Steinberg Nuendo 3 Operation Manual

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Timecode, MIDI clock and word clock
Basically there are three types of synchronization signals for audio: 
timecode, MIDI clock and word clock.
Timecode (SMPTE, EBU, MTC, VITC etc.)
Timecode appears in a number of guises. No matter which “format” it 
has, it always supplies a “clock on the wall” type of synchronization, 
that is, a synchronization related to hours, minutes, seconds and two 
smaller units called “frames” and “subframes”.
• LTC (SMPTE, EBU) is the audio version of timecode. This means that it can 
be recorded on the audio track of an audio or video recorder.
• VITC is the video format timecode, that is it is stored in the actual video image.
• MTC is the MIDI version of timecode, transmitted in MIDI cables.
• ADAT sync (Alesis) is only used with the ASIO Positioning Protocol, see page 
575.
• Sony 9-pin is a standard that uses serial (RS-422) communication. Sony 9-
Pin contains timecode as well as machine control messages (see page 588).
For the ASIO Positioning Protocol, other high precision timecode for-
mats may also be supported.
Format recommendations for timecode – without ASIO Positioning 
Protocol
• When synchronizing your system to external timecode, via a synchronizer, the 
most common timecode format is MTC. Contrary to some reports you might 
have heard, MTC delivers good precision for external sync. This is due to the 
fact that the operating system can “time stamp” incoming MIDI messages, 
which increases precision.
• Sony 9-Pin is not recommended for external sync and should only be used 
when no other option is available. However, you might of course use 9-Pin for 
machine control, see page 577.
Format recommendations for timecode – with ASIO Positioning Protocol
• LTC and VITC are the formats with the highest precision and are recommended 
when available.
• MTC is the next best option and probably the most common choice, since few 
audio hardware solutions have built in LTC or VITC readers. However, LTC 
and VITC offer even higher precision when available.
• The choice with the least precision is Sony 9-Pin. 
						

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MIDI Clock
MIDI Clock is a tempo based type of synchronization signal, that is it is 
related to the number of “beats per minute”. MIDI Clock signals are 
suitable for synchronizing two devices that agree on tempo, such as 
for example Nuendo and a drum machine.
MIDI Clock is not suitable as a master sync source for an application 
like Nuendo. Therefore Nuendo will transmit MIDI Clock signals to other 
devices, but it will not receive MIDI Clock.
Word Clock
Word clock is basically a replacement for the sample rate clock in for 
example an audio card. Word clock hence runs at the same rate as 
the sample rate in the audio, 44.1kHz, 48kHz etc.
Word clock does not contain any position information, it is only a 
“simple” signal for clocking the audio at its sample rate.
Word clock comes in many formats, analog on coaxial cable, digital as 
part of an S/PDIF, AES/EBU or ADAT audio signal, etc.
Synchronizing the transport vs. synchronizing audio
How timing is handled in a non-synchronized system
Let’s first look at the situation where Nuendo is not synchronized to 
any external source.
Any digital playback system has an internal clock that ultimately af-
fects the playback speed and stability, and PC audio hardware is no 
exception. This clock is extremely stable.
When Nuendo is playing back with no external synchronization, all 
playback is internally synchronized to the internal digital audio clock, 
to ensure synchronization between digital audio and MIDI. 
						

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Synchronizing Nuendo’s playback
Let’s assume now that we use external timecode synchronization, with 
Nuendo. For example, we might synchronize playback to a tape re-
corder.
Timecode coming from an analog tape recorder will always vary slightly 
in speed. Different timecode generators and different tape recorders 
will also supply timecode with slight differences in speed. In addition, 
the shuttling of tape mechanisms due to overdubs and re-recordings 
can cause the physical tape to wear and stretch, which affects the 
speed of the timecode.
If you set up Nuendo to sync to incoming timecode, it will vary its over-
all playback speed to compensate for such fluctuations in the speed 
of the timecode – that’s the whole purpose of synchronization.
What happens with the digital audio?
The fact that Nuendo’s playback is synchronized to the timecode 
does not affect the playback of the digital audio. It still relies on the 
perfectly stable, built-in clock in the audio hardware.
As you may understand by now, problems will appear when the per-
fectly stable digital audio gets related to the slightly varying speed of a 
system synchronized to timecode.
The playback timing of each event will not be in total accordance with 
the tape or the MIDI playback, since the playback speed of the audio 
is determined by the digital audio hardware’s built-in clock.
Resolving to word clock
The solution to this problem is to use one external clock for all compo-
nents in the system. One master clock is used to derive whatever type 
of clock signal each component in the system needs. For example, 
something called a house clock can be used to generate sample rate 
clocks for the digital audio hardware and timecode for Nuendo. This 
ensures all components in the system use the same reference source 
for their timing.
Synchronizing digital audio to external clocks running at sample rate is 
often called “resolving” or “synchronizing to word clock”.  
						

