Vintage Simmons Drums (UK) Users Group

Hello Haley,
the selector pad is nothing but 16 contactswitches and a wired x/y-matrix. Wiring is (measured at the plugs pins): Pin 4,3,1,2 is matrix y and 7,6,5,8 matrix x direction. If you connect for example pin 4 and pin 7, SDS7 will switch to prg 1, pins 2 and 8 will result in prg 16. Pins 9 and 10 are chassis ground only. The selectors plug is not very special, it is a standart video camera plug.

There are no triggers like piezos inside and as far as I know, the SDS7 doesn't respond to trigger signals on the selector socket.
 
Most of the problems with selector pads are shortcuts. The original switches are made of plastic foil material with some conductive material on one side, and the plastic wears out (after more than 20 years...). To find out, where shortcuts occur, you have to measure the resistance between the pins of the plug. If nothing is pressed on selectors top, there must be no contact between any of the 8 matrix pins.

Some guys built their own selector pads, it is possible with nearly every kind of momentary contact switches and a lot easier than repairing the original.
Good luck.
Michael 
 

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