The ext. amp works great with my amp, the new Orange Rocker 15 (so I assume the Rocker 30 works too). I use a mono cable and set the footswitch "Select" to 1(tip). You have to set the amp's channel select to Dirty (not Natural) channel, or it doesn't work. Unfortunately, the footswitch light ring lights up for the Natural channel instead of the Dirty channel. I wish I could switch the polarity of the light ring.