so i have a msi x99s gaming 9 ack whit the option of connecting the sound part of the motherboard directly from the powersupply instead of draining it from the motherboard itself (i dont know if this is pure marketing or actually does something to the sound quality) and my headphone is a sennheiser hd650, i want to clarify that i dont have any problem whit it, i just want to upgrade my audio quality, there is no budget, but obviously dont list me something that only high end studios can buy, i dont know whats the difference between graphics card and a DAC, what does each thing do, what are the pros and cons of it, or maybe you guys can just explain to me something to buy that will raise my sound quality and search something that fits my tastes and my budget.