Sound Devices 744T User Manual

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744T

High Resolution Digital Audio Recorder with Time Code User Guide and Technical Information

firmware rev. 2.67

SATA

2.5" HDD

Sound Devices, LLC

E7556 State Rd. 23/33 • Reedsburg, WI • USA +1 (608) 524-0625 • fax: +1 (608) 524-0655 Toll-Free: (800) 505-0625 www.sounddevices.com support@sounddevices.com

backside - front cover

Table of Contents

Quick Start Guide .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	1
Powering the Unit
Menu Navigation Basics
Connecting Audio Sources
Routing Inputs to Tracks
Selecting Recording Parameters and File Destination
Time Code Setup
Recording
Playback
FireWire File Transfer to Computer
Front Panel Descriptions .. . . . . . . . . . . . . . . . . . . . . . . . . . . .	4
Panel Lock
LCD Display Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 7
Left Panel Connectors and Controls . . . . . . . . . . . . . . . . . .	. 9
Right Panel Connectors and Controls . . . . . . . . . . . . . . . . .	10
Back Panel Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . .	11
Input Setup and Control . . . . . . . . . . . . . . . . . . . . . . . . . . . .	12
Input Source Selection
Analog Inputs 1 and 2
Input Linking (Stereo or MS Decoding)
Analog Inputs 3 & 4
Digital Inputs – AES3
Digital Inputs – AES3id (S/PDIF)
Signal Presence and Peak Indicator
Input Delay
Input-to-Track Routing .. . . . . . . . . . . . . . . . . . . . . . . . . . . . .	16

Selective Input Muting

Sampling Rate and Bit Depth . . . . . . . . . . . . . . . . . . . . . . . . 17

Sampling Rate

Bit Depths

Word Clock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Clock Master

Clock Slave

Multi-Unit Linking Via C. Link

Outputs – Analog and Digital . . . . . . . . . . . . . . . . . . . . . . . . 20

Master Output Bus
Output Bus 2
Headphone Output .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	22
Selecting Headphone Sources
Setting Headphone Source Options
MS Stereo Monitoring
SoundField B-Format Surround Monitoring
Rotary Switch Behavior
Headphone Favorite Selection
Headphone Playback Mode
Headphone Warning Tones
Metering and Display .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	26
Output Meter
Meter Ballistics
Peak LEDs
Tone Oscillator
LCD Contrast & Backlight, LED Brightness
LCD Gain Display
Record Indication
Time Code .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	29

Frame Rate

F Sampling Rate Modes

Time Code Modes

Time Code Hold Off

Jam Menu

User Bits

NTSC Standard Def Video Production

Recording . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

Recording

Pre-Record Buffer

Failure During Recording

Record Pause

Record Timer

Playback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

AutoPlay
Audio File Formats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	37
.WAV

.FLAC

.MP2

.MP3 iXML

Recording Time Calculation .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. 39

Uncompressed Recording Time in Track-Hours
MP3 Compressed Record Time in Hours
File Naming / Numbering .. . . . . . . . . . . . . . . . . . . . . . . . . . .	41
Scene Name/Numbering
Mono Track Name Designators
Duplicate File Names
Wave Agent Beta.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	43
File Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	44

Folder Actions

File Viewer Navigation

File Viewer Screen

File Time and Date

File Size Maximum

Setting/Clearing Flag Bits

Automatic Flag Clearing

File Copying Among Available Drives

File Deletion

False Take Control

Emptying the Trash and False Take Folders

Take Number Incrementing

Take List

Take Status

Storage Medium – Internal Hard Drive .. . . . . . . . . . . . . . . . 50

Formatting
Drive Type
Drive Replacement
Drive Failure
Storage Medium – Removable CompactFlash . . . . . . . . . .	53
When to Use CF
Formatting
Speed Testing
Qualified CF Cards
Storage Medium – External FireWire Drives. . . . . . . . . . . .	54
When to Use External FireWire Drives
Formatting
FireWire Bus Powering
Qualified Drives
DVD-RAM Drives
File Transfer Using FireWire . . . . . . . . . . . . . . . . . . . . . . . . .	56
Powering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	57

Lithium Ion Rechargeable Battery External Powering and Battery Charging Time Code Clock Battery

Auto Functions with External Powering Power-up Messages

Power Consumption Variables

Firmware Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Version Information
Upgrading Firmware
CL-1 Remote Control and Keyboard Interface . . . . . . . . . .	61
Connecting the CL-1
Logic Inputs
Logic Outputs
Setup Menu Presets .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	64
Built-In Presets
User Setup Data File
Setup Menu .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	67
Setup Menu Shortcuts
Front Panel Button Shortcuts . . . . . . . . . . . . . . . . . . . . . . . .	75
Connector Pin Assignments .. . . . . . . . . . . . . . . . . . . . . . . .	76
Specifications .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	77
Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	79
CE Declaration of Conformity . . . . . . . . . . . . . . . . . . . . . . . .	81
Software License . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	82
Warranty and Technical Support . . . . . . . . . . . . . . . . . . . . .	83

744T User Guide and Technical Information

Welcome

Thank you for purchasing the 744T. The ultra-compact 744T records and plays back audio to and from its internal hard drive, CompactFlash, or external drives, making field recording simple and fast. It writes and reads uncompressed PCM audio at 16 or 24 bits with sampling rates between 32 kHz and 192 kHz. It also writes and reads data compressed FLAC and audio compressed MP2 and MP3 files. The time code implementation makes the 744T ready for any recording job—from over- the-shoulder to cart-based production.

The 744T implements a no-compromise audio path that includes Sound Devices’ next generation microphone preamplifiers. Designed specifically for high bandwidth, high bit rate digital recording, these preamps set a new standard for frequency response linearity, low distortion performance, and low noise.

With documentary and ENG mixing engineers in mind, the 744T is very small, while still being feature-rich. No other recorder on the market matches its size and feature set. In addition, its learning curve is quite short—powerful does not mean complicated. While the 744T is a very capable recorder by itself, it truly excels when used in conjunction with an outboard audio mixer such as Sound Devices’ own 442 or 302.

Sound Devices took advantage of the best in professional and consumer electronics technologies to bring incredible feature depth with ease of use. Hard drive and CompactFlash are highly reliable, industry standard, and easily obtainable. With the ability to write to an external drive, a low-cost, portable medium can be turned in to post production. The removable, rechargeable battery is a standard Sony-compatible Li-ion camcorder cell. The 744T interconnects with Windows and Mac OS computers for convenient data transfer and backup.

744T Firmware Known Issues

For a complete list of known issues regarding the most current firmware please visit Sound Notes. http://www.sounddevices.com/notes/recorders/known-issues/

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the expressed written permission of SOUND DEVICES, LLC. SOUND DEVICES is not responsible for any use of this information.

