Looking for advice re: amps for Dynaudio Contour 20i

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.

Thanks everyone! I appreciate the advice. akg_ca, last night I was thinking along the lines that you laid out - sort of like high torque / low revs vs. low torque / high rev horsepower; e.g., a 6 cylinder and 8 cylinder with equal power will never feel the same. I just don't know how to read amplifier specs to identify whether an amp is high current. 

I spoke with a salesperson who advised me that if I was unhappy with the sound, it had to be my speakers rather than the Marantz gear. Needless to say, I found myself struggling to give any of his opinions any credibility.

I 2nd an Octave integrated. Heard one in the C60 and it was really good. on paper probably shouldn’t work that well but sounds fantastic.

I have personally used a Cayin A100T on a pair of Focus 140 and it was not very good sounded really bland. An Odyssey Stratos plus in the same speakers was really good. 

Also have had a Lyngdorf 2170 on some C20s and it ran out of gas. It was fantastic on more efficient speakers. 
 

+1 pass labs

Just above your price is the Musical Fidelity Nu-Vista 600 the 800 would be a few grand more.

https://tmraudio.com/components/integrated-amplifiers/musical-fidelity-nu-vista-600-stereo-integrated-amplifier-silver-open-box-1/

TMR also have the M8XI

Musical Fidelity and Dynaudio have synergy.