ATC SCM40

@lonemountain can help you with ATCs. I heard one over the weekend at a dealer, and it sounded as I expected, very pleasant, detailed, neutral. 

We are an Atc dealer with both the active and passive versions on display,

and in our past worked at a store which sold the 2ci

So yes the scm 4os are a large step up however the adcom amplifier might be a bit too forward

Dave and Troy

audio intellect NJ

Atc dealer

I love my ATC SCM19v2.

Run them with a 200w per channel Perreaux R200i.

I recently posted my experience auditioning the active version of these speakers and loved them.  John Rutan at Audio Connection in Verona, NJ has both the active and passive versions on the floor.  I think the actives sound much better, but they are also about $5k more.  Of course, you could then sell your amp.

I owned SCM40 passive speakers for a while and then upgraded to the SCM50ASLT active speakers. Like many others, I prefer active ATC speakers.

After trying a number of tube and solid state amps with the 40s, I found the Coda Continuum No 8 stereo amp to sound the best in my room to my ears. Manley Snapper mono blocks also sounded very good.

At the Arizona Audio Video Club Speaker Fest in 2019, ATC SCM40 passive speakers with ATC electronics won by a wide margin against seven other well regarded speakers.

Sorry, I have no experience with the OP's Adcom amp.