[C. Park seward]

It’s all about headroom. As you know, 0 DBfs is as loud as you can be: anything above is distortion. In the analog world, you didn’t have a hard ceiling, just increasing distortion. You wanted to get your level high enough so it didn’t sound noisy but low enough so it didn’t contain too much distortion. Many analog audio recorders set peak levels at 3% distortion which gave them around 60 db noise floor. They set their “0” to a certain magnetic signal strength (like 186 nanowebers per meter) to fit audio between distortion and noise.

Since a Digital Betacam VTR samples 20 bits in audio, your S/N ratio is very high. Subtracting 20 db won’t hurt at all.

While many broadcasters will accept tapes with incorrect reference levels, you should use the proper reference level of the machine you are dubbing to. It is a mark of professionalism to set proper audio and video reference levels. -20 db can be used for all broadcast formats.

[C. Park seward]

There may be some confusion here. They may mean to make sure proper timecode is on the timecode track, which on Betacam is analog track three. On Betacam SP, track three is referring to one of the two FM tracks. No one puts audio there.

Putting timecode on an audio track is redundent. The timecode exists on the timecode track. I have never put Betacam timecode on an audio track for broadcast. Now if I needed to sync to an external source in post and wanted a TC reference along with a different TC on the TC track, I would put TC on an audio track. But not on a release tape.

Park