I need to respond to these posts, because I feel the need to make clear my views on the topics they touched on, in part so that folks understand my, and my system's, capabilities and in part because understanding my views on the HD-800 and its sound signature will help them calibrate (i.e., embrace or ignore, I get paid the same either way...) my opinions when I am reviewing these DACs.
First, let me say that I heard HUGE differences between amps with my LCD-3s when I compared several of those components side by side last summer. Night and day differences. Black and white differences. Shades of gray differences. Multicolored differences. It was extremely easy. I could identify any of the amps, any time, 100% of the tiime. I could even hear the difference between 2 kinds of resistors in different resistor boxes with the same amp -- the TBI Millenia MG3. So the LCD-3s are not the reason why the DACs all sound alike to me. It really is that several of the DACs tested so far sound alike to me, and probably would with any headphones that had reasonably flat frequency response across the audible spectrum, and a decay rate that I would not find harsh and unpleasant, or muddy/boomy.
As to the HD800 and its "detailed" sound. I am going to pick a fight here, but so be it, it's X-mas eve, a perfect time for it. The HD800s have a very unique sound signature. They basically suppress the lowest part of the audible spectrum (for humans anyway), as well as the upper mids-through-low-treble region, along with the highest part of the treble spectrum that humans can hear. The upper bass and low-med mids are thus relatively emphasized, as is a spike in the treble part of the spectrum. What this does is make certain parts of any recording more obvious to the ear, because the other parts of the spectrum are quieter. That doesn't make these headphones more detailed, it just emphasizes whatever information is in those parts of the spectrum that the cans make louder, and de-emphasizes the details in the rest of the spectrum.
The HD800s also have a very fast decay rate, unnaturally fast in my opinion. Every instrument in every recording has a natural decay rate in its reverberation, with variations based on the specific instrument, the way it is played, the room acoustics, etc.. The ideal transducer isn't the one that decays reverb the fastest, it is the one that most accurately re-creates the natural decay rate in the music as originally played. Damping that vibration faster than what is in the original recording is equivalent to muting a trumpet or stopping a string, when that wasn't how that music was played. Yes, muting the trumpet or stopping the string allows you to hear simultaneous notes or subsequent notes more easily, but even as you are hearing them, you are not hearing them accurately -- detail, in this case detail about the actual decay in the reverberation -- has been lost, not revealed.
It might be that there is critically important information for distinguishing amps and DACs in the part of the spectrum emphasized by the HD-800s, and in the parts of the recording revealed when reverb is over-damped, but there is also important information for distinguishing amps and DACs in the other parts of the spectrum, and in that lost reverb, particularly for those of us who like sub-bass and upper mids and want to hear natural reverberation. By suppressing those parts of audio signal, the HD-800s are actually removing detail that some of us would use to help distinguish components.
As a result, in my view, because of their relatively unique response, the HD-800s are actually less useful for determining which DAC is best suited for use with most other cans. Cans that have a relatively flat frequency response compared to the HD-800s (and that would be the majority of them, particularly among high-end cans), and which have a more accurate decay rate (again, I believe that includes my LCD-3s, based on what I hear when I listen to individual instruments played live, particularly acoustic instruments and voices), are likely to be mismatched with any DAC-amp combination optimized for the HD-800's unique signature.
So please, nobody send me any HD800s. I think you can tell from what I've written above that I really don't like the way they sound, at least as I have heard them in my own system and at meets. To me they are harsh and unnatural, particularly in the treble. I have a pair of Koss ESP-950 electrostats that I do kind of like that I will use if I think they will help me make a final determination about which DAC I want to keep. On the other hand, if somebody wants to loan me their Stax SR-007s and a quality electrostat amp I'm willing to take them up on that offer...
Okay, enough ranting.
Have a Merry Christmas everybody, and wish me luck in getting the Gungnir running tonight!