In all the years of using Vegas I have never needed to record audio directly to the timeline. Yesterday I finally needed that feature, and I can't seem to locate the "Arm For Record" button on any of the audio buss elements (timeline, master, etc). I'm using 8.0c, but I checked and 8.1 is the same.
I ended up using Cool Edit Pro to record the tracks, so I guess the audio chipset (built-in Realtek chipset) works to map sound / audio correctly. But whether it works with Vegas is another question.
I did notice that under the "Preferences" / "Audio Device" the item labeled "Default audio recording device" is ghosted.
Any ideas?
Jim