Headphone Amp questions

[Max Sutter]

I just bought a pair of Audio Technica ATH-M50s and everyone's saying I should get an amp but I know absolutely nothing about them. Are they necessary? Which ones are good? Will I be able to use my 2.1 system alongside it? If any of you could answer even some of the following questions that would be a big help!

 

[C12Friedman]

I've found these videos about the Objective2 ODAC with AMP quite informative. It was designed by NwAvGuy and is open source, it is purported to be one of the most "transparent" DAC/amplifiers available. It is currently produced by Mayflower Electronics and JDS labs (it's the same either way)
https://www.youtube.com/watch?v=d1rXcJuEsy0
https://www.youtube.com/watch?v=i33wY_RQGII
https://www.youtube.com/watch?v=89pjq1mGstA