Akai DD1500

SYSTEM SETUP - 10
Version 2.00 - March, 1996 Page 51
EBU 25fps (+4%) - This special selection should be made
when working with video material that has been derived
from a frame-by-frame transfer from 24 fps film to 25 fps
video. When material is transferred in this way, the visuals
will actually run 4.1% faster when played from the video. As
a result, the DD1500 needs to playback audio with the
same speed offset in order to maintain sync.
This selection should be used when working with material
that has been transferred from film in this way. Whilst
working with the video, the audio will play back slightly
faster and may sound unnatural but this is not a problem
as, ultimately, the audio will be played back synced to the
master film at 24fps at which point, correct playback speed
will be restored.
NOTE 1: It is not possible to record audio when synchronised to this selection.
NOTE 2: You must select 25fps (+4.1%) as the time display style - see below.
SMPTE/EBU+RS422 - These options are available at all
frame rates and are for use with RS422 equipped VTRs
when the DD1500 is acting as an RS422 master controller
(i.e. when all playback, locating, jogging, etc., of both the
DD1500 and VTR are controlled from the DL1500).
SMPTE/EBU from the VTR is still connected as usual via
the EXT. TIME input and the EXT.TIME key must be
switched on (as must the EXT. M/C key). The DD1500 will
receive timecode information in playback from the LTC
connection but, when working in slow motion, it receives
timecode over RS422 making locking of the two machines
tighter.
NOTE: The SMPTE+RS422 selection described above MUST be used from now on when
using the DD1500 as an RS422 master.
SMPTE/EBU+VITC - These options are available at all
frame rates and allow the DD1500 to follow SMPTE/EBU
timecode as normal during playback but, during extremely
slow motion playback or jogging, the DD1500 automatically
switches to VITC for better slow motion lock between the
machines. Naturally, both the LTC and VITC inputs must
be used when this timecode selection is made.
NOTE: When the DD1500 switches to VITC at very, very slow jog speeds, you will not hear
audio as you jog but you will notice improvements in the accuracy of frame locking at such
slow speeds.
RS422 - It is also possible to synchronise the DD1500 to
timecode over RS422 only and all frame rates are
supported. However, you will note that this is primarily of
use when using the DD1500 with a non-linear video
recorder (see the section that explains the RS422 functions
for more details on this).