I have a ABM1000 & a JJB600 I would say that the JJ head for me has a more clinical sound & I like it more for Foxton ,JJ , Chris Squire & even slap type stuff . With the graphic & huge amount of power I don't cut any middle I boost certain bass & treble frequencies that gets a sound I like & it cuts through live . You can not get these amps to sound like each other ,close but not the same ,