Have both Spectron and Classe CA400 before, Classe is veil like Michael said and you can tell right away it's a solid state trying to be tube by sounding overly smooth and veil. In another word, failure attempt to mimic tube, at least that's what I heard in my system.
Spectron on the other hand is very good. it's not tube, but it has pristine and very transparent top end.
Spectron on the other hand is very good. it's not tube, but it has pristine and very transparent top end.