metal detector

This is the schematic and the pcb version which is a bit different but overall the same thing I built the exact same pcb years ago I literally printed this pcb And the circuit worked perfectly It was there in my basement and I forgot to cover the pcb with a layer of epoxy or something to prevent...

Hi All, I am considering ordering some parts for a theoretical circuit, and I am wondering if you think it would work. Basically, it's an induction balance very low frequency metal detector circuit that would use a PAM8403 audio amp IC, a speaker, a battery, and two inductor coils. My theory...