(This is a synopsis of my letter to Frank Van Alstine after receiving and listening to my recently acquired U70.)
I received my new U70 last Thursday, took my other 70i out (I had 2 70i's) and plugged this one in. I wanted to let you know that everything written in your ads about the new design is true. I thought you might be interested in what I heard. (Keeping in mind that I use the amp for tweeters of my Magnaplanars from about 500 Hz up.)
The old 70i was reasonably transparent, sweet and I loved it, particularly the midrange. If it had a characteristic sound at all, it was one of minor omissions (particularly at the high end), and a slightly congested sound as the music became louder and more complex. There were times that as the music became very it sounded that the amp may have been clipping. The new amp has no sound of its own at all, at least at the levels at which I'm listening. The highs are much more extended and natural, but don't draw attention to themselves (as they shouldn't.) When the music gets louder and more complex, the amp hangs in there and retains all of its detail and clarity. I don't hear any higher distortion levels as the music gets louder. Lyrics are more intelligible. There is more of the sound of the original acoustic environment is present both at high and low levels. Transients are very controlled and I hear the music "behind" them more than I did with the other amp. There is much less "masking" of the source components and material.
I'll be upgrading my second amp shortly and eventually will run both in mono with a bridge on my (currently bi-amped) Maggies full range.