I had similar issues - from time to time sound just stopped working, so I switched to following kext:i have try delete all injected binary and re-apply alc_fix the result is same not working and still have buzzing sound
I don't remember that I made any special settings. You can check for yourself - config.plist in the attachment.Do you use any configuration in the config.plist to make it work properly with jack? Which os version are you running? Audio Jack doesn't work in my case, and I use AppleALC kext.