I don't know the answer of your first question. Maybe you need search posts About MiniBox-D Portable Headamp.
I don't have E500 so I have no idea if it has any hiss. If it does have, people from several Headfi meets should let me know. Fortunately nobody talk about that when they test minibox-d at the meet.
I was told that the battery can standby 70hours. Romanee said that about 2.5 hours of USB connection and it's had roughly 15+ hours so far. If you like it, I will send you for free-to-try.
Originally Posted by nickknutson
Have you had chance to compare your amp to more expensive amps? I was wondering how the sound compares to the Tomahawk. Also, like it was mentioned above, I was wondering if it has any hiss when using sensitive IEM's, such as E500's?
Lastly, how long does the battery last when in use? I noticed it says it lasts 70 hrs on standby...does that mean use or just sitting on, not being used?