Microsoft Windows is registered trademarks of Microsoft Corporation. Macintosh is a registered trademark of Apple Computer. Other product and company names mentioned herein may be the trademarks of their respective owners.

The sound waves logo is a registered trademark of Sound Devices, LLC.

Limitation of Liability

LIMITATION ON SOUND DEVICES’ LIABILITY. SOUND DEVICES, LLC SHALL NOT BE LIABLE TO THE PURCHASER OF THIS PRODUCT OR THIRD PARTIES FOR DAMAGES, LOSSES, COSTS, OR EXPENSES INCURRED BY PURCHASER OR THIRD PARTIES AS A RESULT OF: ACCIDENT, MISUSE, OR ABUSE OF THIS PRODUCT OR UNAUTHORIZED MODIFICATIONS, REPAIRS, OR ALTERATIONS TO THIS PRODUCT, OR FAILURE TO STRICTLY COMPLY WITH SOUND DEVICES, LLC’S OPERATING AND INSTALLATION INSTRUCTIONS. TO THE FULLEST EXTENT PERMITTED BY LAW, SOUND DEVICES SHALL HAVE NO LIABILITY TO THE END USER OR ANY OTHER PERSON FOR COSTS, EXPENSES, DIRECT DAMAGES, INCIDENTAL DAMAGES, PUNITIVE DAMAGES, SPECIAL DAMAGES, CONSEQUENTIAL DAMAGES OR OTHER DAMAGES OF ANY KIND OR NATURE WHATSOEVER ARISING OUT OF OR RELATING TO THE PRODUCTS, THESE TERMS AND CONDITIONS OR THE PARTIES’ RELATIONSHIP, INCLUDING, WITHOUT LIMITATION, DAMAGES RESULTING FROM OR RELATED TO THE DELETION OR OTHER LOSS OF AUDIO OR VIDEO RECORDINGS OR DATA, REDUCED OR DIMINISHED AUDIO OR VIDEO QUALITY OR OTHER SIMILAR AUDIO OR VIDEO DEFECTS ARISING FROM, RELATED TO OR OTHERWISE ATTRIBUTABLE TO THE PRODUCTS OR THE END USER’S USE OR OPERATION THEREOF, REGARDLESS OF WHETHER SUCH DAMAGES ARE CLAIMED UNDER CONTRACT, TORT OR ANY OTHER THEORY. “CONSEQUENTIAL DAMAGES” FOR WHICH SOUND DEVICES SHALL NOT BE LIABLE SHALL INCLUDE, WITHOUT LIMITATION, LOST PROFITS, PENALTIES, DELAY DAMAGES, LIQUIDATED DAMAGES AND OTHER DAMAGES AND LIABILITIES WHICH END USER SHALL BE OBLIGATED TO PAY OR WHICH END USER OR ANY OTHER PARTY MAY INCUR RELATED TO OR ARISING OUT OF ITS CONTRACTS WITH ITS CUSTOMERS OR OTHER THIRD PARTIES. NOTWITHSTANDING AND WITHOUT LIMITING THE FOREGOING, IN NO EVENT SHALL SOUND DEVICES BE LIABLE FOR ANY AMOUNT OF DAMAGES IN EXCESS OF AMOUNTS PAID BY THE END USER FOR THE PRODUCTS AS TO WHICH ANY LIABILITY HAS BEEN DETERMINED TO EXIST. SOUND DEVICES AND END USER EXPRESSLY AGREE THAT THE PRICE FOR THE PRODUCTS WAS DETERMINED IN CONSIDERATION OF THE LIMITATION ON LIABILITY AND DAMAGES SET FORTH HEREIN AND SUCH LIMITATION HAS BEEN SPECIFICALLY BARGAINED FOR AND CONSTITUTES AN AGREED ALLOCATION OF RISK WHICH SHALL SURVIVE THE DETERMINATION OF ANY COURT OF COMPETENT JURISDICTION THAT ANY REMEDY HEREIN FAILS OF ITS ESSENTIAL PURPOSE.

vii

Quick Start Guide

The 744T is an extremely powerful and flexible portable audio recorder. Before recording, please familiarize yourself with the product. Several settings should be verified or set based on individual recording needs.

Powering the Unit

1.Apply power to the unit by attaching the (included) removable, rechargeable Li-ion (lithium ion) battery to the back panel battery mount. The metal tabs on the mount line up with the electrical contacts on the battery. From the factory, the battery may not have a charge, so external DC may be needed for initial operation and charging. Connect the included AC-to-DC power adapter to the DC input plug to power and charge the battery.

2.Press and hold the power key to turn on the unit. Press and hold the power key to turn off the unit.

If this is the first time the recorder has been powered, or if it has been without a battery for an extended period, the date and time may need to be set.

Charge the included Li-ion battery for 6 hours prior to initial use.

Menu Navigation Basics

The setup menu provides options for recording, routing, and control parameters. The single layer menu structure allows for very quick navigation and selection of functions. To enter the setup menu press the front panel key. Once in the setup menu, the following conventions are shared for navigating among selections and to select specific parameters.

• - enters setup menu

•ITEM - highlighted menu item

•4 - selects highlighted item or parameter

• - moves up in menu and between menu parameters

• - moves down in menu and between menu parameters

•8 - exits the selected menu or menu altogether

•The stop key will exit from any menu and cancel any changes. Use it to escape out of the setup menus.

The right panel Rotary Switch (labeled “Select”) is a convenient control to quickly navigate among menu items and item options. Its push-to-select function duplicates the check mark in most menus.

Connecting Audio Sources

1.Connect audio sources, either analog or digital, to the appropriate input connector.

2.When using either input XLR, set the appropriate input level—mic, line, or digital—with the adjacent slide switch.

3.If mic-level inputs are used on XLR input 1 or XLR input 2, make certain that phantom power, input limiters, and high-pass filters are activated as required.

4.When using inputs 3 or 4, set gain levels in the setup menu.

744T User Guide and Technical Information

Routing Inputs to Tracks

Before recording, inputs must be assigned to tracks. Each of the 744T’s four inputs (1, 2, 3, 4) can be assigned to any of the four tracks (A, B, C, D). These 256 possible routing combinations are shown on the front panel with 16 blue LEDs. Illuminated LEDs indicate input-to-track assignment.

1.Press and hold the STOP key then press the INPUT key to cycle through factory routing presets. The 744T has six often-used presets for quick setup of input-to-track routing combinations. Note the routing combinations on the blue LEDs with each successive press.

2.If none of the preset routing combinations are suitable, assign a custom routing. Sequential presses of the input key will eventually cycle to the custom routing option (see Input to Track Routing, pg. 18). From the custom input routing menu any input can be assigned to any track, including multiple inputs assigned to a single track.

3.Press EXIT to leave input routing mode.

