Dude, seriously... I stumbled upon this thread which is fairly old but I must reply because I was in the same situation as you a long time ago when I was into gamer crap.
Your current 7.1 headset is utter s*** and you should do yourself a favour and getting rid of it. "Surround" headsets are absolute crap and a complete gimmick, they're terribly overpriced, sound like garbage and nobody in his right mind should be using them and falling for the marketing. You got so used to them that you can't tell what sounds good anymore if you don't have a bunch of awful sound altering mods going on.
Many years ago, I became really used to utter garbage Creative """gamer""" headsets that when I bought my first pair of decent headphones I thought they were horrible and the Creative were the best in the world. It took me a month of using the new headphones to adjust my brain to proper sound quality and proper ergonomics before I realized the Creative were complete irredeemable overpriced trash. Everything branded as "gamer" is trash 99% of the time.
You got so used to your horrendous software sound gimmicks that proper sound quality sounds weird to you. Please do yourself a favor and turn off all that crap, turn off all surround effects, all EQ, everything, plug your headphones directly into the motherboard (your mobo does have a good integrated sound chip so you don't need a DAC at all, by the way the 599 doesn't need an amp), and listen to the music for a few days, you won't be able to go back to whatever garbage sound mods you were listening before, trust me. It may take you some time to adjust and "detox" from the awful mods you were using but once you experience proper sound quality you will never go back to using those mods and gamer garbage.