Best Amp for Quad 989's?

I'm a recent owner of Quad 989's. I have them paired with a YBA Passion integrated @100wpc. It sounds very good, but compared to what??? I'd like to hear some recommendations on matching amps to these speakers. Tube or solid state could work. I heard them at CES with the Quad tubes and wasn't overwhelmed. It could've been the setup. Let me hear your thoughts?