If no input is assigned to a track the 744T will not record.

Selecting Recording Parameters and File Destination

For most productions, the general recording parameters of bit depth, sampling rate, media selection, and file format are infrequently changed. Enter the setup menu to verify recording settings. Bit depth and sampling rate are displayed on the LCD panel.

1.Select the bit depth as needed.

2.Set the sampling rate as needed.

3.Select the file type, WAV mono or WAV poly, FLAC, MP2, or MP3.

4.Select the storage medium(s) (Internal hard drive, CompactFlash, External drive, or any combinations of the three drives) for recording.

Time Code Setup

When using a time code workflow, proper time code setup is essential for accuracy. Skip this section if time code is not being used.

1.Select a time code frame rate appropriate for your project. For film production, typical the time code rates are 30 fps non-drop (US) or 25 fps (EU). For standard definition video projects, use either 29.97 or 29.97 non-drop. For high-definition projects, use either 23.976 or 29.97.

2.Select the time code run mode: free run, record run, 24 hr. run, or one of the external run modes.

3.Use the 744T as the master clock source and jam time code to all other recording devices. This will

assure that every device is using the same time reference. (See Time Code for additional information on time code setup).

Recording

With file parameters set, you are ready to begin recording. The 744T is a record-priority device— pressing the record key cancels all functions, except file-based operations, and immediately begins recording a new file. When record is pressed, the red record LED illuminates to confirm record mode. The filename on the LCD display shows the currently recorded file. Push and hold the STOP key to end recording.

Playback

When recording is stopped, the most recently recorded file is immediately available for playback. Press the key to begin file playback from the beginning of the file.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

To select a file for playback:

1.Press and hold the File Viewer key to select a drive and folder (directory) for playback. The last file recorded is the default file ready for playback. The default playback source is the storage volume highlighted on the LCD display.

2.Use the Rotary Switch, or the arrow soft-keys, to navigate through the File Viewer.

3. Once a file is highlighted, press the play key to begin playback.

When playback has finished, the filename will begin flashing. Use the fast-forward key or rewind key to step through files in the folder, or press the stop key to exit playback mode.

FireWire File Transfer to Computer

Sound Devices strongly recommends shutting down equipment before connecting to or from any FireWire device with a connection that carries power (6-pin). Reports have come to our attention of isolated problems when hot-plugging IEEE 1394 (FireWire) devices. (Hot-plugging refers to making connections when one or more of the devices—including the computer—is on.) When hot-plugging, there are rare occurrences where either the FireWire device or the FireWire port on the host computer is rendered permanently inoperable. From our experience, any FireWire connection which carries power is susceptible to this type of damage.

When connected via FireWire (IEEE-1394a) to a Mac OS or Windows OS computer (see Specifications for computer requirements), the internal hard drive and CF card mount onto a computer as “letter” accessible mass storage volume. Use the appropriate FireWire cable (6-pin to 4-pin or 6-pin to 6-pin) for interconnection. Files on the 744T can be treated as if they are local files, including renaming files, copying, deleting and playing directly from the 744T hard drive.

In general, it is good practice to copy audio files from the 744T to a computer before any processing is performed on the files.

To connect the 744T for FireWire computer transfer:

1.Stop all playback and recording activity.

2.Make certain the 744T battery is fully charged, or connect to external DC.

3.Connect the 744T to the host computer with a FireWire cable.

4.Initiate connection to the computer by accessing the FIREWIRE: CONNECTION menu option in the Setup Menu. Select COMPUTER/CONNECT or if this has already been selected simply hit STOP then the

HDD key to initiate a connection to the computer. The 744T will enter FireWire transfer, indicated by FIREWIRE CONNECTION on the LCD display. All functions of the 744T are stopped while the 744T is connected to a computer through FireWire.

5.Navigate to either the CF card or hard drive from the computer and copy all needed audio files to local storage on the computer.

To avoid any possible directory corruption on the 744T do not interrupt the connection process and always properly dismount the drives from the operating system. On Mac OS platforms, drag the drive icons to the trash. On Windows platforms, use the “Disconnect External Media” icon in the system tray.

Dismount the 744T after file transfer by “ejecting” the volume from the computer. In Mac OS, drag the disk icon from the desktop to the trash or hit -e. In Windows OS, highlight the disk icon, rightclick, and select “eject”. It is best practice to “eject” the 744T volume from the computer to maintain file integrity (see FireWire File Transfer).

744T User Guide and Technical Information

Front Panel Descriptions

All 744T settings can be accessed and monitored through the front panel LCD and navigation keys. This allows the unit to be placed in a production bag along with field mixers and wireless transmitters and receivers.

1	2		3	4			5		6	7	8	9	10	11
29														12
29												744T
												744T
28
27
26
25
24	23	22	21	20	19	18	17	16	15		14		13

1) Digital Input LEDs

Indicates the presence of digital signal on the respective input. When flashing, indicates that digital input is selected but no valid digital clock signal is present.

2) Input 1 Gain

Controls the analog gain (input trim) of the channel 1 input. Normal mic input range is from 25 dB to 70 dB, low gain mic range is from 10 dB to 55 dB, line input range is from −6 dB to 18 dB. For line-level inputs, this control can be defeated and gain can be setup menucontrolled. If the LCD display shows “locked” when the pot is turned, gain control of the line-level input is menucontrolled. When inputs are linked as a stereo pair, Input 1 Gain controls the gain of both inputs.

3) Input 2 Gain

Controls input 2 gain, as in #2 above. When inputs are linked as a stereo pair, Input 2 Gain controls left-to-right balance.

4) MENU Key

Used to access all 744T setup menu selections. When in menu mode, used to move up through the menu selections. Pressing the HDD and MENU keys simultaneously brings up the time code jam menu.

5) LCD Display

Primary display of 744T status. The LCD is backlit using the LCD backlight control (#15).

6) Tone Oscillator

Press to activate the tone oscillator, press and hold for two seconds or longer to latch on, press again to deactivate. Frequency, tone level, and routing are controlled in the Setup Menu. When in the Setup Menu use the TONE key to enter Setup Menu options and select parameters when the check mark appears in the upper right hand corner of the LCD.

7) Input-to-Track Matrix LEDs

Blue LEDs indicate inputs (1, 2, 3, 4) enabled for recording to tracks (A, B, C, D). A solid blue LED indicates an input is routed to a track. A flashing LED during “custom” routing mode shows the selected input/track combination.

8) INPUT Select Key

Pressing the INPUT key brings up the input muting and routing menu. Hold down the INPUT key and press one of the four indicated soft keys to mute inputs. Pressing the STOP key and the INPUT select key cycles through the

six factory preset input-to-track routing combinations plus the custom routing menu. In the custom routing menu any input can be routed to any track. (See

Input-to-Track Routing)

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

9) Level Meter LEDs

Four, 19-segment track level-meters indicate level in dBFS. Metering ballistics are selected in the setup menu.

