Okay, I hear what you're talking about now, but it's not piercing. Listen to Jacques Brel's "Dulcinea" for some real sibilance.
The point I'm trying to make is that it depends more on the recording than the amp. I'd like to see an FR graph of the Duet if it actually reduces sibilance.
There is a one decibel increase at 17K. I EQ this out in my player. But those recordings that I had a problem with are noticeably better. The raspy voice of Bob Seger on some songs, like Hollywood Nights, which are part of his greatest hits album where there is allot of clipping, is not bothersome to my ears anymore. Enya on her greatest hits has on one song, Amarantine, what appears to be a type of distortion when she sings to a very high note also does not bother me anymore. The most apparent is the soundstage has depth. The difference between the O2 and Duet is very noticeable to me and others. The timbre is more full-bodied and accurate in my opinion. There is no way to EQ this when using the O2 to make the music sound similar to the Duet.
Based on my experience with both DAC/amps, I think it is both how the music was mastered and the DAC but primarily the mastering of the recording that makes the difference.
I hope this makes sense. FWIW
Edited by r010159 - 6/9/14 at 6:53pm