Class A amplifiers - which are considered the best

I thought the Plinius SA-Reference which claims 2x100W Class A was already quite a big claim, but has anyone seen a Karan S400 which claims to deliver 470W x 2 Class A in an even smaller chassis!

Vitus audio ss101.

The mighty Karans are most certainly up there with the very best if you're into natural sounding SS.

Goergelofif, the Krell KSA 80 and KSA 200 (and their mono counterparts the KMA 160's and KMA 400's) preceded the KSA 250 by a couple of years and were of different design generations.
http://www.krellonline.com/history.html

They still are not anywhere near pure Class A up to their rated outputs, as you think they are.
I built quite a few pure class A amps back in the 80's based around this Nelson Pass circuit
http://www.passdiy.com/pdf/classa_amp.pdf
but expaned out to 100 watts instead of 20 watts. And I can tell you for 100 watts of pure class A, the first one was bigger than your large sized coffee table, and weighed in at 120kg and still it got the heat sinks up to 60c after 3hrs and proceeded to get the dreaded class A thermal runaway, plus I had to change the power points to industrial ones because it started to melt the standard house ones.
The only way to keep it cool was to fan force x 4 the massive heat sinks, but this was too noisy. After this amp I built the same but this time I water cooled it, first one was self contained recirculated water with a quite pump heat sink jacket mini radiator and fan, it looked weird but worked a treat, wish I had photo's of it (still weighed in 60kg. After this one there were 2 more both water cooled but using the house water and draining into the garden.
This unsound is why I am confident in what I say about the pseudo pure class A amps out there, and why you should study the link to the Mark Levinson ML2 mono blocks I posted earlier and see what it takes to get 25w of A class, and they get too hot to touch

Cheers George