10) Power Key

Press and hold to power up the 744T. Press and hold to power down.

11) Charge LED

Indicates the charge status of the onboard battery charger. LED flashes when external power is connected and the removable battery is charging; illuminates solid when battery is fully charged.

12) Power LED

Indicates the 744T is powered and available for operation. LED flashes when the removable battery or external DC is in a low-voltage state.

13) Record Key

Press to record. The 744T is a recordpriority device; pressing this key starts recording and discontinues all other functions, except file operations. Pressing key during recording can set a cue marker or start a new file, as selected in the setup menu.

14) Stop/Pause Key

Press and hold this key for 150 ms to stop recording. In Record Pause mode the STOP key will pause the recording, pressing it twice will finalize the recording. In playback mode, a single press pauses playback (play-pause), allowing audio scrubbing with the FF and REW keys. Another press of the key enters play-stop mode where the FF and REW keys select files for playback from the current directory. One more press of the key exits playback mode. In the setup menu the stop key is also used to exit from any menu, returning to the main display.

15) LCD Backlight Key

Press to toggle LCD and keyboard backlighting. Hold the key and turn the Rotary Switch to adjust the brightness of LEDs. In menu mode, functions as the cancel key.

16) Fast-Forward Key

Performs fast-forward (FF) scrubbing through the played file when pressed in playback and play-pause mode. Playpause indicated by flashing A-time on LCD. Fast forward rate increases the longer the key is held. In play-stop mode (indicated by flashing filename on LCD) selects the next file in the record folder (either daily folder or main folder).

17) Play Key

Plays back the file displayed in the LCD. If pressed immediately after recording is stopped, the most recently recorded file is played back.

18) Rewind Key

Performs reverse (REW) scrubbing through the played file when pressed in playback and play-pause mode. Playpause indicated by flashing A-time on LCD. Reverse playback rate increases the longer the key is held. In play-stop mode (indicated by flashing filename on LCD) selects the previous file in the record folder (either daily folder or main folder).

19) HDD (File Viewer) Key

Press to enter the File Viewer. The selected medium shown in white type will be the destination when the button is pressed. Press-and-hold to toggle between available media. If only one media is present, press-and-hold is disabled. Pressing simultaneously with MENU opens the time code jam menu.

20) Headphone Output Peak LED

Indicates overload of the headphone amplifier. When lit, the headphone circuit is overloading. Reduce headphone level.

21) LIM LED

Indicates that the microphone input limiters are engaged. This LED does not show input limiting activity (see descriptor #27, Microphone Input Limiter LEDs).

744T User Guide and Technical Information

22) Link LED

Indicates that channels 1 and 2 are linked as a stereo pair. In link mode input 1 potentiometer controls gain, input 2 potentiometer controls left-to-right balance. Inputs can be linked as either a stereo L/R pair or as a a Mid-Side (MS) pair.

23) Media Ready LEDs

Indicates storage media is present and available to record; IN (internal hard drive), CF (CompactFlash), EX (external FireWire device). Flashing indicates media problem.

24) Media Activity LEDs

Indicates storage media read/write activity. IN (internal hard drive), CF (CompactFlash), EX (external FireWire device).

25) High-Pass Filter LEDs

Indicates that the high-pass (low-cut) filter is active for the input. High-pass only operates when the input is set to microphone level.

26) Phantom Power LEDs

Indicates that phantom power (48 volts) is active for the individual input. Phantom can be applied to microphone or line-level signals (menu-selected).

27) Microphone Input Limiter LEDs

Illuminates orange when limiting is occurring on the microphone input. If constantly lit, the microphone input is being hit with too “hot” of a signal. Reduce the input sensitivity until limiting occurs infrequently.

28) Input Signal Presence LEDs

Indicates presence of analog or digital signal and its relative level on each of the four inputs.

29) Input Peak (Overload) LED

Indicates analog signal is approaching clipping (–3 dBFS) on each of the four inputs. Also used to indicate that an input is muted.

Panel Lock

Press and hold the backlight key then the tone key to bring up the front panel Button Lock Screen. Button lock prevents unintentional changing of settings or record status.The 744T displays any button lock options enabled.

select the soft buttons to activate the appropriate button lock mode

There are three modes:

•Unlocked – all buttons are accessible and operate normally.

•Non-Transport Lock – All front panel controls are locked except the Record, Stop, Play, Rewind and Fast Forward.

•Lock All – All front panel keys are locked except the Record key. The Record key is kept active so the user can initiate recording after entering this mode and enter cue markers. To stop recording in this mode, you must disengage the panel lock and hit the stop key.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

LCD Display Descriptions

1) Battery Level Indicator

Shows voltage level of the removable battery or external power sources. External power overrides battery power when present. Graphical bar for relative level and numeric indicator for precise voltage measurement.

2) File Name Display

Shows file name actively being recorded or played back. In playback-stop mode, flashing file name indicates that the fastforward and rewind keys can be used to step through files in the current playback directory.

3) Absolute Time (A-time) Display

Shows the elapsed time of the file being recorded or played back in hours, minutes, seconds, and tenths. The A- time and the time code display can be exchanged if a large time code display is needed. This display can be set to reverse or flash during recording. Flashes in playback-pause mode.

4) Time & Date Display

Alternating display between the set date and time of the 744T. This information is written as the creation and modification date for generated audio files.

5) Bit Depth Indicator

Shows the set record bit depth. In playback, shows the file bit depth.

6) Sample Rate Indicator

Shows the set record sampling rate. In playback shows the file sampling rate.

7) Time Code Rate

Shows the set time code frame rate. If a file has time code information embedded, the playback frame rate is indicated. If external time code is connected and the external rate differs from the rate set internally, the time code rate will flash.

8) Headphone Source Display

Indicates the source for headphone output. Sources and selection order are user selectable in the setup menus.

9) Time Code Display

In stop and record, shows the time code generated or received by the 744T. In play mode, the display shows the play file’s time code information (if available). If non-time code files are playing, the display shows dashes. The time code display can be exchanged with the A- time display via a user menu selection.

10) External Media Space Status (space remaining/record ready)

If a drive is not attached the indicator shows dashed lines. Bar graph indicates amount of record time remaining on the external FireWire volume. Numbers show time in hours and minutes based on the presently selected number of record tracks, sample frequency, bit rate, and file type.

744T User Guide and Technical Information


13	note the white-on-black number option	15
13	to indicate recording (menu-selectable)	15

11) Internal Hard Drive Status (space remaining/record ready)

Bar graph indicates amount of record time remaining on the internal hard drive. Numbers show time in hours and minutes based on the presently selected of number of record tracks, sample frequency, bit rate, and file type.

