Accuphase amps pair very well with Dynaudio speakers, and according to my experience are significantly better than the Mcintosh ones. However, whether or not the A-70 has enough power for your C-4 depends on how loud you listen to music and what type of music you listen.
Given the sensitivity of your speakers, my prediction is that you will typically used 2-3 watts. Consequently, the A-70 will break not sweat whatsoever except when playing big-band and large orchestra music. I am saying this because when I listen to large orchestras the meters of my A-65 (the predecessor of A-70) shows variation in the power requirements in the 100-fold and 300-fold interval. My amp does not run out of steam because the sensitivity of my speakers is 105 dB. However, with the C4 (or with most normal speakers for that matter) that will not be possible. The best thing to do is to try the amp in your system.
Good luck and keep us posted!
Paul
Given the sensitivity of your speakers, my prediction is that you will typically used 2-3 watts. Consequently, the A-70 will break not sweat whatsoever except when playing big-band and large orchestra music. I am saying this because when I listen to large orchestras the meters of my A-65 (the predecessor of A-70) shows variation in the power requirements in the 100-fold and 300-fold interval. My amp does not run out of steam because the sensitivity of my speakers is 105 dB. However, with the C4 (or with most normal speakers for that matter) that will not be possible. The best thing to do is to try the amp in your system.
Good luck and keep us posted!
Paul