Recommendation for ATC SCM150 Amp/Pre

The Bryston 14B3 is worth a look. 

@dynamiclinearity I spent hours with the active SCM40’s and passive SCM40’s; The active system used the ATC top preamp/ controller. The passive setup used a Moon 641 integrated amp; same DAC as source and same room, same speaker locations. I preferred the passive setup. Sounded better to me. It’s not always the case that active is the obvious choice. YMMV of course. 

I might add that the last speakers Gordon Holt, the founder of Stereophile bought for himself were active ATC 50s, basically an ATC 150 with a smaller woofer(same mid range, tweeters and amps). And he told me they were one of the very, very few speakers that made the live tapes(and he did many of them including large symphonies, etc.) he made sound the like the live performance he heard while recording. If it's accuracy that is desired rather than 'musicality' then powered ATCs are one of the few routes there.

@dynamiclinearityin audio, there are no absolutes. Just preferences. No matter what ATC speakers (or any other brand) discerning audio enthusiasts end up with it’s all good 😊! Besides all that , the OP clearly is interested in amplifiers for HIS new passive ATC speakers. I doubt he started this thread to have a conversation about ATC passives vs actives. If so OP, please correct me if I’m wrong.

There's a lot of truth in what you say but there's too much 'sounds good to me' in audio which is ultimately fine for each individual but there are products that do allow suppression of belief on great recordings and there's almost universal agreement active ATCs are superior to passive ones.

I have never experienced passive ATC40s(which will vary from amplifier to amplifier) but I lived with a pair about 8 years ago for over a month and they were special.