12) CompactFlash Status

(space remaining/record ready)

Bar graph indicates amount of record time remaining on the CompactFlash media. Numbers show time in hours and minutes based on the presently selected number of record tracks, sample frequency, bit rate, and file type.

For all three media types, an asterisk in front of the media descriptor indicates that the media is selected for record. Highlighted media descriptor indicates media selected for record monitoring, playback or file directory display.

13) Input 1/2 Level

When input 1 or 2 gain is turned this indicates the gain level in dB for inputs 1 and 2. Gain levels can be selected to

always be displayed in the Setup Menu option LCD: GAIN DISPLAY. Normal

mic input gain range is from 26 dB to 70 dB, low gain mic range is from 10 dB to 50 dB, line input range is from −6 dB to 18 dB. “Locked” will be displayed on the LCD when the pot is turned with digital inputs selected or with line inputs set to menu control.

14) Cue Marker Display

In record mode, indicates when cue markers are set. Markers set by pressing the record key (option must be selected in setup menu). In playback mode, displays cue points numerically as they are reached in a file.

15) External Digital Clock Indicator

The 744T is locked to a valid external digital or word clock source for recording when the L is in the display.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Left Panel Connectors and Controls

3	4	5	6

1	2	8	7
1) XLR Input 1/AES3 Input 1&2		5) TA3 Master (L/R) Analog Outputs

Dual function input connection. Input type set with switch above. Active-bal- anced analog microphoneor line-level input for input 1. Transformer-balanced two-channel AES3 input (1 and 2).

Active-balanced, line-level analog L/R outputs for the Master Output Bus. Program source and attenuation level are user selectable. Pin-1 ground, pin-2 (+), pin-3 (–).

2) XLR Input 2/AES3 Input 3&4

Dual function input connection. Input type set with switch above. Active-bal- anced analog microphoneor line-level input for input 2. Transformer-balanced two-channel AES3 input (3 and 4).

3) Mic-Line-AES3 Input Switch

Selects the input level and mode of the associated XLR input connector.

4) TA3 Channel 3&4 Line Inputs

Active-balanced line-level input connectors. Pin-1 ground, pin-2 (+), pin-3 (−).

6)Headphone Output

3.5 mm TRS stereo headphone connector. Can drive headphones from 8 to 1000 ohm impedances to very high levels. Tip-left, ring-right, sleeve-ground.

7)Headphone Volume

Adjusts the headphone volume. NOTE: the 744T is capable of producing eardamaging levels in headphones.

8) Tape Output

Unbalanced tape (–10 dBV nominal) output on 3.5 mm TRS stereo connector. Signal source is identical to the Master Output Bus. Tip-left, ring-right, sleeveground.

744T User Guide and Technical Information

Right Panel Connectors and Controls

1	2	3	4

1) Time Code Multi-Pin

Time code input and output on 5-pin LEMO® connector.

2) AES3id Inputs 1/2 and 3/4

Unbalanced digital input accepts two channel AES3 (or S/PDIF) on BNC connectors. Supports sample rates up to 200 kHz.

3) FireWire (IEEE-1394) Port

Connection to a computer (Mac OS, Windows 2k/XP, Vista, Linux) to access the internal hard drive and CompactFlash volumes as mass storage devices. Also used to attach external FAT32-for- matted FireWire drives to the 744T for direct recording and copying.

4) C. Link In/Out

RS-232 protocol interface on 6-pin modular (“RJ-12”) connector for linking multiple 7-Series recorders together. Word clock, machine transport, and time code are carried on the C. Link connector.

6) Word Clock Input and Out

Provides clock input and output for the 744T. Word input accepts sampling rates between 32 kHz and 192 kHz. Word clock output is the rate that box is running. There is no sample rate conversion onboard the 744T.

7) AES3id Output Bus 2

Unbalanced digital output, two-channel, for Output Bus 2. Signal source is menuselected.

8) AES3id Master Output Bus

Unbalanced digital output, two-channel, for the Master Output Bus. Signal source is menu-selected and is identical to the Analog Master Output Bus signal.

9) Multi-Function Rotary Switch

When in the setup menu, the rotary switch moves between menu selections; push to enter selection or enter data.

In record and playback modes, selects headphone monitor source; push action is user selectable.

5) External DC In

Accepts sources of 10–18 volts DC for unit powering and removable Li-ion battery charging. The Hirose 4-pin connector is wired pin-1 negative (−), pin-4 positive (+). Pin-2 (−) and pin-3 (+) are used to charge the removable Li-ion battery. DC ground at both pins-1 and 2 is at the same potential as chassis and signal ground.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Back Panel Descriptions

1) Security Slot

Compatible with the Kensington® Security Slot specification. Useful for securing the recorder to a fixed object with a compatible computer lock.

2) CompactFlash Slot

Accepts CompactFlash medium with the

label-side up. Compatible with Type I,

Type II, and MicroDrives.

3) Battery Mount

Accepts Sony® InfoLithium L- or M- Series batteries. Also accepts batteries conforming to this mount. Numerous capacities, from 1500 mAh to 7000 mAh are available.

4) Battery Release Pin

Push down the pin with a long skinny object such as a key, screwdriver, or a pen. With the pin pushed in, slide the L- or M-Series battery to the right to release the battery.

744T User Guide and Technical Information

Input Setup and Control

The 744T has four inputs and four record tracks. Inputs can be analog or digital sources. Analog inputs 1 and 2 use XLR connectors; inputs 3 and 4 use TA3 connections. Digital inputs can be either AES3 (balanced at the XLR) or AES3id (on BNC) inputs.

One analog pair and one digital pair can be used simultaneously.

Input Source Selection

Input sources are selected in pairs, 1, 2 and 3, 4. Each input pair (1, 2 and 3, 4) accepts analog or digital audio. The input signal type is selected using slide switch above the XLR input connector. The setup menu has additional input control.

Manually selecting the audio source is used to force the inputs to analog while using an AES3 or AES3id input to lock the 744T to an external sampling rate.

Digital sources connected to AES3id BNC inputs override analog signals on the corresponding XLR input. The BNC input signal type is set in the menu settings INPUT1,2:SOURCE and

INPUT3,4:SOURCE. For most situations the appropriate setting is auto select—the 744T will choose the input type based on signal present.

The 744T is capable of off-speed sampling rates when clocked from either external digital inputs or the word clock input.

Input sources can be set to “disabled (power save)”. This option shuts down all circuitry associated with an input pair to reduce power draw and extend battery runtime. When an input pair is disabled, the digital input LEDs associated with the pair will slowly flash. In playback-only applications, both input pairs can be shut down to maximize power-efficiency and battery runtime.

