Yup. I had to giggle when I looked at that Modwiggler link you found. I was imagining something with three or four op amps but if the schematic there is correct then it's really cheap and dirty stuff.Steve W wrote: ↑Sun Nov 26, 2023 10:46 pm Could starving a CMOS chip attempting to do analog stuff account for the sounds made by what you are describing? Its all Geek to me, but looking up the schematic and the CMOS chip at the core brought back fond memories of starting to dabble with chips and simple circuits?
I used to dabble with 4000 series CMOS and although it was intended to work in the digital domain you can indeed get it to function in the analog domain, but we are not talking about hi-fi here! I never thought about starving the power supply though. It's kind of genius.
The C in CMOS stands for complementary as there are two MOSFETS in an invertor that work in opposite directions. The idea being that unlike older TTL logic the power consumption was very low when used as intended as almost all of the time one of the MOSFETS would effectively be open-circuit. But biasing the input to be somewhere between on and off forces the MOSFETS into a narrow linearish range. This kind of short-circuits the power supply so power consumption goes up a lot. But by playing with the power voltage one could play with this effect and get exactly the interesting results seen. It's wonderful to see something so low-tech - you could build one of these things for peanuts.