Originally Posted by goodvibes
Does it hiss a lot with the volume turned all the way down or with a shorted input? Just curious how much is the output stage. If the hiss just goes up with volume, it's not that big of a deal. The output adapter is really the wrong way to go for almost all IEMs. Thus seems to be made for less effecient high impedance headphones and may be great for that purpose. Forcing it into High effeciency low impedance IEM use may be doing it an injustice. It really shouldn't work as well that way.
Testing with nothing connected at the input:
The hiss is constant and not volume dependent.
On my HD 25-1 II's the hiss is barely audible.
But on my high sensitivity IEM's, the IE80's, it is loud enough to be audible during soft passages. And definitely audible when nothing is playing.