RexAevum

YMMV, but I hated the Little Dot Mk3. It belongs in the trash. I wasn't hearing any of the clarity or bass of the HD650s. The bass was gooey and muddy, overwhelming the mids and the tube haze was really bad with the HD650s. Even the onboard headamp powered it better. My suggestion: Get the Valhalla 2, tube roll it to your choice. Here are a few choices you can look at:
- Russian 6n23ps
-Western Electric 396A + 6922>396a adapter
-Electro harmonix 6922

You could give the Schiit Valhalla 2 a shot since it has a low output impedance for an OTL tube amp. It lets you hear the softness of an OTL but is neutral enough to work with many headphones. Also it's $350 instead.

I have it and like it. I might prefer it to the bottle head crack with speedball I had on loaner, but I might prefer the massdrop x Eddie current zdt Jr. To the vallhalla 2 but I need to do more listening.

Yeah for under $500 I’d go with a Valhalla 2 and tube roll it.

I'd probably agree with the Crack amp suggestion with the Speedball upgrade. Was thinking about getting this one, and from what I've heard and read it may pair well with your LCD-X. Unfortunately, I haven't heard any of the Schitt products.
 
For an entry level tube amp, I've owned the Little Dot MK iii. This Little Dot amp has very good clarity when paired with decent DAC. But, if a person were to get this amp they'd probably want to upgrade the output tubes to the Electro-Harmonix 6H30Pi Gold for more authority. They may be a bit pricey but well worth the purchase ($35.00/tube I believe). A person would also want to swap the 5654 driver tubes with something like Sylvannia JAN's or GE 5-star's. In terms of sound the Little Dot, with the tube upgrades, has excellent detail, but might lack a bit of the bass "body" like what I get from the Audiotailor Jade. This isn't to say it's tighter bass doesn't have good depth, just not as prominent as my Jade. The Audiotailor Jade isn't available anymore.
 
I'm actually thinking of getting another Little Dot MK III. I listen with either the Sennheiser HD650 or the HD600. I occasionally listen with the Monoprice Monolith M1060's but these can be a bit bright and unbalanced to my ears. I'd love to get a pair of LCD-X though. Anyway, that's my two cents.

I have not. I looked into it when my HD 6XX was on order, but just didn't quite want to spend the money.

EDIT: Actually, the Crack may not be such a good choice. It has a high output impedance, making it pretty limited with planars like your LCD-X

Cheap tube amps (below $700) are warm and distorted and suck at neutrality. I like the Bottlehead Crack though, it doesn't try to hide what it is and once fully upgraded is actually quite a decent amp. Avoid the Darkvoice or Little Dots, they are known to cause fires. 
 
Garage1217 stuff is pretty decent I heard so that could be another choice.

This makes zero sense to me.  All of the headphones you have listed scale badly or meh.
I basically agree with everything seduce me said. 
 
If I were you then I would go out and try the HD 800 and HE 6, they both scale pretty well with gear and then once you have actually picked out your next headphones then I would recommend you to save a bit more up so you can get a DAC and amp that is a lot better than your modi 2 u and magni 2 u,  why? Because these smaller jumps are often not that impressive and will leave you with some form of upgrade itch, it might not be there the first or second year, but if you are anything like a big part of the audio community then you will get it. I would also recommend that you find out if you are okay with having two big boxes for your headphones or if you rather give up a bit of audio quality to get it to a smaller form factor 

well they are upgrades, but they would kinda be wasted on Audeze headphones since they don't really show improvements in that regard very well.
 
For 1300$ you can get quite a few options, the Soekris 1421 and 1541 seem to get really good reviews from people I somewhat trust, those have an R2R DAC built in and a very well performing amp, but again I wouldn't really recommend getting one for LCD X or EL-8's.

Since you already have the uber stack, I'd recommend getting the audio-gd if you're happy with your headphones. The uber stack should be sufficient to power all headphones with the exception of HE-6. If you're looking for an audible improvement with a better DAC/Amp, I would save for something more expensive after getting the headphones you want.
 
For headphones, I'd recommend the HD800 with SDR mod. Impressions on SBAF seem to blow any Audeze away with resolution, soundstage and clarity. However if you want us to tell you what you would prefer, it's not possible. You will have to try them yourself personally.

I would go for the Audio-GD IMO. Checking the reviews and specs, it seems to be a better buy. Though the CMA600i does look better and is much smaller in size compared to the other two.
 
For the headphones, I've heard a lot of headphones and for me I'd go for open back headphones if you're aiming for clear and neutral output.
 
Just my two cents

1) Try them out first. I can't tell if you think the cost is worth the subjective improvement in SQ.
2) LCD-3 seems to have more of the 'Audeze' house sound while LCD-X is more of a V-shaped phone based on online impressions. Take with a grain of salt, and both pair well with a good warranty.
3) No idea. 
4) Magni could power the headphones but there are better stuff out there. Only upgrade the DAC/Amp if:
 
You are happy with your headphones/speakers You don't mind spending way more $$$ for that 5% in SQ. You are not in the NwAvGuy cult or browse /r/headphones  If you fulfill these conditions, you can consider the Jotunheim, DIY designs, or cheap tube amps apart from the Deckard. Just avoid the chinese ones. There are many people who firmly stand on the objective side and likewise the subjective side. I am in the middle ground since I don't believe cables make a difference or listen to graphs all the time. It's really up to you to decide.
 
5) Not sure about that, but Jotunheim might be a good pairing with the Audezes. 

No bother.

Right.

My preference would be for SVS SB-1000. Sealed 12", ought to play nicely with the T1s and digs below 30Hz, which is what separates a $500 sub from stuff in the $300 range. None of the subs you're considering go quite as low.
 
My next choice from your list is the Sunfire. It is also sealed and the dual-driver design is interesting to me. Finally, the Martin Logan, which is a well-regarded brand.
 
I'm giving preference to sealed subs (e.g. don't have a bass reflex port) since these are generally quicker and cleaner than budget ported subs, and thus better for music. The T1s are also sealed, so it would be a shame to pair them with a cheapo ported sub.

You would definitely be served better by adding a good sub later on. The F12 is okay for home theater but not really serious music reproduction.
 
The T1 are definitely a step above the Elac B5, no question. If they weren't an option, I would suggest the Philharmonic "Affordable Accuracy Monitor" and an integrated stereo amplifier for around $200-300. This would technically be the more "purist/audiophile" option as the T1 uses a direct drive digital amplifier with DSP (so not bitperfect reproduction). But, the footprint difference is significant; the T1 produce deep bass from shoe box size cabinets and connect directly to your computer. They make a lot more sense as high-end computer speakers.

Vanatoo should be a no-brainier here, unless your only goal is "room shaking" bass.

True dat.

TBH, it's RAM, the specs make little difference. If you want to wait for RGB, then do, if not, GEIL and Corsair both make RGB RAM