Audiophile help needed! Dac/Amp/Soundcard + Headphone question

My mobo has 7.1 CH HD Audio with Content Protection (Realtek ALC1150 Audio Codec), the onboard dac provides up to 24 bit/192k audio playback and/or recording(?). If this is the case, would my desktop still somehow benefit from a budget external dac? Would it provide for less "jittery" sound?

What dac/amp combo, or just amp (or even headphone amp) might you recommend for around maybe up to $150ish?

Currently choosing between Senn hd600, Beyer T-90(chrome edition, because the newer edition is more expensive and I cant for the life of me figure out why), used Denon ah-d2000, or, possibly, a lower tier beyer, eg 770/880 or even 990. The denon, discontinued, is ironically the most expensive on the list (despite having to choose a used model) is a 45ohm pair of cans with a unique sound that I'd love to try. Though another reason I'd love to consider it is because it seems like an ideal choice for comfort, especially for someone with a somewhat large cranium and big ears to go along with it. The t90 chrome is available for as little as $250 sometimes, though the thing about all (affordable) beyer cans I intensely dislike is their non-detachable, single wire connection. Not that senn is any better with their proprietary connections, though at least both cups are wired.

Any help or suggestions would be much appreciated. If you believe there's a better way to go (lower priced fostex, for expl, or w.e) I'm all ears. =)
 
Solution
Yeah, you can drop the DAC completely rly if you don't have the budget, it's not necessary by any means. :)
The 650s are imo much better than the 600s, and are quite a large jump in quality.
Well worth the $40 difference.
PCPartPicker part list / Price breakdown by merchant

Headphones: Sennheiser HD 650 Headphones ($319.12 @ Amazon)
Other: Magni 2 Headphone Amplifier ($119.00 @ Amazon)
Total: $438.12
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-12-03 01:00 EST-0500


I thought about that schitt, I truly did, and sure, I'd very much love to go with that option. However, why would I need the dac? It'd also exceed stated budget of around $150ish (really would like to find an option that doesn't exceed a buck tbh). If my mobo already has a passable dac built in, will choosing a modi or some other dac really help all that much? What other phones might you recommend btw? The 650s are decent, though there have been some complaints re fatiguing highs compared to the 600 iirc?
 
Yeah, you can drop the DAC completely rly if you don't have the budget, it's not necessary by any means. :)
The 650s are imo much better than the 600s, and are quite a large jump in quality.
Well worth the $40 difference.
PCPartPicker part list / Price breakdown by merchant

Headphones: Sennheiser HD 650 Headphones ($319.12 @ Amazon)
Other: Magni 2 Headphone Amplifier ($119.00 @ Amazon)
Total: $438.12
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2016-12-03 01:00 EST-0500
 
Solution


Man I totally lost track of this thread, I just wanted to say thank you Chugalug and much appreciated. If it's ok by you, I may end up posting the solution I end up going with, just to let you know how it works out. Again, thanks man and much apreciated.
 
Haha no worries at all. :)
Just run it by me to make sure the headphones/amp are of good quality.
Some good recommendations are Audiotechnica, AKG, Oppo (PM3s) and Sennheiser's HD line. (600, 650, 700)
Head in to your local audio store or tech retailer to try out some headphones, personal preference is always a factor with these things, and what another person likes the sound of you might not like.
If you listen to rock music for example, mids and bass may be more important to you.
if you listen to alternative, a balanced headphone is a good choice.
For pop, treble. It all comes down to the material. :p