User Manual

AUDIO SYNC
970
Frame-accurate sync to SMPTE time code
If you use SMPTE time code as a master sync
source (such as LTC recorded on an analog multi-
track tape machine), you can use a MOTU MIDI
Timepiece AV™ to convert the SMPTE time code
into word clock and MIDI Time Code. Figure 87-4
below shows how a system like this is can be
configured with a MOTU HD192 analog audio
interface. In this scenario, slave Digital Performer
to SMPTE time code as explained in “MTC (MIDI
Time Code)” on page 955. Slave the audio interface
to its word clock input.
SYNC AND THE COMPUTER’S BUILT-IN
AUDIO
Digital Performer can play audio tracks via the
computer’s built-in audio hardware while Digital
Performer is slaved to external time code. Setup is
done in the usual way as described in “MTC (MIDI
Time Code)” on page 955.
However, because the computer’s built-in audio
hardware has no way of continuously resolving to
an external source, Digital Performer has no way to
continuously resolve audio tracks to external time
code — or the MIDI tracks they are playing along
with. MIDI and audio tracks will always start
exactly at the correct position when external time
code is first received. But after playing for a while,
audio tracks may drift out of sync with MIDI
tracks.
SMPTE Time Code Source
(Multitrack)
MIDI Timepiece AV™
SMPTE time code (LTC)
Figure 87-4: Frame-accurate audio sync to MIDI Time code.
SMPTE
to
MIDI
converter
Word ClockMIDI Time Code
Digital Performer System
SMPTE
to
Word Clock
converter
MOTU HD192 audio interface
(or any word clock-equipped audio interface)
Audio
playback engine
MIDI
playback engine