Pure class A is rare, rare, rare, very few amps out there, Accuphase made some really nice ones, big beasty space heaters that made lovely music, Yamaha made a big deal with some but, they were really curcuitry that wasn't class A but a very nice sounding A/B...
Then you have the D's, Hitachi started the wave with their special MosFet's, then the digital guys grab ahold of the energy saving power supplies..etc...etc..
Puah/pull is mainly a tube thing...not always, but mainly
Then ya have the triode/tentrode/petrode crowd, and God forbid the foaming at the mouth SET guys
Accuphase pure class A mono bloc amps are $15,000 each save your pennies