Steinberg Cubase LE Operation Manual

							CUBASE LEVST System Link 25 – 471
Setting up clock sync
Before you proceed, you need to make sure that the clock signals on 
your ASIO cards are synchronized correctly. This is essential when 
cabling any kind of digital audio system, not just VST System Link.
❐All digital audio cables by definition always carry a clock signal as well as 
audio signals, so you dont need to use a special Word Clock input and 
output for this (although you may find that you get a slightly more stable 
audio system if you do, especially when using multiple computers).
The Clock Mode or Sync Mode is set up in the audio hardware’s 
ASIO Control Panel. In Cubase LE, you proceed as follows:
1.Pull down the Devices menu and open the Device Setup dialog.
2.Select the VST Multitrack device and make sure the Setup tab is se-
lected to the right.
3.Click the Control Panel button.
The ASIO Control Panel appears.
4.Open the ASIO Control Panel on the other computer as well.
If you are using another VST System Link host application on that computer, check its 
documentation for details on how to open the ASIO Control Panel. Hint: in Steinberg’s 
Nuendo 1.6 (or higher), the procedure is the same as in Cubase LE. In Cubase 5.2, 
you pull down the Options menu, select System from the Audio Setup menu and click 
the Control Panel button in the Audio System Setup dialog that appears. 
						

							CUBASE LE25 – 472 VST System Link
5.Now, you need to make sure that one audio card (and only one!) is set 
to be the Clock Master, and all the other cards must be set to listen 
for the clock signal coming from the Clock Master i.e. they must be 
Clock Slaves.
The naming and procedure for this differs depending on the audio hardware – consult 
its documentation if required. If you are using Steinberg Nuendo ASIO hardware, all 
cards default to the “AutoSync” setting – in this case you must set one of the cards 
(and only one) to “Master” in the Clock Mode section of the Control Panel.
•Typically, the ASIO Control Panel for an audio card contains some in-
dication of whether the card receives a proper sync signal or not, and 
the sample rate of that signal.
This is a good indication that you have connected the cards and set up clock sync 
properly. Check your audio hardware’s documentation for details.
❐It’s very important that one and only one card is the clock master, other-
wise the network cannot function correctly. Once you have set this up, all 
the other cards in the network will take their clock signal from this card 
automatically.
The only exception to this procedure is if you are using an external 
clock – which could be from a digital mixing desk or special Word 
Clock synchronizer for example. If so, you must then leave all your 
ASIO cards in Clock Slave or AutoSync mode, and make sure that 
each of them is listening for the signal coming from the synchronizer, 
usually passed through your ADAT cables or Word Clock connectors 
in a daisy chain fashion. 
						

							CUBASE LEVST System Link 25 – 473
Minimizing the latency
The general definition of latency is the amount of time it takes any sys-
tem to respond to whatever messages are sent to it. For example, if 
your system’s latency is high and you play VST instruments in real 
time, you will get a noticeable delay between when you press a key 
and when you hear the sound of the VST instrument. Nowadays, most 
ASIO-compatible audio cards are capable of operating with very low 
latencies. Also, all VST applications are designed to compensate for 
latency during playback, making the playback timing tight.
However, the latency time of a VST System Link network is the total 
latency of all the ASIO cards in the system added together. Therefore 
it’s extra important to minimize the latency times for each computer in 
the network.
• The latency does not affect the synchronization – its always perfectly in 
time. But, it can affect the time it takes to send and receive MIDI and au-
dio signals, or make the system seem sluggish.
To adjust the latency of a system, you typically adjust the size of the 
buffers in the ASIO Control Panel – the lower the buffer size, the lower 
the latency. Generally speaking its best to keep to fairly low latencies 
(buffer sizes) if your system can handle it – about 12 ms or less is usu-
ally a good idea. 
						

							CUBASE LE25 – 474 VST System Link
Setting up your software
Now it’s time to set up your programs. The procedures below de-
scribe how to set things up in Cubase LE; if you are using another 
program on the other computer, please refer to its documentation.
Setting the sample rate
The projects in both programs must be set to use the same sample 
rate. Select “Project Setup…” from the Project menu and make sure 
the sample rate is the same in both systems.
Setting up inputs and outputs
1.Open the VST Inputs window from the Devices menu.
2.Activate the inputs you want to use by clicking the buttons in the Ac-
tive column.
To make it simple you will probably want to enable all inputs available in the cable you 
are using. For example, if you are using an ADAT connection this would mean clicking 
on the first four buttons (i.e. activate the first eight inputs). 
						