Analog Inputs 1 and 2

Analog inputs 1 and 2, on XLR connectors, are the primary connections into the recorder. These inputs accept balanced or unbalanced micor line-level inputs. When at mic-level, gain is controlled by the front panel potentiometers. Gain for the line level inputs can be controlled by the front panel potentiometers or menu settings. Line input gain is controlled in 0.1 dB steps.

A digital input present on the BNC inputs will override an analog signal present on the XLR inputs unless the input source is set to analog in the setup menu.

In the setup menu, the following functions can be controlled for analog inputs 1 and 2:

Phantom Power

Phantom power (48 volts) can be activated for inputs 1 and 2. When active, phantom is indicated by front panel LEDs ().

Phantom power is available for both micand line-level inputs. Using line-level inputs with microphones is useful in high SPL environments such as concert recording. Make certain to turn off phantom power with line level output devices susceptible to damage from DC.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Shortcut: To toggle phantom power without entering the menus, press and hold the tone key then press the menu key for channel 1. Channel 2 phantom can be toggled by pressing the tone key then pressing the HDD key. If the inputs are in line level mode, phantom power will not activate from the shortcut keys and must be activated from the menus. Phantom power is linked when the inputs are linked. (See Input Linking)

Input Limiters (mic-level only)

Microphone inputs 1 and 2 each have a limiter circuit designed to prevent input overload. In normal operation, with proper gain settings, the limiters should rarely engage. When activated, these limiters will prevent unusually high input signal levels from clipping the analog input stage of the preamp. The front panel LIM LED () shows that the limiter is engaged. Limiter activity is

indicated by additional front panel LEDs, one for each input channel (). The input limiters are active only with mic-level inputs. The limiters are engaged by (factory) default.

When limiters are engaged, audio on channels 1 and 2 is limited to −6 dBFS.

Microphone Level Control

Microphone gain is controlled by the front panel recessed knobs. The gain control adjusts an analog gain stage and functions similarly to the input trim on a mixing console or stand-alone microphone preamplifier. Gain is controllable over two ranges, normal and low.

Gain Range (microphone-level only)

The microphone inputs operate in four gain ranges, NORMAL, NORMAL FADES TO OFF, LOW, and LOW FADES TO OFF. The NORMAL range controls input gain from 24.3 dB to 67.4 dB of gain.

The LOW range controls input gain from 9.3 dB to 52.4 dB. The LOW ranges are useful for high

SPL recording environments. The fade to off options allow for fader-like control of your gain. NORMAL FADES TO OFF provides a gain range of off or 0 to 67.4 dB and LOW FADES TO OFF pro-

vides a gain range of off or 0 to 52.4 dB.

High-Pass Filters (microphone-level only)

The high pass filters on the microphone inputs use a combination of analog and digital filters to reduce sensitivity to low frequency signals. When the high-pass is engaged on an input, its front-panel LED illuminates to indicate it is active ( ). The first pole of the high-pass circuit is an analog filter at 40 Hz, 6 dB per octave and is part of the microphone preamplifier circuit. Additional poles of high-pass filtering are done in DSP.

Several frequency and slope combinations are selectable, including corner frequencies of 40, 80, 160, or 240 Hz, and filter slopes of 12 dB, 18 dB, or 24 dB per octave. The high-pass is selected for each input independently.

Shortcut: The filters can be toggled with a two-key combination. Press and hold the LCD backlight key and press the menu key for channel 1 high-pass. Press and hold the LCD backlight key and press the HDD key to toggle channel 2 high-pass. The high pass filters are linked when the inputs are linked. (See Input Linking)

Line-Level Gain Control

When in line-level position, the gain for inputs 1 and 2 is controlled by the front panel recessed

potentiometers or by a menu sensitivity setting. When set for front panel control in the user menu, LINEINPUT1:GAIN and LINEINPUT2:GAIN controls in the user menu are lined out and not acces-

sible.

744T User Guide and Technical Information

Input Linking (Stereo or MS Decoding)

Analog inputs 1 and 2 can be linked as a stereo pair. When linked, the channel 1 front panel potentiometer controls the signal level of both inputs, and the channel 2 pot controls the left-to-right balance of the pair. When the inputs are linked, their peak limiters are linked, as well.

When set to link as an MS pair, the inputs are decoded as left/right stereo, where the gain and balance for the pair work the same as stereo linking above. Input 1 is for Mid signal, input 2 for Side signal.

When the inputs are linked, phantom power and the high pass filters also act as linked pairs. Engaging and disengaging phantom power or the high pass filters on input one will force the same function upon input two. Engaging or disengaging phantom power or the high pass filter on input two causes no effect on input one.

If MS stereo linking is selected for inputs, program sent to tracks and headphones will be L/R stereo program. To record discrete M and S signals, do not link for MS, but monitor the MS signal in headphones.

Things to consider when Linking Input 1,2 as MS:

•Digital Inputs cannot be linked as an MS pair.

•If linking Line Inputs as an MS pair, the Setup Menu option LINE INPUT 1,2: GAIN CTRL must be set to Use Front Panel Knobs.

Analog Inputs 3 & 4

Appearing on Switchcraft TA3 connectors, inputs 3 and 4 accept balanced or unbalanced linelevel signals. These inputs have few controls and are typically fed from the output of a mixer or preamplifier.

Gain (sensitivity) for inputs 3 & 4 is controlled in the setup menu. Gain resolution is in 0.1 dB increments.

Analog Line Input Sensitivity

Input level sensitivity for the line-level inputs is adjustable, in 0.1 dB steps, from –6 dBu to +18 dBu. While adjusting the input sensitivity, the meters will show the relative signal level present on each input on the meters.

While channel 1 and 2 levels can be controlled by either the menu settings or the front panel pots, channels 3 and 4 are adjusted only in the setup menu.

Digital Inputs – AES3

The 744T accepts AES3 (AES/EBU) balanced digital at the XLR connectors. Digital inputs are in pairs—AES3 signals on XLR-1 appear at inputs 1 and 2, AES3 signals input to XLR-2 appear at inputs 3 and 4. To use the AES3 inputs, the input mode-select switch must be set to AES/EBU.

The front panel digital input LEDs will illuminate when digital input is selected for the indicated track(s). If the LED is flashing, digital input is selected but a no valid digital clock is received.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Digital Inputs – AES3id (S/PDIF)

The 744T accepts AES3id and S/PDIF unbalanced digital signals at the BNC connectors. The 744T will auto detect the type of digital signal and adjust accordingly. Input signals are in pairs, signals on BNC 1 appear at inputs 1 and 2, signals on BNC 2 appear at inputs 3 and 4.

AES3id inputs override analog signals present at the XLR inputs. To input analog audio while using the AES3id signal as a digital clock source, you must select analog in the input source menu selection for the appropriate inputs.

