which of you uses JADIS Amp with Magnepan 3.6R ?

Not likely enough juice for 3.6's to get adequate dynamics
and bass. I'm a believer that the larger Magnepans need
AT LEAST 300 W/Chan @ 4 ohms to do justice to these speakers.
Many complaints that Maggies "lack dynamics" or
have "no bass" can be traced to inappropriate amplification.

As above. IF you really want to use those Jadis, you'll be better off changing spkrs (or seriously modding the xover with uncertain results). BTW, I love Jadis, but the Plinius you already have is a very good amp.
Cheers!