Hi -I bought a used SVT 3 Pro and it did not have the original footswitch. I bought a generic footswicth thinking it would work but it does not. I'm not sure if the switch i bought is defective. I bought it new. Should a generic footswitch work for this amp or do i need to get one from ampeg? thanks erik ps - does anyone use this amp with another power amp to get more power? how are the results?