I've been wondering for quite some time now...are any of those professional wide profile (meant for use in studio racks) headphone amps with multiple outputs any good? I see loads of them on pro audio gear web shops...stuff like Behringer, Presonus, Samson, SM Audio, Rolls, Art Headamp, etc. They all range somewhere around 200-250 dollars for 4 to 6 outputs, and they in general have pretty good specs, certainly good enough (above what is audible) THD, SNR, frequency response, usually around 350 mW of power output per channel, etc., almost all of them have balanced XLR intputs as well, and on top of that they have some basic EQ settings as well. So on paper they're not bad, but how do they sound in reality? Does anyone here have any experience with such types of amps and which headphones did you use? Some examples: http://www.thomann.de/gb/art_headamp_6_pro.htm http://www.thomann.de/gb/sm_pro_audio_hp6e.htm http://www.thomann.de/gb/art_headamp_6.htm http://www.thomann.de/gb/samson_sphone.htm http://www.thomann.de/gb/behringer_ha8000_powerplay_pro8_headphoneamp.htm Or even some cheaper stuff like: http://www.thomann.de/gb/samson_samp_headphoneamp.htm http://www.thomann.de/gb/art_headamp_4.htm http://www.thomann.de/gb/presonus_hp4.htm I mean, how bad can they be, even for under 100 dollars? 'm seriously close to pulling a trigger on one of these...just for the sake of it, take it apart, see whats inside, maybe mod it with better components, etc.