I have Dynaudio Contour 1.8 and I heard these speakers with McCormack DNA-225 in a store. My jaw dropped to the floor.
The DNA-125 should be plenty enough power to drive the 1.3SE's as long as the room is not huge. On a medium to small size room you should be fine. The DNA-125 sounds very much like the DNA-225 with a little less ooomph. In both, you will get a soundstage that is wide and deep and well defined. The Dyn's also excel in the soundstaging dept. as well, and the combo with DNA is intoxicating. Unless you listen to music super loud and/or your room is gigantic, I think you will be very happy with the DNA-125. I suggest you see if you can borrow the demo and try it for yourself.
The DNA-125 should be plenty enough power to drive the 1.3SE's as long as the room is not huge. On a medium to small size room you should be fine. The DNA-125 sounds very much like the DNA-225 with a little less ooomph. In both, you will get a soundstage that is wide and deep and well defined. The Dyn's also excel in the soundstaging dept. as well, and the combo with DNA is intoxicating. Unless you listen to music super loud and/or your room is gigantic, I think you will be very happy with the DNA-125. I suggest you see if you can borrow the demo and try it for yourself.