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If you aim to perform synchronization to external signals, we strongly 
recommend that you obtain proper synchronization equipment. This 
encompasses:
• An audio card that can be slaved to external word clock.
• A synchronizer that can read timecode (and possibly house clock) and gener-
ate the required sync signals from that, such as the Steinberg TimeLock Pro.
or...
• An audio system with complete built-in synchronization possibilities, prefera-
bly supporting the ASIO Positioning Protocol.
Using timecode without word clock
Of course, it is possible to set up a synchronization system where you 
lock Nuendo to timecode without using word clock. However, please 
note that the timing of audio vs. MIDI cannot be guaranteed and that 
fluctuations in speed in the incoming timecode will not affect the play-
back of audio events. This means that synchronizing to timecode may 
work in the following situations:
•When the timecode was originally generated by the audio card itself.
•When the source providing the timecode is extremely stable (such as 
a digital video system, a digital tape recorder or another computer).
•When you remain synchronized to that same stable source through-
out the entire process, both while recording and playing back audio. 
						

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About the ASIO Positioning Protocol (APP)
ASIO Positioning Protocol requires audio hardware with specific ASIO 
drivers. As of this writing, APP is not available for audio hardware with 
non-ASIO drivers under Mac OS X.
The ASIO Positioning Protocol is a technology that expands on the 
type of sync described above and makes sample accurate positioning 
possible.
When transferring audio digitally between devices, it is important that 
synchronization using word clock and timecode is completely corre-
lated. If not, the audio will not be recorded at the exact intended (sam-
ple accurate) position, which can cause various types of problems, 
such as inaccurately positioned audio material, clicks and pops etc.
A typical situation is when transferring material from a digital multi-
track tape recorder to Nuendo (for editing) and then back again. If you 
do not have sample accurate synchronization set up, you cannot be 
sure that the material will appear in its exact original position, when 
transferred back to the tape recorder.
In order to take advantage of the ASIO Positioning Protocol, your au-
dio hardware must be suitably equipped and the functionality must be 
included in the ASIO driver for the hardware.
An example of a system for doing sample accurate transfers, would be 
transferring audio tracks from an Alesis ADAT to Nuendo. Here the 
ADAT will be the sync master (though it doesn’t necessarily have to 
be). It provides both the digital audio (with an inherent word clock) 
and positional information (timecode) via its ADAT sync protocol. The 
master clock is generated by the ADAT itself.
Hardware and software requirements for APP
• Your computer audio hardware (in our example above this would be an ADAT 
card in your computer) must support all the functionality required for the ASIO 
Positioning Protocol. That is, it must be able to read the digital audio and the 
corresponding positional information from the external device.
• There must be an ASIO 2.0 driver for the audio hardware.
• For resolving to external timecode, the audio hardware must have a timecode 
reader/writer on-board. 
						

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• For information about which audio hardware models currently support APP, 
see the Steinberg web site (www.steinberg.net).
The ASIO Positioning Protocol exploits the specific advantage of having 
an audio card that has a built-in timecode reader. With such a card and 
the ASIO Positioning Protocol, you can achieve constant sample accu-
rate synchronization between the audio source and Nuendo.
Machine control
Nuendo can control external tape transports and similar devices via 
MIDI Machine Control or Sony 9-Pin. This allows you to operate an 
external tape transport from Nuendo’s Transport panel. That is, Nu-
endo can make the tape recorder locate to a certain position, start, 
stop, rewind etc.
About sync and machine control
Controlling tape transports is a two-way process:
• Nuendo sends out machine control commands to the tape recorder, asking it 
to locate to a certain position and activate playback etc.
• The tape recorder locates to the requested position, starts and delivers time-
code back to Nuendo, to which Nuendo is synchronized.
Even though it appears as if Nuendo is controlling the tape recorder 
completely, it is important to remember that in this setup, Nuendo is 
still being synchronized to the external tape transport, not vice versa.
Also note that the two processes of sync and machine control are 
completely separated, in terms of protocols used. You can for exam-
ple synchronize to MTC while sending out transport commands via 
MMC.
MIDI Machine Control (MMC)
This is a standard MIDI protocol for controlling tape transports. There 
are a number of tape recorders and hard disk recording systems on 
the market that support this protocol. Nuendo allows you to control 
the transport of an external MMC device and arm tracks for recording. 
						

