Help with drum machine schematic

Hi, I saw this webpage which has the circuit for a drum machine explained: Anatomy of a Drum Machine | Mickey Delp dot com

I was wondering, once I do the circuit for a "snare drum" (SD) for example, where should the Arduino output pin be connected? To the termination where it says SD maybe?
And what type of output should it use? Just sending a digital "1" on the Arduino pin to the snare circuit make it sound?


Yes - note that these labelled control signals connect to the PIC controller in that circuit (second page of the PDF) and are logic level. The 9V supply is split in half by the TLE2426 to give +4.5V for the logic AFAICT. Note that the TLE2426 only provides up to 20mA so might not be up to powering a whole Arduino board.

It isn't a great idea to use a "Rail Splitter" as a primary current source as the Rail Splitter is a reference voltage and not a current source in the classical sense (I.E. Power Supply). It's kinda like using a steel ruler for pounding nails.


oh, so can I take the 5V from the arduino board and maybe put a resistor somewhere in there in order to get the voltage down to 4,5V... or something like that? :stuck_out_tongue:
Sorry, I am a begginer about circuits.

You could try powering it with +/- 5V rails. The Arduino will take more current from +4.5V than the splitter chip can provide I think.

Alternatively power Arduino separately, the 0.5V difference shouldn't matter because the circuits controlled have resistors that will limit the current, some have diodes as well which will lose 0.6V or so anyway.

It ought to be possible to redesign the circuit using rail-to-rail opamps to just run off 0..5V, but that's a lot more ambitious.