Jdnoss1234

The HD6XX are in a different league entirely from the other headphones you listed. However, they are 300 ohm which can give even motherboards with high end on-board audio a run for its money. Check out the HD58X Jubilee, they have half the impedance so you can make better use of them without an amp. As for surround sound, it is really just a gimmick. The A50s are just stereo headphones with a bunch of software and DSP correction to make up for the fact that they are not particularly good headphones by themselves. A good pair of headphone will give you those same effects if the game audio is worth a damn. Many modern FPS games will use HRTF method for positional audio when you are using headphones, some use Dolby Atmos for Headphones. This will give you a binaural effect in games. Try some regular headphones and watch some videos from The Sound Traveler or a video called virtual barbershop.

I would say Phillips SHP9500s. The beyers and Sennheisers are also good options. If you catch the SHP9500s on sale you could probably swing a Schitt Fulla otherwise a Fiio E10K will usually do the trick.
 

The Fulla 2 is plenty for the K7XX and the Magni would only add headroom for hard to drive headphones like planars. If you don't plan on making headphones your hobby, save the money. 

Koss Portapros are better.

best earbuds under $40 would have to be KZ Zs5

Am I the only one who actually buys CDs and rips them myself?

So all dac's need that have an amp. The difference is whether they are in the same box or separate ones. The Schiit Modi 2 is of the latter. What you are really after is the Schiit Fulla 2 as it is the best for that price. The better question is do you need an external dac and amp? What headphones do you have? 

Get a fulla 2 or nothing, end of story. 

Yes That is the ODAC and sonicly they are both very good so I would base my decision on dollars and features. With an X7s you will want RCA output to keep crosstalk to a minimum. So, the ODAC will run you $170 new or about $120 used with RCAs and will be USB only and powered by USB which means no wall-wart.
 
The OL dac is $140 and already has RCAs, but it isn't likely you will find one used. The OL DAC also has optical SP/DIF which is handy if you want to hook up to something other than a computer or if your computer has noisy USBs. The OL DAC has and external power supply which is good to lower the noise over USB if it is a problem but then you have another power adapter to deal with. 
 
So, think about what features you want (compact and simple vs. larger and full featured) and how much you are willing to spend and if you want to buy used. You can't go wrong with either one. 

The ODAC was designed by Nwavguy and Yoyodyne Consulting to be a very clean, good measuring DAC as an FU to much more expensive units at the time. Is it better than the modi 2, I own both and I cant really tell a difference.  I own a couple of them and they are nice because they are small and easily hidden away compared to the much larger modi 2. Now JDS labs has the OL DAC and the EL DAC. They were designed by JDS labs. From what I have herd the OL DAC is very good with similar functionality to the Modi 2 Uber. The EL DAC isn't worth it in my opinion, just too much money for what it is.

In terms of sound the HD 650 is superior. Sure, the K7XX may be better in one or two categories such as bass quality and quantity, but overall the HD 650 has the advantage in response, integration across the frequency range, and technicalities. As with anything subjective, some may find the sound K7XX superficially more preferable.
 
Expanding on the point about the HD 650 being better built, keep in mind that nearly every part of the HD 650 can be replaced by the user without tools (once the warranty runs out, of course). This includes the drivers, which do not require soldering. IMO this is a significant advantage and an oft overlooked engineering accomplishment of Sennheiser.

what about the status audio cb1's? Z reviews was super positive about them.

Yeah go those!

I have the Blue Snowball and it works pretty good from a distance but way better close up so I put mine on a boom arm on my desk. If you can spend a little more than that the Shure MV5 is great and way smaller than a snowball https://www.amazon.com/Shure-MV5-Condenser-Microphone-Lightning/dp/B010W6W9EQ/ref=sr_1_13?ie=UTF8&qid=1500654848&sr=8-13&keywords=shure&th=1.

I use Voicemeter or Voicemeter banana from VB-Audio.

You can use pretty much any [reputable] single tower heatsink. The better question to ask is "what cooler should I get for my case?". 

Go for a highend air-cooler (Noctua, Cryorig) or an AIO watercooling unit. I own a H100i v2 since a few days and so far I really love it's efficiency. Coming from a Thermalright Macho 120 Rev-A.
 
I think you should go for a custom watercooling-loop then.

If I were you, i would just pick up:
 
- Philips SHP 9500 for ~$70 (Newegg or Amazon)
- V-moda Boom-Pro ~$30 (Amazon)
 
That's all you need really. You get the comfiest, lightest pair of headphones with a mic that puts every headset to shame. And the sound is so good! 

Ok apparently you miss what I was getting at. There is a difference between exaggerated sound stage, Realistic sound stage and no sound stage. The M40x's fall into that no sound stage bin, but than again the choices under 100USD  are slim to none. I myself like neutral, most of the time, but then I put on a pair of Vmoda M100's and go "ya bass".