Okay - here's a first, I'm answering my own question. To any that care to know, and I certainly did, according to Mike at NAD support, the 390DD has been known to shutdown on loads of less than 4 ohms - and the Maggies do dip below 4 ohms - however slight, and that is according to Wendel Diller at Magnepan. (Yes, I've been busy)
That's a bit of a bummer as that 390DD DAC/amp seems chock full of value.
This should have been much easier, all i wanted was an insanely great amp, at a reasonable price, to go with my girls. I have been researching this for 5 months (I have even returned a few earlier attempts). Then I remembered Jonathan's review of the Odyssey Khartago amp. I noticed that the Odyssey website did not list that their amp doubled its power as the impedance halved, as Magnapan recommends. So I called Odyssey to see what's up.
I talked to Klaus Bunge and that was my first "mistake". Klaus' enthusiasm for what he does is wonderfully infectious. It was a pleasure to talk with him and after a short while I knew I'd found my amp. Klaus and Odyssey are very familiar with Maggie 1.7's and knew exactly what I needed. Needless to say I bought the amp on the spot - which takes 3 weeks to build by hand at an absolutely amazing price. Not only that, but I upgraded the power supply, increased the capacitance, upgraded the board, and added WBT connectors on both the inputs and outputs. I'd tell you the price but I think it's better if you talk with Klaus - and a lot more fun.
Thanks to Jonathan and TAS for bringing this amp to our attention and Klaus for making it happen. It was absolutely (no pun intended) fun to be an audiophile today!!!