Hey
@Limu Shirin - I have just checked and no the SE846 do not hiss to my ears (or it is so slight that you would probably never notice it - YMMV if you had very very sensitive hearing!?) - this applies to both when the player is silent and playing music (I play tracks at about volume level 40 on the PD and even when the music is paused and the volume is turned all the way up to 100, I couldn't detect any noticeable hiss).
Sound (to me) with the blue (unmodded) filters and with the Shure Olive tips, I find to be slightly warm (normal Cowon sound) but is clear/well defined and has tons of detail (and of course you will get the SE846 bass). The PD also has JetEffect 5 and it’s EQ capabilities are plentiful, so you can always adjust to your own taste if required (I don't personally use the EQ on DAP's and so can't comment on how this adjusts things but there are about 40+ presets to play with !!)
Hope this helps.