Adcom GFA 5500 vs. Parasound A21

A21 will definitely be an improvement and not a sideways.
You need to check with real owners of Magnepan users on this forum, who use Parasound amps:

http://www.htguide.com/forum/forumdisplay.php?21-Club-Halo-Parasound

Ewpon
Did you ever get a new amp?   I ask because I'm in the same, basic boat. Bryston BP26 preamp - ADCOM 5500 amp -  Maggie 1.7s.
I just love the way the 5500's MOSFETs deliver music with such an airy, spacious, transparent soundstage.  Unfortunately, nobody wants to work on them anymore and my 5500s are starting to need work more & more often.
One of the amps I'm looking at would be the A-21. Did you buy one or have a chance to give one a good listen?  If so, how do they compare?  I'm not looking for any "upgrade".  I'm looking for a newer version of my 5500s.  ( OK, maybe just a touch more bass would be nice)    😉 

Toolbox have you looked at the current Adcom like the 565se? I'm checking in to them myself. Too bad they are not using mosfet anymore!

toolbox
No, I still have them.. I'm thinking of replacing the 3As with 3.7s first.  Satisfied with the adcom for now..