I ordered a Schiit Asgard 2. I'm sure there are better options, but probably not for the price. I had the original Asgard on a couple different occasions in the past, and I liked how it paired with the K701 -- so I figured it would be a pretty safe, low-cost option for the K702.65 as well. If there was an easy way to take the K702.65 balanced while keeping a single-sided entry, I probably would have gone for the Bryston BHA-1 instead. I heard that amp with a balanced K701 at CanJam and was very impressed.
And I agree regarding the DT880 and T1 -- with these headphones, there's a lot of sssss going on, whereas the K702.65 doesn't have this problem. I can get used to the extra sssss pretty easily though, so it doesn't bother me too much with the DT880. I personally really liked the T1's spatial presentation -- the soundstage sounded "spherical" in shape to me, with roughly equal width and depth, and a good size. Imaging on the T1 was really sharp too. The DT880 is a bit "flat" or "2D" by comparison. The K702.65, by comparison, has a wider soundstage than either of the Beyer headphones, and I think it has more depth than the DT880 but less than the T1.