This allows you to control the channel switching on any amp via your midi controller. I used it with a Behringer FCB1010 with no problems. Dead easy to program. See that website link for a complete description.
Anyways, $50 firm and it comes with the AC adapter (and I think a cable to switch a peavey Ultra plus but I can't confirm and its up to you to decide if you want to try it lolol)