Uploaded April 2011 | Updated September 2026, 3 weeks ago

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hackaday.com/2011/04/03/adjustable-prank-box-growls-and-screams
Basic astable 555 circuit: electronics-tutorials.ws/waveforms/555_oscillator.html (the part on the right) ... and you have to add some feedback from the output to the CV pin 5 with a variable potentiometer. Sorry my backup drive is down so I can't access the original schematic.