I went to an event at the SAE Institute in Stockholm where a fella by the name of Daniel Pettersson showed how to make a simple square wave synth with help of a hex inverter chip.
I read a Hackaday instruction recommended by Daniel and ordered a couple of hex inverters and some capacitors and got cracking on my breadboarding. Unfortunately the sound files from the project page were missing so I had no way of knowing if I was really doing it right.
I ended up soldering everything to a prefboard and putting it into a Thunder Honey jar. That’s when I should have called it quits. Originally the design only had three potentiometers for modulating the square wave but I kept adding stuff; an on/off switch and a power LED. So far so good. Then, probably the most fatal decision, I added a trigger and a cutoff button. The black button triggers the square wave. The red button cuts the tone when it’s playing. This would probably have been nice if the quality of the buttons weren’t so bad. The red button works semi frequently… at best. The last feature added was the volume knob. I thought I could simply fade from full volume to silent with a potentiometer but apparently not. I did not solve any of the more complex methods this time so I’m stuck with a volume knob that goes from full to… well, a little bit quieter.
Mounting all the controls in a twist off lid was not the best idea. Even if the cords are long enough, it still puts unnecessary strain on the solders. The 3,5 mm audio jack is mounted on the side of the jar and the 9v battery rests at the bottom of the jar. Even a box with a snap off lid would have been better. And I would have preferred to access the battery through it’s own lid or I should have added a DC jack for external power. So there are improvements to be done but I think this project will have to rest for a while so I can focus on other exciting projects.
Minus minus equals plus. The Thunder Honey synth & the Dela-la-lay effect pedal.