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Sony 9-Pin
This is a standard protocol established by Sony, for controlling audio 
and video tape transports. It is implemented via regular serial port 
communication (RS-422). The correct cabling varies between com-
puter platforms and models. Please refer to page 587 to find out more 
about the correct setup for your computer.
• If your Sony 9-pin device supports RS-232, you need a “null modem cable”.
• The Sony 9-pin device most likely needs to be switched from local control to 
remote control in order to be controlled by Nuendo. If the device is not set to 
the correct mode, Nuendo will inform you. Most video decks have a switch on 
the front panel for this.
• Normally you should not lock Nuendo to timecode from the Sony 9-Pin device. 
There is timecode information in the 9-pin signal but it is primarily used for lo-
cating and shuttling. It is erratic and not stable enough to use as a timing or 
speed reference. Timecode should be read from either an LTC source or VITC 
source on a video tape machine.
• Nuendo implements Start, Stop, Record, Fast-Forward, Rewind, Shuttle, 
Nudge and Locate commands for 9-Pin devices, along with some special fea-
tures, described on page 593. 
						

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Window Overview
The Synchronization Setup dialog
This dialog box is used for setting up everything that has to do with 
Nuendo’s synchronization to other units. You reach it from the Trans-
port menu.
Settings for 
sync to exter-
nal timecode.
Options for 
incoming 
timecode.Machine Control 
Settings/
Machine Control 
Options.
Outputs for 
MIDI Clock.
Outputs for MIDI 
Timecode.
Input port for 
MIDI Timecode.  
						

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Operations
Making connections and basic settings
The descriptions below are for a basic setup with a separate synchro-
nizer and audio card. Depending on your exact situation and require-
ments for communication with external devices, there are endless 
variations on this theme. Please consult your dealer for more detailed 
recommendations.
The following connections are required for external sync via a syn-
chronizer, including resolving of the audio card. For details on audio 
card and synchronizer settings and connections, see the manuals for 
those devices.
•Route the master clock signal (LTC, VITC, etc.) to an input on the syn-
chronizer.
•Connect the word clock output on the synchronizer to a word clock 
input on the audio card.
•Connect the MIDI Timecode (MTC) or 9-Pin output on the synchronizer 
to the corresponding input on the computer.
•Set up the synchronizer and make sure the frame rate settings are in 
accordance with the master clock.
For more information on frame rates, see page 594.
A typical synchronization setup.
Synchronizer MIDI Interface Video transportMIDI TimecodeWord Clock
to audio card
LTC Timecode Audio
Amplifier and
speakers 
						

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Setting up the audio card for external synchronization
1.Open the Device Setup dialog from the Devices menu and under “VST 
Audiobay”, select the subpage with the name of your audio interface.
2.Click the Control Panel button to open the card’s proprietary setup 
dialog.
If this card is accessed via a special ASIO driver (as opposed to MME or Direct X), this 
dialog is provided by the card, not by Nuendo. Hence the settings vary with the card 
brand and model.
3.Adjust the settings as recommended by the card manufacturer, then 
close the dialog.
The dialog may also contain various diagnostic tools that allow you to verify for exam-
ple whether word clock is arriving correctly.
4.From the Clock Source pop-up, select the input to which you routed 
the word clock signal.
This pop-up may not be used if you selected an input in the Control Panel dialog instead.
Setting up Nuendo for external sync to timecode
1.In the Synchronization dialog, set Timecode Source to MIDI Timecode, 
one of the 9-Pin options or ASIO Audio Device (if your hardware is 
compatible with the ASIO Positioning Protocol).
2.For MIDI Timecode, use the MTC Input pop-up menu in the MIDI Time-
code Settings section to the right to select an input for the timecode.
If you are using the ASIO Positioning Protocol, this is not required, since the timecode 
is then coming in directly via your audio hardware.
Sync settings for MIDI Timecode.
Sync to MIDI timecode activatedThis is where you set the MIDI 
Input for the timecode