News magazine, interview, and reality productions often require transcription recordings with corresponding time code. With its built-in recorder and time code reader the 552 can easily accommodate this requirement.

There are two ways to record MP3 files with time code using the 552. The first is with Linear Time Code (continuous, audible time code) recorded directly to a track. Recording an MP3 file with LTC  is identical to recording analog audio with cassettes, with LTC time code on the left channel and mono program audio recorded on the right. The second, pioneered by Sound Devices, is recording  time code stamped MP3 files. This second method generates files much like Broadcast Wave files, having a single time code stamp in the file header. Transcription playback software must be able to read and interpret this time code value.

When recording LTC as audio, only a single audio track is available for program audio, one track is program and the other is time code. When recording time code stamped MP3 files, both channels of audio are available.  Also, the MP3 file will play back normally without hearing the recorded time code signal in one channel.

Check with the transcription house to make certain they accept time code stamped MP3 files. If you can not contact them, the LTC method is more foolproof.

To prepare the 552 for transcriptions there are several menu settings to set. Two are common to both types of transcription:

  1. Record Mode (-20): Select 128k MP3 (-20)
  2. Sample Rate (-16): Select 44.1 kHz (-24)

Recording LTC Time Code to a Track

To "stripe" LTC time code to a track, select the menu item “Input 1 Pre-Fade, Left/Right Mono Program” (-12) in the AES A Source menu (-10). This menu sets the program source for the on-board recorder.

The typical method is to use the internal TC routing of the 552. In the Timecode Menu (-14) select “Replace Left” (-22). Connect the timecode signal cable to the Return B TA3. The Time code LED will illuminate to indicate valid time code at a good level. Time code will not be audible when recording or playing back through the mixer.

Another  method or recording LTC time code to a track is by using an input. Directly connect a LTC source to input 5 of the mixer. Set the input to line level, use the preamp trim to set a good time code signal level, and hard pan input 5 opposite all other inputs.

Time Code Stamped MP3 Files

Recording MP3 files with time code stamped in the header is similar to the method above, but leaves both record tracks available for audio.

  1. Select "Left, Right Program" in the AES A Source Menu,
  2. Select "Stamp files" in the Time Code menu.

Make certain that the transcription house can accept time code stamped MP3 files. Note that the use of record pause will generate files with invalid time code.