you have the worst half stack that crate ever made. i owned one so i know. it should be illegal for them to make that crap. for a solid state high gain amp, those transtube and marshalls are'nt too bad. find a music store that carries them and try them out. the old style crate heads, like the g130c, with a normal size cabinet does'nt sound too bad either but they are pretty notorious for input jacks that need resoldering, which is no big deal. you could find one of those heads for probably under $200.
you should be warned, a.p.l. is a Carvin pimp. I've never played a Carvin amp so I can't comment on their tone but I do know that anytime anyone asks for suggestions on gear, here comes a.p.l. to pimp some Carvin goods. A.P.L, have you tried any other brands?