Looking for advice re: amps for Dynaudio Contour 20i

I own Dynaudio Heritage but I have a Contour Ci center. All three being driven by Simaudio M400 mono amps. Outstanding.

This is the two channel version of the 400ms I own. It would be an excellent match. 330A. Class A first five watts..

Check Simaudio website.

Dynaudio need a powerful amp and they sound their best at higher volumes. 
I owned the S5.4 and drove them with Pass Labs X250.5. I also tried Rogue ST100 but the bigger Pass amp was better at opening them up. 

I would put the Parasound halo Jc5 on my short list.

Dynaudio is the US importer of Octave, and for good reason.  The two brands show together and sound incredible together.  Dyns can be a bit harder to drive so you need a black box or super black box with them but the results are going to be very, very good.

Alternatively, Hegel is a good choice with Dyn.  Clean and clear with speakers that are clean and clear.  Good combination. 

My take: You have two challenges to meet to permit your DYNAUDIO’s to max out their potential. I would suggest that you do it in this order

(1) Amplifier power ratings

DYNAUDIO craves high-current amps…. WPC alone are meaningless.
Another word on power: if your speakers are demanding to drive you’ll need a suitably muscular amplifier to support them. Don’t look only at the headline power figure - see what happens when the impedance drops to four ohms. If the number nearly doubles, then your amplifier has good current delivery and will be capable of driving more demanding speakers.

I would stay away from tube amps and stick with refined and beefy solid state options,

(2) System synergy matches

Now, because you have a much shorter list of contenders as you carved out the pretenders, you can now start the auditions and scope out reviews for that ethereal system synergy option tailored with your speakers.

You will get a plethora of amp model suggestions herein as replies to your post. But they have a high element of personal bias pushing their fave. Hopefully this simple matrix assists in assessing their recommendations as a candidate for your ultimate choice.