Sound Devices 664 - Manual (Page 40)

The audio file, however, is stamped with a 29.97 ND frame rate, along the 48 kHz sampling rate. It
will appear as if the file was originally recorded at a 48 kHz sampling rate at a TC rate of 29.97 ND.
Fostex DV40
When using files recorded in the 48.048kF mode with a DV40 with early software, set the DV40 time
code frame rate to 29.97ND. Time code stamps will properly match the original time code start times.
47.952k and 47.952kF
Both 47.952 and 47.952kF settings use a record sampling rate of 47.952 kHz, 0.1% lower than 48 kHz.
The 47.952kF mode, however, identifies the file as being recorded at 48 kHz. Additionally there are
two frame rate options in 47.952kF mode. The time code frame rate can be set to 23.97 while the file
is identified as 24ND or it can be set to 29.97ND while the file is identified as 30ND. By default, when
47.952kF mode is selected the frame rate is changed to 29.97ND and identified as 30ND unless the
Frame Rate was already set to 23.97 in which case it will remain at 23.97.
Pre-Roll
To prevent missing record cues or up-cutting takes, the 664 has pre-roll buffering available. When
active, pre-roll begins recording at a set number of seconds preceding the record button being
pressed. The Pre-Roll time can be adjusted from the Setup Menu option RECORDER > Pre-Roll Time.
Maximum pre-roll time is 3 seconds when recording mono WAV files to any media. In all other cases,
maximum pre-roll time is 6 seconds.
Pre-Roll is disabled when the time code mode is set to Record Run,
External Time Code Auto Record, or External Time Code Continuous Auto Record. This prevents
possible overlapping time code numbers between adjacent files.
Synchronization
A stable sample clock source is essential for high quality digital audio. Setups involving multiple
digital recording/playback devices often require that all devices are locked to a common clock refer-
ence to ensure they are synchronous, i.e. run at the same speed and in phase with one another. The
664 uses rock-stable word clock and PLL circuitry to generate its internal clock frequency.
The 664 can act as either a clock master (Setup Menu option TIMECODE/SYNC > Sync Reference
set to Internal), where it is the provider of word clock, or as clock slave (Setup Menu option
TIMECODE/SYNC > Sync Reference set to Word Clock), where it locks its internal word clock to a
received external master reference clock. External word clock signal is provided via the Word Clock
input BNC on the Rear Panel.
When accepting digital input signal, the 664 always converts the sample rate to the recorder’s
sample rate. During playback, the 664 only uses its own word clock, ignoring external word clock.
File Management
The 664 writes files to both CompactFlash (CF) and Secure Digital (SD) storage media. Stor-
age media must be formatted prior to use with the 664. CF and SD storage media inserted
into the 664 can be formatted with Setup Menu option FILE STORAGE > Erase/Format CF and
FILE STORAGE > Erase/Format SD respectively. The 664 formats CF cards of any capacity and SD
cards of 16 GB or less with the FAT32 file system. SD cards with a capacity greater than 32 GB are for-
matted with the exFAT file system. To manage files on 664 media using a computer, simply remove
the media from the 664 and insert into a compliant CF or SD card reader connected to a computer.
664 User Guide and Technical Information
v. 2.02 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.
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