everything sounded great until the upgrade

I can't speak about the A300 but I have two friends with A3.2s, one with Maggie 1.6s and the other with Martin Logan Requests. I spent a lot of time listening and improving those systems. Both were in very good rooms and both sounded very good. I think the A3.2 can play well with some proper set-up. Give it time and good speaker placement. 

If you have changed the balance of your system, you can try to compensate by doing simple things, like experimenting with speaker or listening chair placement, minor acoustic treatment, like putting tapestries on the walls or using an area rug on the floor (things that may not cost much or unduly disrupt your life).  Doing more to compensate, like buying different cables is a gamble because it may not work.  I hope it is something like changing the toe-in of the speakers that will do the trick.

sometimes just getting familiar with the new sound will also change your mind, so be patient and go slow with the changes.

I can understand your not wanting to fully disclose the products involved, but perhaps you can say what were the components that you liked before the change.

I don't have a lot of placement options but I will do my best :)

I don't doubt it's a good amp.

@larryi 

it's all in the comments now, Marantz 2252B --> Musical Fidelity A3.2

Dynaudio Evoke 20

My initial hope was that things would get better not worse, So the improvements you are suggesting (all great ones) are "me working for the amp and not the amp working for me" :) if it makes sense. But I will get up my butt and play with the placement. 

   I   loved the sound of my modest system, until I upgraded my amp. 

It seems you answered your own question - trust your ears and first impressions.

Take it from someone who has gone down the rabbit hole of trying to accommodate the one thing about my system that didn’t sound great to me.  In my case it was a pair of large speakers that many said were great-sounding speakers.  After about 3 years and too much money I finally replaced them - problem solved.  In the end, the simple solution was best.