Great stuff, good review. I'm more curious on your Paul Hynes PSU for your CAP's music server pc though. hehe
 
Also, what tube amp would you consider to pair extremely well with the HD800's? One that is still in production...

Nice review. I have to say, though, I'll never understand this idea of an "audiophile" as some glorified, uber-rich person with golden ears who is so OCD that they must have *perfectly* accurate sound, which is basically a unicorn...especially when it comes to headphones.
 
The literal definition of an audiophile is someone who loves sound; I will never understand why some people feel that budget limitations or differences in opinion or taste contradict the core concept of being a "sound lover." I would say that anyone who takes the time to create an account or lurk regularly on a place like Head-Fi is probably an audiophile in the strict sense, and I don't understand why it has come to be such an exclusive term rather than an inclusive one.

Thank you both for the kind comments. 
 
@DefQon - The Paul Hynes linear PS is very special and mates with the CAPS extremely well. It has three different isolated rails each with its own PSB. The CAPS server takes three different voltages, so each rail is set to mate with each individual component. Honestly I haven't heard the CAPS without the PSU, but from what I've read, most people upgrade the PSU to an external linear unit of some kind. Blacker background, great sense of depth in the sound, etc. as a result of the upgraded PSU. I believe this unit costs around $2200. You can now get a SR3 from Paul for quite a very reasonable price. 
 
The two best tube amps I've heard with the HD800 thus far are the DNA Stratus and the EC BA. I had a very short time with the EC 2A3x4 which was also very nice. Not enough time to get a handle on its sound, but it seemed like it could have been the best of all three. The Stratus I have in house right now and it is quite impressive. More organic than Craig's stuff and maybe a tad less clarity and detail, but a very pleasing, non-offensive sound that you could listen to for hours. 
 
@Gilly - I agree that an Audiophile must love music (sound) in order to keep going, but I've found that throughout my time here and on other forums the word Audiophile is used more as a title to flaunt their ultra expensive gear. I don't know how I feel about this definition - but you always hear about that Audiophiles analyze, Enthusiasts enjoy or Audiophiles listen to their gear, not the music. Not sure how much truth there is to those statements, but I for one don't want to be a part of a group that feels they need to be critical. I guess the word is highly subjective, but no one can argue that audio gear is extremely expensive past a certain threshold. Most people will never be able to afford them and therefore don't title themselves as Audiophiles because they are limited and can't experience the "best" the market has to offer. 
 
Either way, I totally understand your point of view and agree I wish the word would be defined as by their love for music, other than their love for music/gear. 

If you think the GS-X has a weird treble have you gone down the line in the Dynalo range?  The Gilmore Lite has a harder more etched treble in my experience but gives up that bass control you mention.  These amps are overall great for many headphones but like you I did not like the HD800 match and prefer more warm/tube combos, I really like the Zana Deux and would venture to guess it may be a better call than the ECBA!
 
And on power, I wish I could hear some HE-6 myself but back in the k1k days I found great sound out of an "underpowered" EC2a3 amp while really not caring for a First Watt F1 in comparison; sometimes sounding great can trump the technical merits of having tons of power on hand.  The difficult part is getting over that psychological barrier of enough is enough.

@Ricky - I've briefly heard the Gilmore Lite but it was paired with a NOS Tube DAC so no immediate piercing daggers were present. I'm sure with more time I would have picked up on it. Generally, I'm not against any Dynalo, but I do understand that they all exhibit some sort etch or hardness to their treble. 
 
In regards to the HE-6, I can understand and respect that for sure. I feel like synergy is much more important than going by how powerful an amp is. I guess it really comes down to personal preference. I found the F5 to be a superb match. Haven't heard the F1 though, so I may feel differently with that one. 

@Greed, great review.  I love your disclaimer. 

Great review.

Way to go Eric, good review.   I think the Technical Specifications:  are for the GS-X mk1.  I may be wrong though

@Darryl - It is possible, I grabbed them from the website. I'll double check and edit if so. Thanks for the heads up.
 
Thank you for the kind words guys. 

Phenominal review with fantastic photos to match. Kudos.

Loved reading your review, beautifully written.
You added the color to the  painted the picture in my head of what the M9 can do.
Very interesting comparison with another great amp the GSX-2.
I only wish I could explain things like you did....You did it the KISS version.
(keep it simple stupid)
Simple maybe, yet effective. Well done....