For some context, see my earlier question: Ceramic capacitor value for an LM386N project
What I learned is that the 10k potentiometer on pin 3 (Vin) forms a voltage divider. When I carefully dial it, I find a spot where I get clean audio (the 10k pot is then at ~ 500 Ω). This is the same with the ready-made breakout board that I used for comparison.
Now the point of not using the ready made module was that I wanted to add a volume control. Apparently scaling Vin is not how one supposed to do that. If I go up or down from the spot where the audio is good, I get distortions, but never a quieter signal.
I also tried to add a pot between pin 1 and the ceramic capacitor that goes to pin 8. The datasheet has three examples:
- gain 20: by default there is a 1.35 kΩ resistor
- gain 50: use a 1.2 kΩ resistor
- gain 200: use no resistor
I only had a 2k potentiometer and when I dial it from 0 Ω up, the signal gets a bit quieter, but I can't get it down to silence. If I remove the circuit between pin 1 and 8 to operate at gain 20, the output is pretty quiet though.
I searched the Internet quite a bit, and I probably miss something obvious. It would be awesome to get some pointers.