No. At normal levels, you really wouldn't be aware of hiss. It's extremely low level and is there at zero volume. It's just that my ear tends to focus on tiny things like this as a matter of habit.
That's why I'm saying that higher impedance headphones are better with it. You get nothing then. Grado headphones show it ..... Just.
You have to hold your breath and make sure you're in a quiet room. It's easier to hear if you pull the plug out while the headphone is on your head. Then you become aware that it stopped.
Tbh, it really is nothing but someone mentioning that they were plugging an iem into it made me say that noise would be an issue. (And he found that it was)
In fact, it surprises me that people would want to use an iem at 16 ohms with one tbh. Just a mention because I know that there are lots of Grado users who may find similar if they have bat's hearing like me.
You could even mistake it for a form of tinnitus and think that it's your ears hissing. It's EXTREMLY low and nothing to worry about.
With higher impedance headphones, it doesn't exist.