Sort of. You have the base stuff in the amp (same chassis layout, power amp, eq, transformer, power supply and wiring) but the preamp is different enough to be more than a tweak or easy rewire. And that's because of the preamp PCB. So to convert, you'll have to either find or make a iic+ preamp PCB, or build the circuit up by hacking up the iib PCB. Either are possible but not necessarily easily implemented.