When a digital signal is present, the 744T will lock its sampling rate to the source frequency. This is indicated by a highlighted block on the main LCD display to the right of the bit depth and sampling rate indicators. Recording bit depth is not affected by the external digital source.

If you are locking the 744T to an external digital signal, be certain the source is stable. Loss of the digital signal will cause the 744T to revert to its internally set sampling rate, even while recording. The portion of the file recorded after the loss of signal may not play back properly. Once recording has begun, unused digital inputs are muted, digital signals that appear on them after the record key has been pressed will not be recorded or affect the sampling rate of the 744T.

The 744T clocks itself to the first digital signal presented to it. If the 744T detects a digital signal on the BNC inputs and locks to that signal, a digital signal applied to the XLR input will be ignored until the first digital signal is removed.

Signal Presence and Peak Indicator

The four signal presence and peak indicators show audio activity before input-to-track routing. Input signal presence LED’s illuminate when a –50 dBFS or greater signal is present. Input signal peak LEDs illuminate when signal levels reach –3 dBFS or greater.

Input Delay

A digital delay is selectable on each channel of the 744T. Delay time per input is selectable in tenths of a millisecond (0.1 msec) steps. The Rotary Switch and menu arrows are accelerated. The more you press or spin, the faster the time setting will increase or decrease. Delay is not set until the Rotary Switch is pressed or or the check mark is selected. The amount of delay available is dependent on the sampling frequency in use.

Sample Frequency	Maximum Amount of Delay Available (per input)

32, 44.1, 47.952, 48, 48.048 kHz	30 mS

88.2, 96, 96.096 kHz	15 mS

176.4, 192 kHz	7.5 mS

Input delay can be useful for time aligning input signals from differing sources. For example, digital wireless mics that have a processing delay in their outputs. In addition, all digital conversion stages have delay.

744T User Guide and Technical Information

Input-to-Track Routing

The 744T uses a flexible routing scheme to assign inputs and tracks for recording. The input matrix allows any input to be routed to any recording track. Multiple inputs can be routed to a single track to create mono-mixed recordings.

The 4-by-4 blue LED matrix makes it easy to view the set routing. A solid blue LED indicates an input is assigned to a record track.

any combination of

the four inputs can be routed to any of the four tracks

Pressing the INPUT key brings up the following menu.

Routing

Hold down the STOP key then press the key to cycle through the six preset input-to-track rout-

ing combinations. These presets are factory set and cannot be changed. The last three preset selections are CUSTOMROUTE options. Press the EDIT soft key to enter the custom routing menu. Custom

routing allows any input to be assigned to any record track. In the menu, highlighted input and track combination are displayed in white text. The four inputs are shown on the left; the four record tracks are shown on the right.

To assign custom input routings:

1.Press the input key until INPUTROUTING is displayed on the LCD display.

arrow indicates highlighted input is assigned to highlighted track

select to exit menu and apply selected routing

selet to move up

and down menu select to remove input assignment

2.Press the EDIT soft button () and scroll to the appropriate input screen.

3.Using either the Rotary Switch or the up and down arrows, navigate to desired input-to-track combinations.

4.When a chosen pairing is highlighted press either the ASSIGN soft key or the Rotary Switch to assign the combination. Assigned tracks are noted on the screen by the addition of an arrow pointing to the record track. The LED routing matrix will also show a flashing blue LED for the currently selected input-to- track combination.

5.Once a track is assigned move to the next input-to-track combination desired.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

6.To remove an input-to-track combination assignment, navigate that combination and press the UNASSIGN soft key or Rotary Switch.

7.Exit and complete the assignment by pressing the check mark soft key.

The input routing menu will always exit to the main screen whether entered from the input key or the menu selection.

Selective Input Muting

When the INPUT key is pressed, individual input muting is available. This feature can be used to quickly mute microphones while maintaining their respective track assignments.

Indicates that an input is available for routing.

No indication here shows that an input is muted.

A solidly lit input Peak LED indicates that an input is muted.

A solid illuminated Peak LED indicates that an input is muted

Monoand polyphonic files behave differently when selective muting is applied When monophonic files are selected, files from tracks A, B, C, and D are named with the suffix “_1, _2, _3, and _4” respectively. If, for instance, track B is muted but tracks A, C, and D are still selected, the resulting files will be named “_1, _3, and _4” and track B will not be recorded, saving storage space.

When polyphonic files are selected a four track file will be generated with track B being a blank track. Blank tracks in polyphonic files take up the same amount of storage space as tracks that are assigned.

Sampling Rate and Bit Depth

When recording the 744T generates uncompressed PCM audio WAV files in the Broadcast Wave File format at the user-selected sampling rate and bit depth. The 744T LCD calculates available recording time based on the sampling rate, bit depth, number of tracks set for recording and the selected storage media available capacity. See the Calculating Recording Time later in this guide to estimate record time.

Sampling Rate

When a sampling rate is selected for recording, all tracks are recorded at the selected sampling rate. Sampling rates are selected among common rates from 32 kHz to 192 kHz. Additionally, nonstandard sampling rates can be applied when the 744T is word clocked from an external source (clock sources between 32 kHz and 192 kHz). When recording off-speed sampling rates files will be stamped with the rate closest to an internally generated frequency.

744T User Guide and Technical Information

Relationship Between Sampling Frequency and Audio Bandwidth

The sampling frequency is expressed in samples per second (in hertz) and defines the number of times in a second that the analog audio signal has been measured. Sampling frequency determines the audio bandwidth, or frequency response, that can be represented by the digital signal. A quick estimate of the maximum bandwidth capable of being represented at a given sampling rate is maximum analog frequency = sampling frequency/2. Higher sampling frequencies allow for wider audio bandwidth.

The 744T generates the following sampling rates:
• 32 kHz	• 88.2 kHz
• 44.1 kHz	• 96 kHz
• 47.952 kHz	• 96.096 kHz
• 47.952kF - file stamped at 48 kHz	• 96.096kF - file stamped at 96 kHz
• 48 kHz	• 176.4 kHz
• 48.048 kHz	• 192 kHz
• 48.048kF -file stamped at 48 kHz

See Time Code section for more information about the 48.048F, 47.952F, and 96.096F rates.

Bit Depths

The 744T records at bit depths of either 16 or 24 bit. 24 bit recording provides greater dynamic range and addition headroom for signal peaks relative to 16 bit recordings. 24 bit recording (versus 16 bit) is a significant benefit for field production audio tracks.

Bit Depth = Available Dynamic Range

Bit depth defines the digital “word length” used to represent a given sample. Bit depth correlates to the maximum dynamic range that can be represented by the digital signal. Larger bit depths accommodate more dynamic range. A quick estimate of maximum dynamic range capable of being represented by a given word length is dynamic range ~= no. of bits x 6 dB. Bit depth is an exponential measure (exponent of 2), so as bit depth increases, the amount of data it represents increases exponentially. The majority of field recording is done with 16-bit audio, therefore, each sample is represented by a digital word of 2^16 (65,536) possible values. 24-bit audio has a word length of 2^24 (16.7 million) possible values per sample.

