ATC active vs. passive

I have passive 40s V2, driven by an older solid state Musical Fidelity amp. When I got a streamer and a DAC with warmth—in both cases—everything became a little bit tubier. I’m very happy with my system now. You can definitely warm up solid state power with your source and your DAC.

ATC 40A was my first active speaker, 3 years ownership.  Dynamic, fast attack, nice imaging.  Could be an end game transducer.  It's that good.  Moved to ATC 50A.  It is a very different animal.  More of all that's great about the 40A.  It's quite simply in a different league, as it should be.  My end game transducer.

These benefit greatly from Townshend platforms, Furutech DPS 4.1 power cables  and of course everything done properly upstream.

Have fun

I'm leaning toward 150 passives. Part of this hobby is constantly playing and tweaking with components. 

What tube amp would pair well with ATC?  I'm open to integrated as well. I doubt my current 50 and 100W tube amps will do justice on 150. 

I heard the Mcintosh hybrid amps are too slow for ATC. 

I’ve no experience driving ATC speakers with tube amplification.  However, I abandoned tube preamplifiers as they were simply too slow for the speed of the 40As and 50As.  This happened with my Manley Jumbo Shrimp, Manley 300B and highly modified de Havilland.  I moved to Sugden and Luxman C900u.

Also run passive ATC 20s with SS and 7s.

The 150 is a physical monster.  I hired piano movers for a second story location of my 50s.  Best of luck with the quest.