Unless there has been a drastic change to the questyle in the last year and a half or so since I stopped paying attention to it, it isn't a current mode amp in the same way the bakoon is. The bakoon uses current mode output, the questyle just uses current gain, it uses a standard voltage output.

You are correct.  The Questyle uses current controlled signal amplification, but with conventional voltage I/O so as to maximize the amp's interconnect compatibility with the bulk of 3rd party audio gear, according to them.  The Bakoon has both current and voltage controlled outputs, with the preponderance of use with the current mode I/O, the so-called SATRI current interconnects, much like the Krell CAST interconnect system.

But the Bakoon amp amplification is also 'SATRI' circuitry, employing no negative feedback and current controlled signal, according to a Akira Nagai interview, so in any event, it utilizes a unique topology.

Current controlled signal amplification ostensibly yields industry best minimum TIMD, as well as clarity, resolution and rapid transient response, while current controlled output eliminates impedance imbalance distortion in the transmitted signal.   

Hands and Anax: How's Teton vs ZD Super  ?

I couldn't say directly because there was no ZDS there and a lot of the gear and tube selection was unfamiliar to me with the Teton. All I can say is they are both good amps, but that's about it. Both have a good sense of clarity. As far as resolution, soundstage, dynamics, I can't say for sure. Based on price, I certainly didn't "feel" the ZDS as configured at Wikia was inferior or would get crushed or "lose" out to the Teton.

Can't say I'd refute that. Luxman sounds pretty boring and flat (dynamically) sounding too, a little too warm and unresolved for my tastes. It does essentially remind me of a slightly better sounding Violectric v200.

Where we disagree is whether they sound good. The HD800 deserves better but whatever floats your boat.

Is there something in the HD800 you like you can't find in another headphone?

Had the Bottlehead Crack & if I get the Matrix-M Stage, Valhalla 2 or Vali, I feel that would just be a side-grading & not a true upgrade from the Crack.

On the amps I researched for maybe the past month+ for my $1,200-ish budget, reading through hundreds of pages from dozens of review, impression & comparison threads, I narrowed it down to:

Tube amps:

DNA Sonnett 2, no one has anything bad to say about this, other than that there are better/more expensive amps available. If I see it in the classified again, I might pull the trigger.

EC Super 7, the go to amp for the HD800 under $2,000(?), but I couldn't even find proof that it was put up for sale by anyone in the past 3 years. Not getting this, unless I want to wait it out a long time.

WooAudio WA2, tube-ish sound, warm & smooth, sounds like a tube version of the V200 & apparently has the same weaknesses. I did read from someone that they actual have very different sound signature (was not reiterated further).

Decware CSP2+ & CSP3, highly regarded, but I couldn't find any concrete comparisons with other tube amps or with the HD800.


Solid State Amps:

Auralic Taurus MKII, overall had nothing bad said about it. Seemingly better than the Luxman P-1u & the other solid state amps minus the Black Widow (no comparisons were ever made).

EC Black Widow, one person here vouched for it & was very enthusiastic about it. The only critical comment I found about it vs any other higher end solid state amps was from the Innerfidelity Big Sound shoot out. One of the contestants said the BW made the HD800 sound constricted.

Luxman P1u, besides lacking the transparency & speed of more newer amps, it has been showered with praise from every read. I liked the comments that it does bring out the bass & midrange on the HD800. Though I'm not exactly 100% sure how big of a jump it really is versus the under $1,000 budget amps.

Sennhesier HDVD600, Purrin/Marvey liked it, but impressions from other people said it lacked musicality, being too neutral, lacked bass.

GS-X Mk2, one of the best reviewed amps, but a few people said it being on the bright & analytical side. Not something I'm looking to pair with the HD800.

Violectric V200,  described as having a small closed in soundstage, overtly colored sound, smeared details. At the same time it was mentioned as being neutral, really bringing out the bass/mids & taming any perceived brightness.

I will vouch for the BW but want to know why the ZD Super is not getting the attention it truly deserves.