While the KST-100 is not a 'pure' class A design, at the level you are running it the amp should maintain class A operation.
Do I esentially have a class A amp?
I have a Krell KST 100 which has class A/B topology but it runs in class A up to 50 watts or half power before sliding over to class B. At most I may use 10 watts and at that very rarely when I drive my Vandersteens. So my question is do I essentially have a class A amp?