Using VST Synths with QWS

QWS does not provide in-built support for software synthesisers such as VST plugins. However, by using additional programs, it is possible to take advantage of the facilities these can offer.

This article describes programs which may be used to access such soft synths. Please note though that no recommendation or endorsement of any such additional programs is made or implied, these programs are cited as examples. All trademarks are the property of their respective owners. Sorry, that's the usual disclaimer mumbo-jumbo!

Many thanks to Arthur Pirika and Andre Louis for this article.


The first tool you'll need is a virtual MIDI loopback cable. Examples are MIDI Yoke, from, or LoopMIDI, from Note that MIDI Yoke may not work with Windows 10, LoopMIDI is a good alternative.

The virtual MIDI cable will pass the MIDI data between QWS and the VST host, which neetly leads us on to...

Second, you need a program that will host the VST plugins. A free tool, called VstHost, is available from

Lastly, you'll need some VST plugins. Either Google for free VST plugins, or if you have access to some of the popular VST plugins, you can use these. So, now that we have the tools, let's get configuring.

Configuring the Virtual MIDI Cable

If you are using LoopMIDI, run it before you launch QWS. The first time you use LoopMIDI, you will need to create the virtual MIDI ports you want: simply type a name into the box and press the Add button; repeat for as many ports as you want.

If you installed MIDI Yoke, this will run as a driver and give you virtual MIDI ports all the time.

Configuring QWS

Now, open QWS and open the Ports dialog under Options by pressing ALT+O, P, and check in the list of ports that your virtual MIDI ports show up. For MIDI Yoke, these are called MIDI Yoke 1-8; for LoopMIDI, the ports will have the names you chose when setting them up in LoopMIDI.

Next, we'll need to do some configuring so that we avoid MIDI feedback loops caused by MIDI THRU. This feedback will most likely cause your machine to lock up.

So, in the Ports Options dialog, in the MIDI IN section, disable all the MIDI Yoke or LoopMIDI ports, but leave the MIDI OUT section alone. Then choose OK and QWS will update its configuration file with the new settings. Note: To speed up this process, you can press ALT+U on each port to disable it, SHIFT+TAB and then repeat.

Notice that in the Ports dialog you can also assign friendly names to your virtual ports, we recommend that you set these up so it's much easier to find your ports in the future.

Now, QWS is configured and ready to go, so it's time to move on to configuring the VST host.

Configuring VstHost

Note: different versions of VstHost may have the commands in slightly different places. If you cannot find a command as advertised, feel free to explore the menu system.

Load up VstHost, and start by opening the Wave dialog from the Devices menu (press ALT+D, W) to configure your wave devices. Ignore the input device and tab to output. If you have Asio devices installed, they will show up, else you will have to make do with MME drivers. If you have a half decent PC and CPU, you can achieve close to real-time latency, about 60 ms or so, but this is still a little too much when quantising. You will find that a little more work will be needed to get the peace sounding tight if you have this configuration. But, with Asio drivers, it is very possible you can take advantage of near 0 ms latency, so this will not be a problem. For MME drivers, set the buffer to around 300 or so; this will give you the previously mentioned responsiveness. If clicks and pops occur when playing synths, then increase this setting until they go away.

Now, configure MIDI devices that will be used by opening the MIDI dialog in the Devices menu (press ALT+D, M). On the input tab, select one of the virtual MIDI ports as input. Since we want to use multiple plugins, each controlled by a separate port, press SHIFT+F8 to enter multi-selection mode and use the cursor keys and SPACE to select and unselect ports. For example, in our configuration, we have MIDI Yoke 3-6 selected. None of the other tabs in this dialog are important at the moment, so ENTER on OK and now it's finally time to load plugins.

The process is fairly straightforward. From the File menu, choose New Plugin (press CTRL+N) to load a plugin, browse to the DLL for the synth you want to load and open it. Now you'll have a window in an MDI (multi-document interface) that shows the title of the current synth. This shows what synth changes will apply to. Now, to set up each synth and tell it what virtual MIDI port to use, go to the Plugin menu and select MIDI Devices. Under MIDI input, change the selection from all MIDI devices to one of the virtual MIDI ports. Now press OK, and repeat the procedure for each plugin you want to load. To keep track of what plugin you're working with, look at the checked menu item in the Window menu.

Please note that some of the above options and commands may be different with various versions of VstHost.

Once all plugins are configured to your satisfaction, go to the File menu, select Save Performance As, and choose a performance number to save in, for example 001. Name the performance, hit OK, and now things should be saved. Note that for whatever reason, it is not possible to save a performance in bank 0, so choose another bank when saving.

When you next load VstHost, use CTRL+L and select the performance you saved. This will load all plugins and assign them to the correct ports. Please note: while you are working with VST synths, it is necessary to keep VstHost running. Don't press ALT+F4 in VstHost, it will close and not minimize to the system tray.

That's it! You can now use multiple VST's from QWS.


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