Exactly,if I could crank my amp I would just buy a plexi and peg it and smile till the end of time.But playing clubs my Marshall on 4 is max for the PA system without having to bring the band up around me to a volume were people can't enjoy it.Hell the loudest I've ever giged my amp was on 6.Don't forget slash is playing in auditoriums for 1000+ people not in a bar for 150 or less,not to mention on those bad nights were you only got 30 people in the bar theres no bodies to soak up the sound then I'm really screwed(OK maybe not just loud lol).
Anyway I'll look into the Ampeg thing,I've thought about trying old Orange heads too.I've evan thought about amp mods.I'd like to have one of the gain stages on a toggle switch or on its own seperate control pot,for if I ever want the added distorion.Basically the head I've got is the Factory hotrod version of the JCM800 2204 its got the mods that players used to add to there heads,added gain stage(4 12ax7s instead of 3),line outs,FX loop and a switchable volume boost.Its got the Drake transformers and factory EL34s(not 5881 conversion).