First off, I’d like to say that pointing me towards definitions of Vcc just proved my point about obfuscation. There are 2 modes of electrical power on this planet, AC & DC. To leave off mention of either one of them on a data sheet seems beyond stupid to me.
Bertus, I added a 100uf cap and a .1uF cap to my soldered board, on both the drones and chanter circuits—which I didn’t have on the breadboard. I had added a nice new, tiny ceramic .1 cap across the “Vcc” and ground pins of each IC, beneath the board, with leads as short as possible. Yesterday, I removed the 100uF cap from the drones circuit, as well as the .1 cap from the drones circuit flip-flop IC (because there was no way to have nice short leads on that one; the pins are at opposite ends of the IC). It didn’t seem to make any difference.
Then, I built a bandpass filter and added it before my amp. I used high-pass and low-pass calculators to figure out capacitor and resistor values for both sides of it and was targeting frequencies as close I could get to to 261 and 932Hz. I put 2 trim pots in the filter, to try to get the resistances spot-on. It did nothing. It didn’t even knock out or knock down my drones. I started playing with the 2 trim pots, and it struck me that they mostly worked like 2 extra volume controls.
With the filter that you‘ve shown above, Bertus, are there any guides for component values, or would I be experimenting with that vast range for 3 of the components, if I decide to try it?
I also spent quite a lot of the day yesterday researching SMPSs and audio problems and every page I hit upon seemed to be aimed at SMPS designers, not at audio circuit designers.
And Alec, your question is interesting and rather psychic. I haven’t tried detuning the drones. However, my new chanter circuit takes output from BOTH the timing cap and from the output pin, runs them through 1N4148 diodes and then to my mixing circuit. Actually, I’m figuring that the 2 diodes form another mixing circuit for the 2 outputs I’m taking from that 555 timer. (Feel free to disabuse me of that notion.) I think the addition of the output from pin 2 makes the chanter circuit a little bit more nasal sounding. (I have the circuit diagrams on my desktop computer. If someone wants to see them, I’d have to boot that up... They are also in the second PDF on my mediafire page: https://www.mediafire.com/folder/q4ave4tjk87ns/Bagpipe_Project