Which One Amp for the Magnepan 3.6's?

Have read about the Pass Labs X-350.5; looks very good but perhaps out of the immediate price range...

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.