Magnepan LRS+ which amps do you use ? * 100 watts or less **

No less! More. Try to get a musical fidelity m6 500i or the hegel 360 or 390.

On the lower wattage / lower cost end of the spectrum, take a look at the Audio by Van Alstine SET120 power amp. It’s 60 watts into 8 ohms and doubles to 120 watts into 4 ohms…which is a good indication of the ability to supply current under load. It’s been described as a good match for the LRS by Frank Van Alstine himself after an extended test. It gets warm to hot on the left side where the output transistors are but not overly hot. You can easily keep your hand there. Depending on your room and how loud you’ll play music, it could be all you need.

I ordered the LRS+ about 3 weeks ago myself and spoke with a rep (Eric) at Magnepan about this. I asked if he thought my 30 wpc Luxman 590 AXII would drive them and he said it would. It was made clear to me that it's not the watts, but the current that matters. And a class A that doubles in watts at 4 ohms is the answer. I will report back when I get these because I am very curious myself. 

I received the LRS+ a few months ago for my bedroom/home theater system (for use with a sub) and assumed I would have to get a new amp.  I was pleasantly surprised to find that my old Adcom 545II drives them so well that I don’t even know what I would be looking for in another amp.

I believe the Adcom is rated around 100 watts into 8 and 150 watts into 4 but it was sold as a high current amp.

With those speakers, think voltage or robust & massive power supply; not watts.