I have an HD380 Pro which i like very much because of it's bass and soundstage. Through my MacBook Pro DAC they sound dry, sibilant and congested. I had an HD 598 in the past which suffered the same problem, but one day i amped them and the soundstage became wide left and right, clarity improved and the bass reached deeper. Voices sounded very natural and realistic, so i think my headphones are not the problem here.
I also had an Grado SR325is which i loved very much and they clearly can sounded even better than what i heard through the Mac.
This thing can put 2V rms full-scale if i'm not mistaken. This is way more than what both headphones (HD380 Pro and SR325is) need to reach 100 dB SPL. But despite that they sound AWFUL through this thing. Doesn't matter if this thing has lower THD than, say, some expensive tube amp, it sounds AWFUL, horribly awful. My ex-Grados screamed a better source back then, but even through the Mac they sounded better than anything i've ever heard until today.
This experience made me think about the 'objectivists' buying something like an O2 or Benchmark DAC2 thinking they have the best sound quality just because they measure well. What about amps like famous Eddie Current's Zana Deux and Balancing Act?, real audiophiles say that they have the blackest background and they can extract the best soundstage your headphone can put, but they are more expensive than well-performing headphones. For example, an HD 650 costs 400$ and someone will never heard their true potential until they audition it with something like an Eddie Current amp. I heard people complaining about poor sound with HD 650 + O2, and yet the O2 measures perfectly, and the Eddie Current's are 'distorted' tube amps, yet i'm sure they sound a lot better and you'll can see why.
Because of this misinformation i can't take this hobby seriously. In my experience measurements doesn't mean GOOD SOUND, despite what the scientific-wannabe people say. Conformists.
That's why i want a tube amp. I hate sibilance. Thank you.