I don't have clip but I'm a bit familiar with the amp since its similar to my Studio .22 plus.
I know when you footswitch to the distortion channel, it kick in another preamp tube (cascading gain). What the major different between S.O.B and a Mark II is that you don't have a preamp volume control for the preamp gain on the distortion channel. And like I mentioned on the other post, its like a Mark III's rhythm channel only. A Mark III has two modes on this rhythm channel and its footswitchable.
Does it include a 5-band EQ graphic?