read lots of good thing recently about the difference in quality gleaned from dedicated headphone amps.
What should I be looking for as an affordable-but-not-crap-entry-level-but-worth-the-effort/expense-try-it-out piece of hardware?