[Mondial]

The problem is that you have installed the wrong value resistors at 43 and 45. Where there should be a 470K resistor, you have installed 470 ohms, and for the 680K you have instead 680 ohms. This explains why the voltage is wrong on pin 7 and why the audio is very low.

Please learn the resistor color code. A 470K resistor should be yellow-violet-yellow-silver and 680K is blue-gray-yellow-silver.

Replacing these resistors with the proper ones should cure the low audio problem.