i'm sorry but in my usb installer i don't have the vanilla AppleHDA. i've only the AppleHDA_ALC292.kext that i've already replaced in /S/L/E, without any results. then, i tried the vanilla AppleHDA that I've downloaded from the link I posted earlier, always with no result. if you want I also have the terminal output of the latter test... now, i think my problem is the DSDT like i wrote yesterday. i said this because now i've 2 DSDT on my dell. in the first, the "original" DSDT, everything works except for the wifi and sound, and in the second everything works except for the wifi and card reader. so, with the second DSDT laptop sound work good! with the same kext. but I would try to use the original DSDT because I feel that it is more stable and performing overall...
i tried to find difference between them and patch them lot of time but probably i'm not able to do that and, after that, i've always kernel panic.
so, I repeat myself, I think that is not a kext problem but it is a problem of another nature.
anyway, thank you very much for all the help that you're giving me