Ok, this isn't a review as such - I've already posted about my Solo ULDE - but I had to mention this.
I happened to be in the rare position of being in a town with a "proper" Hi-Fi dealer today. I saw they had the Sennheiser HD700 in and was curious as to how they sound compared with the HD800 (which I own), the thinking being that they may suit my secondary turntable system.
I was left in a room to play, with the HD700, HD800 and a Sennheiser HDVA 600 (or was it an 800 - not sure). Anyway, the HDVA 600 is twice the price of the Solo ULDE so I expected to hear a difference.
Let's get the HD800 vs. HD700 comparison over first. I love the HD800 and can't imagine that a more sublime, revealing headphone could possibly exist. The HD700, in comparison, is very, very nice but different. It is not a HD800-lite, but rather has its own sound signature that is a little warmer, less expansive and closer (for want of a better word). Some of this is to be expected at £400 less than the HD800 but the HD700 is voiced differently. I liked it. I could swap between the two and appreciate both for their strengths. I will quite possibly end up getting the HD700 because it's superb in its own right and it's only the existence of the HD800 that shows up any weakness to me. At its price point, I think it's what I'm after.
Now, once I'd established that I began to notice the amp itself. Listening through the familiar HD800s to familiar tracks that I own (which happened to be coming from a Naim streamer in the shop) I felt that it sounded good. But not *that* good. Not twice-the-price-of-my-Solo good. In fact, I absolutely prefer my Solo. I was left with a fairly smug feeling that my little Solo audibly trounces this rather large, but impressive-looking headphone amp. Sure, if someone gave me one I'd take it, because it's nice, but remember it's twice the price of the Solo ULDE. And that's the 600 - it may have been the 800 which would be more. I still vividly remember the feeling I had when I first got my Solo, which was sheer aural bliss. It made me laugh out loud because it was so good. I don't wish to damn the Sennheiser because it is very good indeed but, at half the price, my Solo ULDE sounds better IMHO.