Hi, It is true that a ST 70 will drive Magnepans. I used my modified ST 70 to drive a pair of MG12's. It did a pretty good job driving them but I wanted more bass control and I ended up with a Moscode 300 hybrid amp mainly because I wanted tighter bass.
I added two Dali 12" acoustic suspension subs and I had a crossover made based on the impedeance of my ST 70 and the Maggies started to roll off around 50Hz and the subs took over from there This solved the bass bloat problems. The MG12's blended very well with the subs and they had pretty good dynamics too. Of course I used the 4 ohm tap and I would not try that in a larger room. If you want to rock no way will the Dyna do the job without clipping.
I added two Dali 12" acoustic suspension subs and I had a crossover made based on the impedeance of my ST 70 and the Maggies started to roll off around 50Hz and the subs took over from there This solved the bass bloat problems. The MG12's blended very well with the subs and they had pretty good dynamics too. Of course I used the 4 ohm tap and I would not try that in a larger room. If you want to rock no way will the Dyna do the job without clipping.