There has been some talk over on Vdrums.com & eDrumming.com about triggering an electronic drum module with a DC voltage. The I have achieved this, and the video below shows how. I also included a schematic of how this test could be expanded. I have not tried this with an Alesis or a Roland drum module, but I will be conducting tests with my Roland TD-8 soon. (You will need QuickTime Player to view the movie.)

DC voltage test movie

schematic

Edit (9/10/08):

I never added the picture of my concept switch bank. Here’s the picture that I did for it: