Using Adcom GFA-555s as monoblocks to power magnepan 3.3s in active biamp

What sound levels are you hoping to achieve? 

Loud, but I can get there with my current setup and it sounds good. This was just a thought that maybe 800WPC monoblocks would be good to try on the bottom.  But not if they're going to struggle because they're bridged. 

Have you tried the Krell on the Bottom?

Yes, had it there for years and sounded good.  I thought the Classe CA-200 was actually a little better on the bottom with the Krell on top which is what I had for a long time.  I just moved the Classe so thought I'd see what else might sound good there. 

I think the basic point is there's a stability issue into 4 ohms with bridged amps, and if my goal is to be able to pour a lot of current into the bass panels, this isn't the most stable way to do it.

That's fine.  The Nakamichi actually is pretty muscular there.  I may try the vertical biamping idea at some point.  I wonder if the uneven load on the channels in that configuration would be a long term issue?

Personally, I would not do it.  My experience (repairing) with Bridging amplifiers is they become very unstable when powering low impedance speakers and driving them hard.  If a 16 y.o. tells you to "turn it down", I suspect you are driving them hard.  States nominal 4 ohms.  Some speakers dip below the 4 ohms.  Especially on the bottom end.  You will be lucky to just blow fuses.

But hey!  Sacrifices must be made in order to Rock and Roll.   It's only electronic gear.  Not like it is the last pair of amplifiers in existence. With trepidation I would say go for it.  Rock On!   LOL  I just remembered, the last bridge set I blew, I was playing Mahler.  I don't know why I assumed Rock.

No, there's nothing precious about the Adcoms.  I have them mostly as backups or to run stuff I'm testing.  

But yes, mostly rock.  I've been spending more time listening to my (new to me) KEF R11s.

I think I've decided not to bridge the Adcoms. 

I wonder why so many amps are bridgeable when most of the inefficient speakers are 4 ohms anyway. 

Run  some fans.

I had a Krell Ksa250  running B&w 801#3's

Got a Pair of Adcom 565 monos on loan from a steroshop.

Adcoms did very well, Sounding a Bit steely on highs but the lows were neck in neck.

The adcom will pry need to be checked for DC offset and or caps replaced.

Fine amps for the money

Which do y'all think will sound better with KEF R11s:  a single Classe CA-200 or 2 Adcom GFA-555's in vertical passive biamp?