I'm exhausted beyond the capacity for rational thought, so bear with me here...
I have just done some listening. I compared the H2 driven by my rubbish gear (Denon PRA-1500 pre, Onkyo M-504 160wpc arc welder and Monster cables) sourced from my trusty Rega Planet 2000 to my transportable rig - HD600 driven by the Hornet out of a MicroDAC, 1s and 0s coming from a Sony D-NE920's optical output.
The H2 suffers from an uneven tonal balance. The highs are very crisped and very bright, the midrange seems to be recessed, and the bass seems to be somewhat overblown in the midbass and upper bass region. The HD600 is much more linear, though it doesn't extend as far in the bass or in the highs. However, I should point out that the M-504 is known for its toasty highs and general frequency response nastiness.
The H2 seems to be lacking definition. I would compare listening to the H2 after listening to the HD600 to looking at a focused image, and then getting it out of focus. Everything is just blurred, and sonic images have a lot less definition. This is most evident in the midrange - vocals aren't localized with any kind of accuracy but sort of occupy a formless space at the center of the soundstage. At the same time, the soundstage is much bigger with the H2 than it is with the HD600. This is definitely not good news - if the HD600 is beating you in imaging, you have problems. But, I should also point out that the Onkyo amp is also known for collapsing the soundstage in a recording, and I'm guessing at least some of the imaging problems are caused by this.
The H2 also seems to be lacking in dynamic range. Everything is either uniformly quiet or uniformly loud. It doesn't seem to be strained for power during loud build-ups and swells, but the difference between these build-ups and the quieter moments isn't as pronounced as it is on the HD600 rig. Everything on the HD600 just seems to have more power, and is a lot more vibrant. The presentation is vivid and alive, whereas the H2 seems somewhat squished.
Tone and tembre seem to be handled well by the H2 in this rig, but texture isn't. This gives everything a sort of crystalline quality, quite pretty but also unrealistic. The HD600 is more accurate in this regard.
At the same time, the H2 is definitely the faster transducer, and not by a small margin. This leads me to believe that the veiling/blurring effect that I hear is upstream, and not a product of the transducer itself. It is also more impactful, and much more extended in either direction.
I also hear a rattle in the left driver during bass-heavy passages. I am not a low-volume listener, I like to crank it, and a lot of my music is very bass-heavy. So, if this persists, it will be a deal-breaker for me.
I am hearing a great deal of potential here - if we could just focus the sound a bit more, give the headphones a much clearer and more resolving signal path, give it some more punch and dynamic range, and take care of the FR irregularities, we could have a seriously wonderful sounding rig. Specifically, it seems to me that the H2 should be capable of conveying incredible amounts of spatial information. In fact, with some recordings, even on this rig, it throws a truly incredible 3-d soundstage that is full of depth cues and nearly holographic imaging - but only with a select few recordings. Which, unfortunately, I can't find right now, so I have no clue if the HD600 would do it better.
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In terms of amping - I can't afford the BH at the new $4.5k price tag, so that's out of the question. The most I have for spending on an amp is $2k, and I want to put a K1000 rig together as well (and fast) so realistically it's more like $1k. At this price, I don't think I'm going to get anything stellar, so I might as well wait it out and see what comes of the direct-drive H2 amp project. But in the meanwhile, it would be great to find a nice tube integrated that can power the H2 as well as the K1k decently well. Hence my useless posts here
If only I liked solid state more, I'd have more options.
This looks tempting (Dared MP-15):
That's not an amp, that's just pornography...