The 744T has 24 bit analog-to-digital converters. To obtain 16 bit recording the 744T can be set to dither 24 bit digital signals to 16 bit. The 744T uses a proprietary pseudo-random dither routine for accurate bit rate reduction. Dither can be defeated in the user menu. Without dither, 24 bit audio is truncated to 16 bit, meaning the least significant 8 bits are discarded.

Once a file is recorded its sampling rate and bit depth can not be changed in the recorder. The 744T does not perform sample rate conversion or bit depth changes. File conversion must be done in another environment, such as an audio workstation. Alternatively, a real-time analog transfer is often performed instead of sample rate conversion.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Word Clock

A stable word clock source is essential for high quality digital audio. The 744T uses a rock-stable time code crystal to generate its internal word clock frequencies. The 744T can clock external devices from its word clock and accept and lock to external clock sources for recording.

The 744T disregards external clock, both AES and word clock, during playback.

Clock Master

When sending digital audio to several devices, one unit is designated as the word clock master and the others as slaves. Generally, the device with the analog-to-digital converter is designated as the word clock master.

The 744T can function as an A/D converter and can be used as the master word clock source. Slaved digital devices derive their word clock timing from either their digital audio inputs, S/PDIF or AES/ EBU, or through their word clock input connection. As a word clock master the 744T generates word clock whether or not audio is sent. If devices use separate word clock sources unpredictable behavior will result.

Clock Slave

When connecting digital audio sources to the 744T inputs, the recorder will derive its clock signal from the AES (S/PDIF) stream. It will slave to the external device. If, for example, you are using a wireless receiver with a digital output, it may not have an external word clock input, and will be the word clock master.

If digital audio is connected to the 744T from more than one digital device, you must word clock theses sources together, otherwise variations between the sources will render their signals unusable.

If the 744T is slaved to external word clock, be certain that the source is stable. Loss of the word clock signal during recording can cause the 744T to revert back to its internally set sampling frequency.

If this occurs, the portion of the file recorded after the loss of word clock may not play back at the proper speed. For reliability, we recommend you set the 744T to the same sample frequency as the word clock source. Loss of the word clock signal in this case will most likely cause a glitch in the file, but the file may still be usable.

Multi-Unit Linking Via C. Link

The proprietary C. Link (control link) connection enables multiple 744T, 722, 702T, and 702 recorders to be connected for recordings requiring high track counts. C. Link also enables connection to the CL-1 Remote Control and Keyboard Interface.

When linked, the 7-Series recorders have a master/slave relationship. The master recorder and the slave unit will share sample accurate start and stop record times. Multiple units can be daisy-chained together to record nearly unlimited tracks. The C. Link protocol links carries the following data:

•word clock

•time code information (744T, 702T only)

•RS-232 machine transport data

744T User Guide and Technical Information

master	slave	slave
unit	unit	unit

To link units:

1. Connect multiple units as shown in the illustration above.

2.Set all linked recorders to the same sampling rate, bit depth, file format, and time code frame rate (if used). This will ensure that all files generated are compatible.

3.If time code is being used, set slave units to External time code mode so that they will follow the master recorder’s time code generator.

4.Set scene names on each of the units for easy identification in post production. Take numbers should be set to the same on all linked recorders if take numbers are reset before recording. There is no file name synchronization with multiple unit linking.

When linked, record start and stop on slave units will not affect units “above” in the linked chain. This makes it possible for units to get out of synchronization if a unit other than the master is set to record or stop. Using the master unit will assure that all machines begin and end recording together.

Master/Slave relationships between C.Linked recorders is established immediately after the C.Link Out to C.Link In connection is made. To reverse the Master/Slave relationship, power down all recorders, establish the new Master/Slave relationships by reconnecting the C.Link Out to C.Link In connectors in the desired sequence, then power on all units in order of their Master/Slave relationships.

The master recorder in a C.Link connection can not receive wordclock sync from anywhere else. It must be the master wordclock source for all C.Link slaves.

The C. Link jack is a proprietary RS-232 port. Under no circumstances should analog or digital telephone lines be connected to either jack. Serious damage to the recorder could result.

Outputs – Analog and Digital

The 744T has two two-channel output buses, the Master Output Bus and Output Bus 2. Each of these buses is assigned audio sources independently, enabling the 744T to feed multiple outputs with unique program.

The chart below shows the audio sources available for the each channel of the Master Output Bus and Output Bus 2 connections. The audio sources for each output bus are selected in the Setup Menu.

v. 2.67 Features and specifications are subject to change. Visit www.sounddevices.com for the latest documentation.

Available Output Sources		Description

Input 1	Inputs are assignable for each channel of the output bus.
Input 2
Input 2	When inputs are selected as the source for the outputs, the state of recording or playback activity has no
Input 3
Input 3	effect on the output signal. This allow uninterrupted audio at the outputs.
Input 4
Input 4

Track A
Track B
Track C
Track D
Input 1,2	Multiple inputs are summed with these selections.
Input 3,4
Input 1,3
Input 2,4
Input 1,2,3
Input 2,3,4
Input 1,2,3,4
Track A,B	Multiple track assignments are summed with these selections.
Track C,D
Track A,C
Track B,D
Track A,B,C
Track B,C,D
Track A,B,C,D

Master Output Bus

Audio signals routed to the Master Output Bus are sent to three output connections:

•analog line out, 2 x TA3, two-channel

•analog tape out, 3.5 mm TRS, two-channel

•digital 1, AES3id, BNC connection, two-channel

Analog Line Out L, R

The analog line outputs are active-balanced line-level signals on Switchcraft TA3M locking connectors. The output level is a nominally 0 dBu at −20 dBFS. The level of the line output can be attenuated in the setup menu by up to 40 dB in 1 dB increments. Attenuation is done as an output pair.

Analog Tape Output

The tape output connection is stereo, unbalanced consumer output level (–10 dBV) on a TRS 3.5 mm connector. Output attenuation affects this output level.

Digital AES3id Output

The unbalanced AES3id output is directly compatible with most S/PDIF inputs.

The format for the AES3id output is selectable between professional AES and SPDIF. In either case the SCMS bit is not set.

Attenuation to the Master Output Bus affects both analog and digital signals.

Output Bus 2

Just as with the Master Output Bus, Output Bus 2 can be assigned signal sources from inputs or tracks. Sources assigned to Output Bus 2 are exclusive and do not affect the assignments to the Master Output Bus or headphone assignments. The same signal sources available for the Master Output Bus are available for Output Bus 2 (see chart above).

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