the phrase 'class a' gets tossed around a lot with no regard to the technical meaning. people seem to think it means 'grade a' or something. i guess manufacterers going on about the wonders of their 'class a' circuits all the time could make you start to think that class a = "must be better"
truth is i dont think ive even seen a tube preamp that was NOT class-a. even push-pull tube preamps are always biased class-a as far as i have ever seen. you dont see the other classes start to enter the picture until you get into amps that have to deliver some power.
so yes the g9 is class a.
the sebatron might be a fine unit but i couldnt ever buy one because i will always associate that name with r*cording.org
its hard not to when that stupid banner ad was staring you in the face on every page on that site!