Bought a pair of Magnepan LRS. Should I buy a Schiit Vidar or Bryston 3B-ST?

Areasonableman,
Those toroids are small value chokes and are probably NOT part of the power supply, though they could be.  More importantly, broken as they are, they will NOT work properly and need to be replaced.  I wouldn't bother with much listening until they are fixed.  To work properly they rely on a continuous toroid iron ring.  If that ring continuity is broken it will not work correctly.  Who knows if it was UPS or some other cause, but GET THEM FIXED!

Aerasonableman,
Don't get suckered into the game of high powered amps. Yes the Maggies do need a high current amp with sufficient power to drive them but just because you have a 100 watt amp does not disqualify them from playing the Maggies. It all depends on your amps power supply. I have Prima Luna Premium Dialogue HP amp rated at 85 watts per channel with KT 120 tubes. This amp has huge output transformers that control the bandwith, so it doesn't matter if you have 100 or 1,000 watts your only going to use probably 5 watts.

To echo what cavy said, maggies want high current capacity but would add wattage sufficient for the room size. When I had a 20x30 room, a modified Hafler DH200 (100W) was "sufficient" but a bigger amp would have been nice. Now in a 12x12 room I have 1W of class  driving the 1.7's "sufficiently", can't even use the Hafler, feels like its "shouting" at me even at normal volumes, looking at 25W class A amp to replace the Hafler.

Sorry that should have said 1W of class A above

I’ve been driving the LRS with a Vidar amp for a few months now and the amp has been excellent. If I really crank the volume the amp may go into protection mode but I have no desire for extreme volume. That’s not what maggies are for. As for sound quality a previous post here which stated that Bryston will "sound better" is nonsense.Vidar sq and Bryston sq are exactly the same. Correctly designed high-quality power amplifiers, when not overdriven, do not vary in sound quality.