So I just finished a major project for my parents. I made DVD's of all their camcorder tapes, 30 tapes spanning 35 years. Everything was going well until Vegas started outputting garbage AC3 files. I am using Vegas 11 64bit (Build 511). The AC3 render process runs and completes as normal, DVDA will even open it and builds peaks for it. However the audio is junk, it is 2 relatively straight lines and just a humming noise. There is no consistency to the problem, sometimes Vegas will render a good file the first time other times it will take 5 or 6 attempts. I have uninstalled and re-installed Vegas but the problem remains. Any help would be appreciated.

Which AC3 template are you using?

Have you tried exporting as a different format (like .wav) ?

Will DVDA transcode all audio into AC3? Or does it make you start with an AC3 file to be totally compliant?

I have tried all AC3 options, AC3 studio and pro. All have the issue, I use AC3 because DVDA uses it natively without the need to re-encode. I will try other audio formats to see if they have the same problem.

Don't know what might be causing the problem but if you give DVDA a wav (PCM) file it will simply render it to AC3 without detriment to the file. Then before you birn it check it in DVDA to make sure it's OK.

So I tried other audio formats tonight MP3 and Wav, both had no issues. I decided to try AC3 again and was able to do 6 different renders in a row without issues. I have no idea why it is working fine now after 2 weeks of problems. The only thing that has changed on my system is that I installed the 2 MS .net updates from last week. Well thanks for the suggestions, hopefully the problem does not return.