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.