[THMMY]

1st Fiio e7/e9 combo
2nd Creek obh 21
3rd dared mp-5 
4th Sparkaudio Mistral Roehren Hybrid
 
I'm between them, which would you choose for mainly rock? Any other suggestion top 300$ (built in dac ftw) is welcome.

 

[disastermouse]

I've got the E7/E9 and I'm quite happy with the sound.  I probably won't upgrade my amp until I upgrade my cans to LCD-2.
 
At that point, I may go Meier StageDAC/Concerto, Violectric V181, or Schiit Lyr.

 

[violinvirtuoso]

For amp only, I would check out the Matrix M-Stage.

 

[Knusperfisch]

I think the M-Stage would be the best choice.
Another option is the Lake People G93 for about 300 bucks. The guys are quite popular over here in Germany but i wouln't bet that the G93 will beat the M-Stage.
 
http://www.lake-people.de/index.php?id=2&lang=eng&typ=3&nr=g93
 
Dang! I almost forgot the Schiit Asgard, it should fit perfectly to the Sennheiser.
http://schiit.com/