Steinberg Cubase SE 3 Operation Manual

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VST System Link 25 – 511
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 from the VST Audiobay subpage.
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.   
						

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25 – 512 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 – don't worry 
about this, it's 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 don't 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 computer's name you will see whether it is online or not. 
When a computer is online, it will receive transport and timecode 
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).  
						

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VST System Link 25 – 513
For now, let's 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.
Don't forget to make sure that all computers have their tempos set to the 
same value, otherwise your synchronization will be seriously skewed. 
						

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25 – 514 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 spec-
ified 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 518).   
						

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VST System Link 25 – 515
The “Active ASIO Ports for Data only” setting
If you are sending huge amounts of MIDI data at once, there is a small 
possibility that you might run out of bandwidth on your VST System 
Link network. This will manifest itself by notes “choking” or timing be-
coming erratic.
If this happens, you can devote more bandwidth to MIDI by selecting 
Active ASIO Ports for Data only in the VST System Link Setup panel. 
When this is active, the VST System Link information will be sent on 
the entire channel instead of just one bit, more than enough for all the 
MIDI you could ever hope to use. The downside is that you can no 
longer use this ASIO channel for audio transfer (do not connect it to a 
speaker!), thus leaving you only 7 channels of audio in our ADAT ca-
ble example. Depending on how you work this might be a reasonable 
compromise.
Hearing the network audio
If you are using an external mixing desk, hearing your audio really isn't 
an issue – just plug the outputs of each computer into the desired 
channels on the external mixing desk, press Play on one of the com-
puters, and you're good to go.
However, many people prefer to mix internally inside the computer and 
just use a desk for monitoring (or maybe not use any external mixer at 
all). In this case you'll need to select one computer to be your “main mix 
computer” and send the audio from your other computers into this.
In the following example, we assume you are using two computers, 
with Computer 1 as your main mix computer and Computer 2 running 
two additional stereo audio tracks, an FX channel track with a reverb 
plug-in and a VST instrument plug-in with stereo outputs.
1.First you want to set things up so that you can listen to the audio play-
back from Computer 1.
In other words, you need an unused set of outputs, e.g. an analog stereo output, con-
nected to your monitoring equipment.
2.Go to Computer 2 and route each of the two audio tracks to a sepa-
rate output bus.
These should be busses connected to the digital outputs – let’s call them Bus 1 and 2.
3.Route the FX channel track to another VST System Link bus (Bus 3). 
						

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4.Route the VST instrument channel to yet another bus (Bus 4).
5.Go back to Computer 1 and add four new stereo audio tracks and 
route these to the output bus you use for listening, e.g. to the analog 
stereo outputs.
6.For each of the audio tracks, select one of the four input busses.
Now, each Computer 2 bus is routed to a separate audio channel on Computer 1.
7.Activate monitoring for the four tracks.
If you now start playback, the audio from Computer 2 will be sent 
“live” to the new tracks on Computer 1, allowing you to hear them to-
gether with any tracks you play back on Computer 1.
Adding more tracks
OK, but if you have more audio tracks than you have VST System Link 
busses (physical outputs)? Then you just use the Computer 2 mixer 
as a submixer: Route several audio channels to the same output bus 
and adjust the output bus level if needed.
Note also that if your audio cards have multiple sets of input and out-
put connections you can link up e.g. multiple ADAT cables and send 
audio via any of the busses on any of the cables.
Internal mixing and latency
One problem with mixing inside the computer is the latency issue we 
mentioned earlier. The VST engine always compensates for record la-
tencies, but if you are monitoring through Computer 1 you will hear a 
processing delay while you listen to signals coming from your other 
computers (not on your recording!). If your audio card in Computer 1 
supports ASIO Direct Monitoring you should definitely turn this on – 
you'll find the setting in the VST Audiobay Device Setup panel (see 
page 45). Most modern ASIO cards support this function. If yours 
doesn't you may want to change the Offset value in the VST System 
Link Setup panel to compensate for any latency issues. 
						

