It sounds to me like you're really desperate to buy something new. I read a little bit about the Sound Blaster Z. It has a headphone port that's specifically amped, and it should be more than capable of driving 250ohm headphones.
With a Magni 2, my hunch is that, best case scenario, you'd just be able to get your 990's a little louder. How long have you had the Beyers? Have you spent time just sitting and enjoying them? Have you done A/B testing, with a quick switch? Our brains are pretty bad at remembering what something sounds like, so if you're comparing two headphones you only have a few seconds to switch between them.
I'm sorry if it seems like I'm being hard on you, but I recognize where you're at, and it probably ends with you buying a new amp that makes little difference even though many of us advised you not to. I've been there, I've had upgrade-itis many many times, I get it, it's not easy. My advice, which you probably won't follow, is to use them for a week. Just the DT990's. Get used to them. Give your brain time to appreciate them. Then, try them against your other headphones. If you still don't hear a difference, new headphones will make a much bigger impact than your amp, honestly. DACs and Amps make way less of a difference than headphones do, and I only bought an upgraded one recently because I wanted to plug in more sources, not because I was looking for a magic upgrade. See leng jai's post up there where he barely notices a difference between the bifrost and the Dac Magic.
Thank you!
No, you are not being hard at all. And I fully know what you mean about upgrade-i-tis, ah ha. I just went through it with the brand new computer and all...and for the first time in ever, I was like "you know what, let's take sound seriously, it deserves it". Hence the soundcard and the cans.
I've done some A/B ; not as easy as it could be, since I have to listen to the song, then quickly reach to the rear, unplug and quickly plug the other and put that one. And as I said, from what my audio memory tells me, the Beyer sounds a bit clearer, more distinction, than my Steelseries V2 gaming headset.
It's not about me wanting to buy something for the sake of buying - god knows this PC has cost alot already. It's really just...I don't know. I want to be wrong. I want to believe that all the posts online, mostly at hi-fi, about the width and deepness of the bass and piercing trebles, and that the DT should have a warning sticker on it, all that good stuff. I want my mind to be unraveled. I want my FPS games to feel alive (audio hacks, as MLE put it)
So I just kind of focus into that amp issue since I did read some posts about it + DT990s. Something about the ohms impendence being there but the mW from the card not properly feeding the cans so the drivers aren't be fully driven (but to be fair, it seems to be mostly 2 or 3 posters over at [h].).
Local stores around here don't really do high-end audio. Mostly Bose, some closed-back Sennheisers, some Sony, and some random brands I've never read about...that's it, really. Otherwise I would've went and listened over there and this whole thing would be easier.
To try other headphones - let's say the Sennheiser 598 - I'd have to order them from amazon, and that's like another 200 CAD. Yeah, I could ship them, or the DTs, back and forth until I find my match...quite the hassle.
Maybe I'm just not listening to the right sources either, though ; I have some FLACs of...video games rips, basically, and Stumbleine. Tried to look around for some kind of headphone showcase playlist but ofc a youtube playback wouldn't cut it anyhow.
I do have to mention I went through a lot of upgrades in the span of a month as I was building the PC, though. From a Sandy Bridge motherboard codec, to the Realtek one on a Z170-A (to be quite honest, that jump was the biggest one I've heard so far in my process), to the SBZ, to a proper headphones. Maybe that's why I'm less impressed now than if I had upgraded directly from Sandy Bridge to DT990s.
My home theater receiver is a (very) entry-level TX-SR333 from Onkyo. I couldn't find any details online about the headphones port ohms and mW, but the odds of that having a problem as well are low I realize.
tl;dr. : You are quite probably right, and I will listen to you guys. Just wish my first foray into hi-fi headphones territory would have been glorious.