I am relatively new to the hi-fi headphone population, but I do have some experience in home theater audio so I'm not a total n00b. However, I am at a bit of a quandary when it comes to Amps and DACs. I just got some Sennheiser 598's not too long ago; I am happy with the performance, but I know I can get them to sound even better. Right now, I have them hooked up to just my computer through the motherboard, which has a pretty good built in sound card I believe
(http://usa.asus.com/Motherboards/Intel_Socket_2011/RAMPAGE_IV_FORMULA/) .
I was looking at the Schiit Magni and Modi, or both if necessary. The only possible issue that I came across was that the Magni amp produces frequencies between 20 & 20 khz, whereas my 598's produce 12 - 38,500 khz. Would I notice this while listening? I would appreciate it if somebody could point me in the right direction lol 
-Thanks



















