Assuming good source / recording my three favorite are the Dynahi, GS-1, and Headamp GLite. My ears are clearly not as refined as some here, because unless I am really paying attention, and can't tell the different between these three. Hoping that the experience reported here, that the difference between the GS-X and the GS-1 is significantly more than between the GS-1 and the GLite, will be my experience as well.
I have had a limited time listening to a Beta22 and an Apex Arete/Volcano. I thought both were good, but not quite as transparent as the Gilmore designs mentioned above. Quite frankly, I found them just a bit better than the headphone jack on my Lavry DA-11 DAC. I was unimpressed by the Burson H160. It had more gain than the headphone amp in my DA-11, but at equal volume, I liked the sound from the DA-11 better.
I know there are people who talk about how the beta22 or a good tube amp will be more musical and more forgiving than say the GS-1 or GS-X. After spending a bit of time listening to a couple of good tube amps for the HD80 my conclusion is that if I am listening to a bad recording, no amp will tame the HD800. Crap will sound like crap. Either I need to grit it out until I get to the next recording, or switch to much less detailed headphones or speakers.
I wanted to have control over my system and try to keep things <fairly> reasonable. I'm feeling good right now after a lot of effort and work by others too (other HD800 owners and modders and amp tuners and experimenters).
With the Inner Fidelity foam mod and no dust covers, it is a more balanced phone for me. I am keeping my revealing source DAC1 because so far (and for the used price I paid), it offers plenty of detail (many think "too much" or too much treble) but I have no veil and the added benefit of two clean headphone outs for comparing 2 sets of phones or quickly A/Bing what difference an amp makes to the DAC sound.
Super 7: After spending some time with different tube combos in the output (6 x 6SN7) and the driver slot (1 x 6SN7), I've been able to use either a 7N7 with adapter in the driver position or Rogers tubes in the output position to soften the top of "bad recordings" and increase bass or in the case of the 7N7...also increase the stage.
In fact, I went a bit <too> far in making the HD800 bassy and lost some resolution too- so now I am bringing it back to find the right balance and have some combos I already like a lot. Next, I'll try some capacitors that Anaxilus has been experimenting with. With the price of the Super 7 (I did get pre-order), I feel fine about the $ spent on tubes and now some pricier capacitors.
At the last mini-meet, I purposely left a bassier/less-resolving set in to show the HD800 range.
With the B22 I am borrowing right now from particleman14, I like the way it handles the sub-bass (touch bigger, but still tight) and it seems to have the extension up top but a touch less mid...just slightly further back in the presentation. EDIT: I do see how @verber could say the B22 isn't much different than the DA11 headphone outs. I hear some differences from DAC1 headphone outs but they are subtle... Also, I liked the DA11 low bass better than the DAC1 during the very short I compared them, as well as the PiC controls. Prefer the Super 7 and flexibility to the B22 with HD800 and my source.
If you have a Peak/Volcano, try a 7N7 with an adapter in it. Cheap and makes the stage bigger + softens the bright/edgy recordings. I really like the Peak and it's easy to tell what the tube is doing, especially if you have a headphone out on your DAC for faster A/B to a reference.
Oh, I tried the new PS Audio NWD and it is a touch "warmer" or more "musical". But, I've already done things to make my HD800 sweeter so I didn't need this DAC change. (Some will like it in brighter chains, I imagine.)
EDIT: Oh, you'll notice the Gilmore Lite in the picture under the iPure Dock (for easy iDevice digital-out). I liked the Gilmore Lite to take a <very slight> edge off of the DAC1 before I got my main amp. Nice little desktop unit, not a lot of change to sound (to me).
Edited by CEE TEE - 12/1/12 at 1:05pm