Magnepan 1.7 i - Amp suggestions

Agree that you should avoid anything Class D unless you can audition it first. None are good enough to gamble on anyway. The best ones merely match a decent class AB amp. 

The Halo Integrated is a decent match for the 1.7s but a Yamaha A-S2100 would be better. It produces less RMS wattage but has a much larger power supply, which is what really matters when it comes to Maggies. The same reason  why the poster above got better results with a Prima Luna over the Rogue Pharaoh - it's all about the power supply. 

Regarding the Van Alstine 400R--tried that with the 1.7's years ago and sent it back. On paper it looked to be a great match but in listening, I way preferred a Marantz integrated! Was never able to relax and let the music wash over me in a way the less expensive Marantz did.

Interesting. I almost bought the 400R for my .7s but instead opted for Exposure 3010S2 monoblocks. I too was able to get very decent sound from a mid-tier integrated but the Exposures are a nice upgrade with plenty of drive. 

I am surprised by your results though, as Van Alstine is a big proponent of robust power supplies.