Or, depending on your level of electrical engineering genius, you could download the schematic for your amp, also available somewhere at
www.ampeg.com and construct your own functional equivalent.
I know that on my single-funciton switch Mesa Boogie, should I ever forget or lose the switch, I need only plug a 1/4" cable into the jack and ground the tip to the chassis to activate the feature.
That's pretty simple......maybe you'll have the good fortune of having a simple two-function switch.......maybe.
But only mess with that if you really know your stuff on schematics.
Nate