The electronics engineer who helped design my custom PCB used the schematic below:
However, on the store-bought (PAM8610) amplifier, I noticed a large capacitor that my custom PCB does not have. I am trying to identify any components that I could add/remove to give the same performance as the PAM8610 store version. Could it also have to do with the quality of the components? I got the pcb made by pcbway.