I honestly haven't been using the Mixamp + E9 lately, outside of a few tests with the DT990 pro and DT990/600. My computer setup is in another room from my gaming setup, so it's a hassle to disconnect the E9 and take it to the room on a normal basis. The E9 will be permanently moved to the room once I get the C-2.2 amp for my main computer setup.
So I guess for those double amping, I recommend having the Mixamp master volume at around 80%.
Edited by Mad Lust Envy - 1/13/12 at 4:45am