VM-3100PRO: Locking to Video with ADAT in conjunction with the VM-3100Pro

Tags: vm-3100pro
The VM-3100Pro makes an ideal mixer for a video editing or post-production
suite. The RMDBII interface allows the VM-3100Pro to work in conjunction with
a number of recording platforms common to video post-production. Alesis ADAT
recorders are common to many kinds of video production studios.

A very typical application in the audio post-production environment is locking
to video using the timecode on the videotape as a source. This kind of video
tape is called a Code-Only Master since it carries SMPTE timecode on either a
track dedicated to SMPTE or on one of its audio channels. In this
configuration, the video tape recorder controls the devices connected to it
when it is engaged in playback mode or fast forward or rewind.

To lock the ADAT to the video recorder, a synchronizer interface for the ADAT,
such as the Alesis AI-2 or the Alesis BRC is required. Using the AI-2 as an
example, the connections consist of running a balanced 1/4î TRS cable between
the AI-2ís SMPTE IN connector and the video tape recorderís SMPTE OUT. In some
cases, the SMPTE might be recorded onto either the left or right audio track of
the tape. In this case, connect the cable to the proper channelís output
connector. Next, a BNC connector is attached to the video recorderís VIDEO OUT
to the AI-2ís VIDEO IN. The AI-2ís ADAT SYNC OUT is connected to the ADAT
recorderís SYNC IN.

The ADAT recorder is connected to the VM-3100Pro via the RMDBII interface. The
ADAT SYNC OUT is connected to the RMDBIIís ADAT SYNC IN. The ADAT optical
cable is connected from the ADATís DIGITAL IN to the RMDBIIís ADAT DIGITAL

The VM-3100Pro can be used to mix microphones for narration or voice-over and
music tracks from computers or MIDI sequencers. Computers or MIDI sequencers
can be synced to the ADAT recorder and the video recorder using VM-3100ís MMC
transport controls. This would require a MIDI cable connected from the
VM-3100ís MIDI Out to the MIDI In of the connected devices.