Class A Solid State Sound

I have a re-capped Krell KSA-200S and was wondering if it was bi-polar?


I also have a Krell KSA-250 (OLDER MODEL) & was wondering if that had bi-polar transistors (I think it does).

I like the sound of the old Krells, but some say that some of the newer amp designs are better. I need stability to 1 ohm (Martin Logan ESLs).

I had KMA 100s. Old Krells are all Bipolar output stages. Wonderful amps until one blew.

Accuphase class A amps are stable into one ohm load. 

 I’ve heard diverse opinions on “pure” (non-bridged) class A monoblock amplifiers (Such as Antileon Evo Monoblocks and others) vs bridged class A Monoblocks (like Clayton M300 bridged internally by the designer or Luxman A600 in BTL mode (bridge tied load) 
Many feel the non bridged Monoblocks are better sounding, when output devices from the two channels are summed in Parallel vs Bridging the two channels.  Thoughts or technical explanations?