Part 1: the board and how it's connected
I'm looking at a headphone sound amplifier that is used to help experts detect pests in palm trees when a microphone is placed on the trunk of the palm tree. Here's what the board looks like on the front,
On the left side are 9V battery wires coming in to supply the whole circuit . Top right is ( i presume ) microphone pre-amplifier circuit which has input from a microphone ( silver Wire is the Signal Line while the bare wire is ground ) , the output of the BJT microphone circuit (brown wire) gets through a potentiometer to the input of the unknown IC (red wire) , the IC is then connected to the purple and blue wires which go to the headphone . The yellow and green are 9V Lines that are connected / disconnected through a switch .
Part 2: my conclusions for far
Here's my guess,
- The BJT circuit is a microphone preamplifier circuit .
- The IC is some sort of a special purpose Audio-ish amplifier .
Part 3: schematic of the board
Part 4: my questions
What is the IC Model/Type/Category .
BJT Circuit drawn earlier ( Preamplfier ? ) .