							CUBASE LEVST System Link 25 – 475
3.Close the VST Inputs window and open the VST Outputs window 
from the Devices menu.
4.Enable the output buses you need.
Usually these should match up to the input buses you enabled above. In our ADAT 
example, this would mean the first four stereo outputs.
5.Repeat the steps above for all computers in the network. 
• Note that at least one computer in your network needs to have more 
than one physical set of audio outputs, so that you can hear whats com-
ing out of it!
For example, if your audio card has a stereo analog out and an ADAT connector, you 
can use the ADAT connector for networking and the analog outs for monitoring. Make 
sure that the bus setup in your VST application reflects which set of outputs is doing 
which operation.
Once weve done this we have a set of inputs and outputs that can 
carry both our network commands and audio signals from one com-
puter to another. At this point, it may be a good idea to test that every-
thing is set up properly: 
						

							CUBASE LE25 – 476 VST System Link
Streaming digital audio between applications
1.Set things up so that Computer 1 plays back some audio.
You could for example import an audio file and play this back in Cycle mode.
2.In the Mixer, make sure the playing audio channel is routed to one of 
the digital outputs you have set up for the VST System Link connection.
3.In Computer 2, select the corresponding digital input for an audio 
channel and activate monitoring for the channel.
The audio being played back should now “appear” in the program running on Com-
puter 2. You should now see the input level meters moving, and hear the audio.
4.Reverse this procedure so that Computer 2 plays back and Computer 
1 “listens”.
Now you have verified that the digital connection works as it should. 
						

							CUBASE LEVST System Link 25 – 477
Activating VST System Link
After setting up the inputs and outputs, you now need to define which 
input/output should carry the actual VST System Link information.
The System Link networking signal is carried on only one bit of one 
channel. This means that if you have an ADAT based system which 
normally carries eight channels of 24-bit audio, once you activate VST 
System Link you will have seven channels of 24-bit audio and one 
channel of 23-bit audio (the least significant bit of this last channel is 
what we will use for networking). In practice this makes no discernible 
difference to the audio quality, since you will still have around 138dB 
headroom on this channel.
To set things up we need to open the VST System Link panel:
1.Open the Device Setup dialog on the Devices menu.
2.Select the VST System Link device and make sure the Setup tab is 
selected to the right.
3.Use the ASIO Input and ASIO Output pop-up menus to define which 
channel should be the networking channel (and thus become a 23-bit 
audio channel, in our example).
Quite often you will be able to just leave these pop-ups the way they are.  
						

							CUBASE LE25 – 478 VST System Link
4.Click the Active checkbox at the top of the panel.
5.Repeat the steps above for every computer on the network. 
As the computers are made active, you should see the small T (Trans-
mit) and R (Receive) lights flashing on each active computer, and the 
name of each computer should appear in the list at the bottom of the 
pane. Each computer is assigned a random number – dont worry 
about this, its just so the network knows internally which one is which.
•You can double click on the name in bold (which is the name of the 
computer you’re currently working on) and set it to whatever other 
name you wish.
This name will appear in the System Link window of every computer on the network.
• If you dont see the name of each computer appearing once you have 
made it active, you may have to check your settings. 
Go through the procedure above again and make sure that all ASIO cards are listening 
to the digital clock signals correctly, and that each computer has the correct inputs 
and outputs assigned to the System Link network.
Putting the network online
After each computers name you will see whether it is online or not. 
When a computer is online, that means it receives transport and time-
code signals, and its sequencer application can be started and stopped 
by remote control. If it is off-line it can only be started from its own key-
board – it is effectively an independent machine, although it is still on 
the network.
• Note that any computer can control any and all of the others – VST Sys-
tem Link is a peer to peer network and there is no absolute “master” 
computer.
However, most users do like to think of one machine as the master (in a one person / 
two computer network, this would be the machine you actually sit behind most of the 
time).  
						

							CUBASE LEVST System Link 25 – 479
For now, lets put all computers online:
1.Activate the Online checkbox in the VST System Link panel for all 
computers. 
2.Check that the system is working by pressing Play on one computer – 
all computers should start almost instantly and play perfectly in time, 
with sample accurate precision. 
•The Offset setting to the right allows you to adjust whether one ma-
chine will play back slightly ahead or behind the rest.
This is normally not needed, but occasionally with some hardware you may find that the 
lock is a few samples out. In that case you can adjust the lock with the Offset value. For 
now, leave it set to 0 – it will most likely be what you want.
VST System Link sends and understands all transport commands, so 
you can play, stop, fast forward, rewind etc. the entire network from 
one computer without a problem – try it! If you jump to a locator point 
on one machine, all other machines will also instantly jump to that lo-
cator point.
❐Dont forget to make sure that all computers have their tempos set to the 
same value, otherwise your synchronization will be seriously skewed. 
						

							CUBASE LE25 – 480 VST System Link
Using MIDI
As well as supplying transport and sync control, VST System Link also 
supplies up to 16 MIDI ports, each with 16 channels. You set this up 
as follows:
1.Use the MIDI Ins and Outs value boxes to specify the number of MIDI 
ports you need.
The default value is 0 MIDI In and 0 MIDI Out ports.
2.Create a MIDI track in the Project window and open the Inspector 
(top section).
3.If you now pull down the “in” or “out” pop-ups, you will find the speci-
fied System Link ports added to the list of MIDI Inputs and Outputs.
This allows you to route MIDI tracks to VST instruments running on 
another computer, as described in the application examples (see 
page 484).