Has anyone used the KD-5 along with another kick trigger that is not a KD-5? I recently got an old TD-5 kit and it has a KD-5 trigger. I looked at the literature and it shows this can be hooked up with another KD-5 to give a double bass pedal but it shows that only another KD-5 can be used. the literature doesn't state that there are no other compatible kick triggers-just shows another KD-5?? I think the other one I have is a KD-7. It is the rubber type stand up pad.