I bought an expensive Seinheisser headset from Amazon but sent it back because while plugged in to my PC, I couldn't seem to directly adjust it's performance via 3.5 plugin, So I replaced it with a Steelseries USB headset which I could actually use my Soundblaster X-Fi to adjust the sound. The quality of the Steelseries is not what I want so I'll be upgrading to a high end set. I know I can get the Astro A40 for 250$ with the amp. Is that the difference, do I need to buy an Amp to get decent directional sound and such from the non-gaming higher end headphones?