Well, I had been out of the Head-Fi loop for a while and was feeling somewhat uninspired by my CEntrance M8 - it's a very competent and versatile piece of equipment, but its somewhat flat sound never left me feeling very inspired. So I decided to check out the current top options for portable DACs, and was trying to decide between the Aurender Flow and the Hugo. I ended up going with the Hugo because of the lack of reviews of the Flow in comparison to the Hugo, despite Jude's review of the Flow which noted that the Hugo produces hiss with sensitive IEMs. His opinion almost seemed like an outlier, since I read every professional review I could find and many pages of Head-fi reviews, and only saw a few mentions of the Hugo producing hiss with IEMs. Indeed -
Chris Martens' review of the Hugo even used the UERMs and never mentioned any issue with gain or hiss.
So I was disappointed to plug my UE Reference Monitors into my newly-arrived Hugo and hear a
very audible hiss, even with nothing else connected to the Hugo besides my IEMs (and obviously no music playing). I've had this issue with so many portable amps and iDevice transports that I can't believe there isn't more discussion of this problem. I know my ears aren't supernaturally sensitive, so I wonder how people can simply discount the added haze that the hiss adds to the music.
The sound quality I'm getting so far from my Hugo and the UERMs is nice, but it's extremely hard to ignore the muddiness added by the hiss. Unfortunately, it seems clear to me that the Hugo, like many other DAPs/DACs/amps deemed "portable", were not meant for use with sensitive IEMs - which makes no sense, since IEMs are the most portable headphones out there. The M8 with the low gain mod had a completely black background with my UERMs, as does my Leckerton UHA-6S (after getting the gain lowered by the manufacturer), but basically every other "portable" unit I've owned had an intolerable level of gain with IEMs - this includes the HM-801, CLAS, Solo -dB, HP-P1, and TTVJ Slim.
I'll keep listening for a few more days, but I may be forced to either sell the Hugo or resign myself to only using it with over-ears. Right now, I'm just amazed at how this issue wasn't mentioned more frequently in the hundreds of pages of Hugo impressions.