Thanks a lot, I'm glad I can help. 

Lots of questions, I'll try to sum-up as much as possible (with some quick comparisons to the other HE series headphones you've mentioned).   -The HE-4 is lighter than the HE-400, HE-5LE, HE-500, and HE-6. -The HE-4 is more spacious sounding than the HE-400, HE-400S, HE-400i, HE-5LE, HE-500...

  I am using the Amperex Bugle Boy 6DJ8 and I have a really loud noise floor with the TH-X00?

I mentioned this a couple pages ago. I did not experience the TH-X00 out of Ember without a very noticeable noise floor. The noise is tube dependent, but most people have not experienced the Fostex TH series on Ember without noise.

Very sweet. I'm hoping I'll get that kind of impression from the Beta22. I'm not ready for a 2k amp investment... yet. Hard to pass up deals like that though.

Nope, haven't had the privilege of trying a speaker amp yet, but I will when I can. I had the Emotiva mini with my HE-4 at one point and while it had more bass it was pretty terribly grainy across the spectrum. I'm sure a good speaker amp would be much better.   I can easily see someone...

Naw, I haven't tried my HE-6 with a huge power amp. It only needs ~600mW to get to 105dB, so it makes sense that the Vali 2 and Ember have no issues getting to listening levels.   I do, however, have a Beta22 amp build on the way. Hopefully she'll be built and test ready by next spring 

Ember does just fine with the HE-6 (low gain, 12 o'clock). I just recently picked up a Vali 2 as well and, believe it or not, it has plenty of juice to get the HE-6 very loud (normal listening at 2:30 on high gain). (Cue speaker amp zealouts.)   For the HE-4/6, Ember has more treble and...

The HE-6 is by no means a giant leap from the performance of the HE-4.   HE-4: More bass, more air/bigger soundstage, hit or miss treble, better comfort/weight, better price, fun and aggressive.   HE-6: Blacker background, controlled, less distortion, more reliable treble, very immersive...

Hah! I can definitely agree that it's unfortunate that G1217 isn't getting as much hype as the Vali 2 when they've had the single tube hybrid concept for a looooong time. Plenty more options to suit your needs too. Seriously. Again though, the Vali 2 just appears (spec wise and price wise) to...

@HOWIE13, I agree. Based on specs, G1217 has a lot of competitors to the Vali 2 but you may be right about Starlight being a more direct competitor.   Ember and Vali 2 are different enough that I somehow justified needing both. Why I chose Vali 2 over G1217's other offerings is sort of random...

Let me clarify, since I don't want to upset the hype train:   1. Project Ember is the best amp purchase I've made to date; it has the best value for the price. Period. Ember has so many possible configurations and it can easily drive my HE-6 without issues.   2. Ember does have its faults...

The amp is twice as expensive (almost) and is very limited in the amount of tubes you can try. Your argument can easily be used against Ember.

For the headphones that you have, both amps will provide plenty of power. That's no problem. Ember has more setup options but it also is not a good match for IEMs or other highly efficient headphones. My Fostex TH-X00, for example, have a very noticeable noisefloor when plugged into Ember at 0...

Hah! Just get me an STL file and I can do the rest.

Okay, I'm jelly. Now you have to figure out how to change the "HE-400i" into "HE-5LE". 

@Mshenay, definitely check out the DIYAH forum for more G1217 info too! Both Jeremy and Frans are pretty active over there.

I haven't heard of these, I'll look into it.

Nope. Frans (Solderdude) does the majority of the amp design and architecture, though I'm sure Jeremy gives input, especially on aesthetics. Jeremy does the business side: customer service, soldering, website, sales, etc.

Yes, Solderdude is the designer/engineer of the Garage1217 amps. He helped me quite a bit over at his site (DIYAH).   The filter can sit wherever you want. I've only had it in a breadboard for testing, basically in-line with the headphone cable. If you really liked the effect, you could end up...

Thanks to Solderdude's filter design (seriously, I didn't do any of this myself) I've been able to try a couple configurations with the intent of lowering the intensity of the HE-4's treble. This filter is merely a circuit of resistors, capacitors, and inductors. The "full filter"...

Star felt on my HE-4 is/was grill side.   Star felt on my HE-5LE is both sides.     Are we just now discovering several different 4/5LE revisions? Neither my 4 or 5LE had any foam whatsoever...

The quickest fix is to just flex the headband back by hand. Just hold the insides of the headband (not the cups, since the gimble/headband connection is weak) and stretch it out a few times. The books will achieve the same result, it will just take longer. And, depending on your pads, it may...

I wouldn't be worried about the Ember breaking. It has an open chassis, sure, but it's not like it isn't robust.     I received my 5LE's this weekend. They are definitely in stock form (they have the star felt pattern on both sides of the driver, but not any foam @mrscotchguy). They also have...

Hah! I don't have the real-estate for a vintage amp (yet). I need a bigger desk! As far as DACs go... I'm looking to upgrade my Bifrost to MultiBit soon...