Mine just arrived yesterday, although I wasn't able to sit down and listen until today. Sadly, I discovered that the reterm'd 4-pin cable I had bought was done by a hack, so I'm limited to SE listening on my Senn 650's for the time being (although I'm using a balanced signal out of my DAC_1), until I make a proper cable.
Shipping time: Quick, with David sending multiple notifications during final testing and shipping. $12 in mystery fees at the door, but that's par for the course. Everything well-packaged, not a scratch or blem to be seen. But this is my third order from Little Dot now - I'm not surprised at all.
Out of the box: Also good. Only came with a basic pair of L/R cables, so it's a good thing I already had some XLR's to hook up to the DAC_1. It came with a blue LED, instead of the requested red, but meh. I may swap it out at a later date if I'm feeling picky. An English instruction manual (it did include what I presume is a Chinese one) would have been nice as well, if only to confirm what the default gain setting was (from the volume and volume dial setting, my money is on 4).
Quick listening impressions:
Setup: PC > toslink > LD DAC_1 > LD MkVII+ > Senn 650 (SE for now)
Old Setup: Same as above, except with LD MkIV
Music: 10 hour marathon of live Dream Theatre albums
As best I can describe it, the MkVII+'s sound is more detailed, and definitely with more low-end extension in the bass. Not necessarily more (although maybe slightly), but I almost immediately noticed that the bass didn't try to fade at the very lowest frequencies. Not that the MkIV was ever bad, but I've heard that OTL amps have this tendency, and I think I may be getting a comparative demonstration of this now. It's something that I definitely expect to appreciate for a long time to come. Other parts like the cymbals and high-hats are clean and distinct, and background details like crowd voices or guitar string scratching are there for the hearing, moreso than before. No flaws or imbalances in any frequency range, although I intend to put it through a gauntlet of jazz and electronic trance stuff as well.
While it obviously doesn't have the tube signature of the MkIV, the sound is by no means sterile, still plenty warm for my liking, and meshes well with the 650's. Ten hours of straight listening (okay, maybe a bathroom break or two), and I was experiencing no fatigue or ear strain.
Since the MkVII+ is rated at a lower 300ohm output power(300mW) than the MkIV(500mW), I was a little curious whether that would become an issue. Not that I can see so far, as I can crank the volume up well past my comfort levels without encountering any clipping or distortion. Since I'm almost certainly giving up some voltage swing running SE, I'll see if anything changes once I get the phones balanced.
At this point, I'm definitely looking forwards to trying everything out in full-balanced, but I have no complaints with how things are now. Very definite improvements to to the sound, and this gives up very little to the MkIV, unless you're hardcore into the tube sound signature. No scouring Ebay for affordable replacement tubes, no trying to position the amp so there's a little bit of airflow past it. Much more listening in the days to come with different genres, with both amps, but if things keep going the way they are, there may even be a used MkIV showing up in the FS thread in the future. Although I'd miss the glow
My 2c