You Shore is RIGHT ! How ya doin' Alain ?
I just sort of think the author of this code expected users to download and not dissect the code, foolishly I filtered it through Google translator, then spent an hour fixing what Google did to it What I learned was the author is worried about audio pulses above 5 volts blowing the pic's inputs and he suggested resistors and zeners to clip those voltages. I am guessing he might have used it on speaker outputs, whereas our member I think wants it on his preamps.