I don't think they will work well together. I had the A42's, and they were hard to drive. I'm not saying you won't get high SPL with a few watts; you will. But the sound will be lifeless, boring, lacking attack and dynamics. Even if the A42's are the easiest to drive of all Dynaudios, they are still Dynaudios.
I think a punchier amp, such as an NAD 352, will work better. Of course it's also a matter of taste.
I wouldn't mind too much about the slight brightness of the CA amp in this case; I think the Dynas have a soft top end, so the sound shoudn't become harsh.