Which One Amp for the Magnepan 3.6's?

I'd also look into the Wyred 4 Sound monoblocks.

For a while, I used a KAV-250A with 1.6QR and thought it was a killer combo in a large dining/living room combo that was 24 x 28. Listening in nearfield, the Krell could drive the 1.6 to very loud levels with trememdous bass, a wide, tall, and very deep soundstage and plenty of detail without hardness. I liked it much better than the A21. I have not heard the JC-1 monos. I imagine it will power the 3.6 well too.
Tim

From the ones you have listed, hands down the JC-1 monos. If you are open to other suggestions, try a the new Sanders MagTech amplifier...

MofiMadness has a great suggestion, I would also say the Parasound JC-1's & Wyred4Sound 1000 monos.

I have tried a ton of amps, including the Parasounds and the excellent Innersounds (now SandersSound) and along with the big Brystons (14bsst or 7bsst's) I think my current amp with the Maggies is just stellar; Cary CAD500 MB's, big current, big sound.

Between the 3 you list, I'd go for the JC-1's (def not the krells
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I agree that the Pass Labs x 350.5s would be an awesome match. I used to use class cam 350's with my 3.6r's - was very happy with that pairing. I like the class even better than the JC 1's. I switched to Lamm M2.2's a few years ago (got a great deal on a used pair) and could not be happier.

Also, second the nod on the mye-stands. They are a HUGE improvement and will do alot of good for not that much of a financial investment.