[Btdk34]

Hello everyone!  I've been a long-time lurker here and decided to start contributing and asking questions myself.  I recently bought a pair of Beyerdynamic T90 headphones, and I love them.  They have superb soundstage and clarity!
 
However, I've found the T90 to be a very sibilant headphone so far.  I've only used them for around 60-70 hours so far, but I'm wondering if the T90 gets less sibilant with time.  Has anyone found this to be the case?  Also, my current setup is Macbook Pro -> Fiio E17 -> Fiio E09K -> T90.  I've heard that the Fiio combination is known to be a bit forward, and I'm wondering if this is partially why I'm getting so much sibiliance and harsh treble.
 
I'm planning on upgrading my amplifier to the Bottlehead Crack because I've heard it pairs incredibly well with the T90.  Can anyone comment on this/discuss the sibilance issue with either the Fiio combination or the Bottlehead Crack?  Looking forward to hearing some answers! 

 

 

[PurpleAngel]

What is the audio quality like if you go Macbook -> E17 -> T90?
Test using the E17 with USB and optical.

 

[Btdk34]

To my ear, using only the E17 on either USB and Optical sound the exact same to me.  Both are slightly sibilant - the only thing the E09K adds is slightly more bass presence.