Part of a short-lived line of EHX pedals using this style and size of foot control. There were also a wah, fuzz-wah, envelope filter, sub-octave, the HotFoot expression pedals, and (of course) volume. This pedal is in excellent condition and all parts are present. The Bad Stone was EHX's first phaser, coming close on the heels of the successful PS-1A from Maestro (the original phase pedal). This Bad Stone is a 6-stage phaser using a CD4009 chip for the effect. A super smooth phasing effect, very lush and a nice range of depths. There are controls on the sides for Speed and Depth, and an interesting toggle on the side that flips on a pitch-bendy vibrato effect (I am guessing it cuts out the feedback loop). The forward footswitch on the right is the effect on/off switch, and the one on the left (officially Auto/Manual) engages the treadle which lets you control the phase speed with your foot. As you can see, a previous owner marked what everything does as the original had fairly fragile paper labels, which are long gone. These are very rare, and this one is all original.