Ahah, no problem.
I thought about it a bit more and come up with a bunch of possible routes.
Option 1: Denon D2000, Audio Technica AD900
Option 2: Denon D2000, Beyer DT880 600ohm
Option 3: Denon D2000, Audio Technica AD700, Beyer DT880 600ohm
Option 4 (cheap-ish option): Audio Technica M50, Audio Technica AD700, Beyer DT800 600ohm
Every headphone in each route should be different enough from each other right?
Which one would think is a good option to sample different sonic signatures?