I own the 900s since early this year. I like them but cant call them perfect or lovely. I think it has to do with my Asus Essense ST card (want a amp now).
Sub-genres like progressive Trance, progressive House, Breaks, Chillout, Ambient, Nu Disco, Tech or Deep House (low BPM's songs with less instrumentals) sound pretty clear with good detail.
However when it comes to Uplift Trance, Electro House, Hardstyle or Techno (songs with faster BPM's and richer/filler/louder instrumentals) sound like crap. They seem too aggressive, high treble, metallic, way too loudy. It's simply unpleasant listening to this kind of genres. I mostly listen to the ones called above with low bpm's either way.
Anyway I might be treble sensitive or something but I think its the card. I read the Essence has a headphone impedance of 10ohm while the PRO900 prefers 4ohm or less of output impedance for driving them optimally. So I'm looking for a quality desktop amp while the Essence will be used as DAC. Like I said I mostly listen low bpm EDM but still want to tame the aggressive highs which occur in other sub-genres. I just want the sound to be warmer, clearer or whatever terms people use.
I'm thinking of the Asgard because of the low output impedance (1ohm) which should be great for the 900s right? Or are there more important specs to check? My budget is lets say around 300 euro. Oh I also use the Audioengine A5+ speakers for exclusive gaming which will go together with the Essence (Dolby enabled). How am I supposed to switch over to the 900s?