Synching Cakewalk To SMPTE

The first thing to consider when dealing with SMPTE is that it is like a very specific digital clock. It indicates hours, minutes, seconds and frames (of film). Also when using it in conjunction with a sequencer, there are two "start" times that must be kept in mind. First is the tape's "start" time and secondly the sequencer's "start" time or, Time Offset in Cakewalk Professional.

To stripe a tape with SMPTE:

SMPTE is encoded onto tape via what is called a SMPTE generator/reader. This is a device that not only produces the signal (that's what SMPTE is, an analog signal) but "reads" it in and converts it to the MIDI equivalent known as MIDI Time Code or MTC for short. The process of recording a SMPTE signal onto a tape track is call "striping ".

1. Set the SMPTE generator/reader to its "striping" mode and set the stripe start time (usually 00:00:00:00).
2. Record the SMPTE signal onto a track of the tape recorder. It is usually best to use the last tape track to help keep other signals from bleeding into the stripe track or vice versa.

Note: Try to think of the signal as playing into the recorder just like an instrument's audio signal would. An optimal level to record the SMPTE signal is approximately -3db to 0db. Do not monitor the SMPTE signal, it sounds awful.

To SMPTE sync to tape:

The sequencer has nothing to do with the "striping" process at all but it does get involved when it comes time to play back the song or overdub to it "in sync" with the tape.

1. Put the generator/reader into its conversion mode. It will take the SMPTE signal and make it into something the sequencer can use, MIDI Time Code. This is basically the MIDI version of SMPTE.
2. Play back the SMPTE signal just as you would any instrument track on the tape recorder. Send it directly to the generator/reader by connecting the the Tape Out of the sync track to the generator/reader's MIDI IN or the Sync In of your MIDI interface (see the Note below).
3. Connect the MIDI Output of the generator/reader to the MIDI In of the computer. This will provide the MTC to the computer for use by the software.

Note: There are many "conversion capable" MIDI interfaces that can do SMPTE to MTC conversion right on the card itself. This is convenient for studios that do only MIDI tracks.

Once we start the tape machine playing the SMPTE is sent to the generator/reader which will do the conversion and in turn, send the signal to the computer for use by the sequencing software. Call up a file in Cakewalk and take the necesarry steps to run it in SMPTE sync mode. Cakewalk will take it from there.

Here are the steps to take in Cakewalk:

1. Choose Options | Project | Clock. Select SMPTE/MTC as the clock source.
2. In the Clock menu, choose the correct Time Format of your SMPTE stripe (see the Note below) and setup a Time Offset (the time that tells Cakewalk when to turn on). If the tape start time is 00:00:00:00, the sequencer start time should be set around ten seconds later or 00:00:10:00. This amount of "chase delay" is important.
3. Pull down the Real-time menu, click on Auto Shuttle and put an "x" in the box labeled Restart. This will cause Cakewalk to chase the SMPTE whenever you stop and restart your tape transport.

Note: The actual SMPTE time format is a very involved topic. For most music applications not having to do with film or video, 30 Frame Non-Drop is the popular choice. Simply choose this fromat on your generator when you originally stripe tape and in the Settings/Time Format dialog box when you sync up in Cakewalk.

Now, to play back the file hit the Play button on Cakewalk. A "Waiting for 30 Frame Non Drop" sign will pop up. Start up your tape transport to play the SMPTE out of the tape machine. If you striped your tape starting at 00:00:00:00, the first instance of time code to reach the converter will also be 00:00:00:00. The generator/reader or "conversion capable" MIDI interface will convert the code to MTC send it to the sequencer. When the first instance of MTC reaches Cakewalk, the "Waiting for 30 Frame Non Drop" sign will change to say "Chasing" and scroll the current SMPTE time. When 00:00:10:00 is reached, Cakewalk will turn on and continue to playback the file as long as the tape transport is playing SMPTE.

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