I just try the exact same set up as yours. MBP 15" + Chord Hugo + SE846 = Zero hiss.
Here is what I tried in my office this morning. I close my door and make sure my colleague talks quietly, so room is dead quiet.
There is an almost inaudible hiss.. very very faint. Almost nothing.. I did not really hear hiss, I heard a sense of space instead of hiss. This is done with music pause and volume at max.
I think its better to send it back for a re-check. The chord Hugo is design for IEM, there should not be any hiss.
Thanks so much for trying this out, especially during work hours. Your experience has been really helpful.
And yeh, it does seem like something is not quite right on my end. I'm definitely hearing obvious hissing with the exact same setup, even when the Hugo's volume is turned way down, regardless of whether the music was playing, paused, or not playing. Rob Watts advised me to use the inline volume attenuator, which dramatically reduced the background noise, however, the sound quality noticeably suffered when using the attenuator.
On the other hand, when I change my setup to MBP + Woo Audio WA7 + 846 = no hiss even at maxed out volume.
Edited by daveyston23 - 7/7/14 at 6:08pm