Do you have positive DC going to ground? -9vdc is your VCC (common collector voltage)..
It will work both ways, i.e, with a negative ground, just make sure you observe the correct polarities on, yup, transistors and electrolytics..
Just had a new enclosure tonight with a piece of carbide, I guess from the end of the tap, broke off inside one hole. Luckily, I had enough thread to get the lid screw started, so I tightened it down to crunch up the little s.o.b..
Sorry, only kind of an answer, but I highly recommend checking out the datasheet for the lm386. Specifically section 9.2.1.2. It details how to get around 6 dB of bass boost with a super simple RC link between pins 1 and 5!
What size potentiometer did you use for the gain control? If it's at...
You need a switching 2.1 mm jack to take the battery + out of circuit when you plug in a power supply, otherwise you send voltage to the battery, which will then let out the magic smoke!💥
If the battery is not inserted when the power supply is, and vice-versa, it should be ok..
Is Ohms law not taught anymore? Genuinely asking. It was a major part of my early (basic) electronics knowledge. I highly encourage everyone to learn it. Do some figures, calculate current, voltage drops,etc. Then get an app that does it for you..:cool: