I thought that I had those dimensions already worked out a number of years ago, but I can't find them at the moment. If memory serves me, though, I'd expect there to be more than an inch of offset between each corner and the associated foot. That means for a 17.2" wide x 18" deep amp, you're probably looking at about 17" or slightly farther from front face to the back feet. This should hold true for all of their multichannel 200W amps (7200, 7500, 7700). The 7900 is about 1.5" deeper than these, the 7125 is almost 1" shallower (16.2" instead of 18"), and the 7075 is 2.5" shallower (15.5" instead of 18").