Another positive experience with NAD headphone outputs. When I first got into headphones, I used the headphone output of my NAD 1600 preamp/tuner to power a Senn 650 and Grado RS-1. It sounded pretty good and drove both cans effortlessly with practically no audible distortion or noise. Some people around here automatically assume the outputs from non-dedicated headphone amps are all inferior.
I later got a "real" headphone amp, a HeadAmp Gilmore Lite. I did an exhaustive A/B/A comparisons between the NAD and GL using the 650. I even level matched their outputs using a SPL meter, something most of people neglect to do. The NAD was a little "warmer" sounding and a little "darker." However, the differences were quite close. I certainly wouldn't wage money on a blind test.
I can't really say which was better, it was a matter of taste.
I wound up selling both the NAD and GL because I later got a GS-1 and used it as both a headphone amp and preamp for my speaker system. I mainly did this to reduce the clutter.