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VST System Link 25 – 517
Setting up a larger network
This is not much more difficult than a two computer network. The main 
thing to remember is that VST System Link is a daisy chain system. In 
other words, the output of Computer 1 goes to the input of Computer 
2, the output of Computer 2 goes to the input of Computer 3, and so 
on around the chain. The output of the last computer in the chain must 
always go back into the input of Computer 1, to complete the ring.
Once you've done this, the transmission of all the transport, sync, and 
MIDI information to the whole network is handled pretty much automat-
ically. However, where you may run into confusion in a large network is 
in the transmission of audio signals back to a central mix computer.
If you have lots of hardware inputs and outputs on your ASIO cards you 
don't need to send audio via the chain at all, but can transmit it directly 
to the master mix computer via one or more of its other hardware Inputs. 
For example, if you have a Nuendo Digiset interface or 9652 card on 
Computer 1 you could use ADAT cable 1 for networking, ADAT cable 2 
as a direct audio input from Computer 2, and ADAT cable 3 as a direct 
audio input from Computer 3.
You can also transmit audio via the ring system if you don't have enough 
hardware I/Os for direct audio transmission. For example, in a four com-
puter scenario you could send audio from Computer 2 into a channel in 
the mixer in Computer 3, and from there to a channel in the mixer in 
Computer 4, and from there back to the master mixer in Computer 1. 
This can certainly be tricky to set up, so generally it is recommended 
that if you want to set up a complex network, you should make sure to 
use ASIO cards with at least three separate digital I/Os.  
						

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25 – 518 VST System Link
Application examples
Using one computer for VST instruments
In this example, you are using one computer as your main record and 
playback machine, and want to use another computer as a virtual 
synth rack.
1.Record a MIDI track into Computer 1.
2.Once you have finished recording, route the MIDI output of that track 
to System Link MIDI port 1.
3.Now go to Computer 2, open up the VST Instrument rack and assign 
an instrument to the first slot in the rack.
4.Route the VST Instrument channel to the desired output bus.
If you are using Computer 1 as your main mixing computer, this would be one of the 
VST System Link output busses, connected to Computer 1.
5.Create a new MIDI track in the Project window of Computer 2, and 
assign the MIDI output of the track to the VST Instrument you created. 
6.Assign the MIDI input of the track to be VST System Link port 1.
Now, the MIDI track on Computer 1 is routed to the MIDI track on Computer 2, which 
in turn is routed to the VST Instrument.
7.Now activate monitoring for the MIDI track on Computer 2, so that it 
will listen and respond to any MIDI commands coming in.
In Cubase SE, you would click the monitor button in the Track list or Inspector.
8.Press play on Computer 1.
It will now send the MIDI information on the track to the VST Instrument loaded on 
Computer 2.
Even with a slow computer you should be able to stack a whole bunch 
of extra VST Instruments this way, expanding your sound palette con-
siderably. Don't forget that VST System Link MIDI is also sample ac-
curate, and thus has much tighter timing than any hardware MIDI 
interface ever invented! 
						

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VST System Link 25 – 519
Creating a virtual effect rack
The effect sends for an audio channel in Cubase SE can either be 
routed to an FX channel track or to any activated Group or output bus. 
This allows you to use a separate computer as a “virtual effect rack”, 
by setting things up in the following way:
1.Go to Computer 2 (the machine you will use as effect rack) and add a 
new stereo audio track.
You cannot use an FX channel track in this case, since the track must have an audio in-
put.
2.Add the desired effect as an insert effect for the track.
Let’s say you add a high-quality reverb plug-in.
3.In the Inspector, select one of the VST System Link busses as input 
for the audio track.
You want to use a separate System Link bus, which will only be used for this purpose.
4.Route the channel to the desired output bus.
If you are using Computer 1 as your main mixing computer, this would be one of the 
VST System Link output busses, connected to Computer 1.
5.Activate monitoring for the track.
6.Now, go back to Computer 1 and select a track to which you want to 
add some reverb.
7.Bring up the effect sends for the track, in the Inspector or the mixer.
8.Pull down the send routing pop-up menu for one of the sends, and 
select the VST System Link bus assigned to the reverb in step 3.
9.Use the send slider to adjust the amount of effect as usual.
The signal will be sent to the track on Computer 2 and processed 
through its insert effect, without using any processor power on Com-
puter 1.
You can repeat the steps above to add more effects to the “virtual ef-
fect rack”. The number of effects available this way is only limited by 
the number of ports used in the VST System Link connection (and of 
course by the performance of Computer 2, but given that it won’t have 
to handle any recording or playback, you should be able to use quite a 
lot of effects). 
						

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25 – 520 VST System Link
Getting extra audio tracks
All computers on a VST System Link network are locked with sample 
accuracy. Therefore, if you find that the hard drive on one computer 
isn’t fast enough to run as many audio tracks as you need, you could 
record new tracks on one of the other computers instead. This would 
create a “virtual RAID system”, with several disks all operating to-
gether. All tracks will remain locked together just as tightly as if they 
were all running on the same machine. This means that you effectively 
have an unlimited track count! Need another 100 tracks? Just add an-
other computer.