Magnepan 3a's with two bridged krell 1000wpc 8ohms

It will work fine. I would say to be a little careful as you may start to pop the fuses in the Maggie if you push too far.

I found with the older Magnepans that more power usually meant more volume before the bass panel started to rattle and hit the magnets. But you will reach the poor old maggies volume limit quickly.

I would say the Bel cantos are perfect for them. 1000 clean watts. I had 3.6rs never blew a fuse. Just made them rattle a few times