Well, I bought a used RM4 off a forum member, and I finally got a MIDI cable to go with the ADA MPC footcontroller he threw in for free, and the thing needs an external adapter and no 9V's fit the freaking plug, and since ADA is out of business, I guess I need to order the Randall footswitch. I noticed that the Randall footswitch has a power supply plug on the back; does this footswitch need a power supply to work or will a 7-pin MIDI cable power it?