The point is, right now I had so little time playing with my audio stuff.
Few days ago I grab my audio gear again and play my favorite music. If you know my review here about the Beyerdynamic DT880 headphones, you know this headphones is not for my taste. The high frequency to sharp and somehow less engaging to the music. I do some mixed and match amplifier with this headphones and I got a suitable amplifier for it. It is not more than a Cmoy amplifier with regulated power supply. It is cheap to built one and I guess I should recommend you to do the same if you want your Beyerdynamic headphones sounds better.