Introduction

If soundfonts are static files that gives you unique sounds in your DAW, then VSTs are interactive applications that give the same functionality. And even more. Being programs with graphical user interfaces, they are much more flexible than soundfonts. This flexibility may explain why some people believe that VSTs are better than soundfonts. But that is not always true.

VSTs commonly have the DLL extension (or other dynamic loadable libraries or executable extension depending on your operating system). The VST specification was developed by Steinberg back in 1996 (and has been updated since then). And if they ask you in class, VST stands for Virtual Studio Technology.

Different types of VSTs

VSTs may be categorized based the types of input and output they have.

VST Instruments (VSTi)

VST instruments have the same purpose as soundfonts.  They take MIDI data as input and output corresponding audio data. In comparisson, soundfonts are “static” files containing sampled data while VSTi’s allow user interaction adjusting knobs here and there and using different setting presets. Imagine tweaking the tone or gain knobs of an electric guitar or its amplifier.

Synthesizers

Synthesizers generate sound programmatically. The sounds are not stored on the disk but are calculated as needed. Various audio synthesis techniques and physical modelling are used to emulate instrument sounds. There are also dedicated synthesizers that allow you to design your own sounds. Some examples of synthesized instrument VSTs include Spicy Guitar, Cellofan and Synth1.

Romplers

Real acoustic sounds are complex in nature. Therefore it would be a challenge to accurately synthesize them, especially for real time playing. Hence, romplers or samplers share similarities to soundfonts as they also use static files that contain the sample sound data. Due to the bundled extra data they are typically larger than synthesizer based VST instruments. The VST instruments in DSK Music are examples of romplers (that’s also where I learned the term).

Why not just use soundfonts then? Romplers allow more sound parameters to be tweaked. Advanced VSTs can also automate other rendition tweaks such as legato, chord detection, key-switching, arpeggios and many more that would otherwise require tweaking manually the MIDI arrangement. Companies would prefer to program their VSTs since this allows them to use special proprietary sample formats that protect them from being ripped off. They can also protect their products using license keys or other registration methods like how it’s done with many proprietary software.

Samplers/sample players

They are very similar to romplers. The difference is that it loads other samples/soundfonts that you may already have. Are they of any use if your DAW can already load samples directly? Yes. They may offer more control and compatibility to the samples being loaded. Examples include DSK’s SF2, Cakewalk’s sfz player, Plogue’s sforzando, Beat Zampler and Shortcircuit.

VST effects

Many stereo systems will have equalizers, or bass, treble and tone knobs. Some that allow microphone inputs will often have reverb or echo. Electric guitar amplifiers and effects would have a lot of knobs and pedals that alter the sound in many interesting ways. Equalization, reverb, echo and other effects can also be done in computer audio. Encapsulating these effects as a VST makes them modular and be used across different DAWs. VST effects take in audio data as input then output them as modified audio data (which in turn can be sent to another VST effect, a process known as chaining). Since they don’t use MIDI as input, they can also be used audio editors such as Wavosaur and Audacity. Kjaerhus Audio Classic Series contains several examples of VST effects.

Special purpose VSTs

Since VSTs are computer programs, and computer programs can be anything that brilliant programmers can imagine, there are many VSTs that do not fall in the instrument or effects categories. Examples include arpeggiators, spectrum analyzers, visualizers etc. Some VSTs will also have MIDI as an output, possibly modifying the input MIDI or detecting the notes of input audio. In the case of visualizers or analyzers the outuput is neither MIDI or audio.

Using VSTs

As with soundfonts, when I am asked by other beginners how do use VSTs, I just tell them to load them in Synthfont with a MIDI file. It handles VST instruments in a similar manner that it handles soundfonts. It also makes sense to use both VSTs and soundfonts in the same program. Digital audio work stations are expected to work with VSTs. Some VST hosts applications  will also you to play, without recording and editing around using a MIDI device as input. Bedroom producers blog has a good list of free VST hosts (I use Tocca’s VST Player, but its website is gone now). Recently, I’m also finding VSTHost to be quite convenient, being a minimal/simplistic nag-less VST Host.

Where to get VSTs

I don’t know of a de facto website where you can get VSTs and anything would suggest wouldn’t be any better than what you can find via google search. Anyone tech savvy enough to program VSTs would likely maintain their own websites. Hence, VSTs would be scattered all over the internet. In any case, here are a few suggestions to get you started:

• DSK Music. The first free VST website I knew. They have a good collection of instruments.
• MDA. An assortment of VST instruments and effects. They are now open source, hence the special mention.
• 4Front. Various pianos and a bass VSTi’s.
• Acoustica. Where you may find the Kjaerhus Audio Classic Series which contain effects such as equalizer, flanger, chorus, reverb and more.
• KVR Audio. A great community where you can find a lot of software meant for sound developers/DAW-ists/digital musicians. It lists both free and paid VSTs.
• VST 4 FREE makes an effort to list Free VSTs and seems quite updated.

This is obviously not a definitive or exhaustive list. There’s far too many of them, that I don’t even know if I’m suggesting the best ones. Just be happy that you have the freedom of choice! (Or sad that there’s too much to choose from. Reviews and forums can be helpful.) :)

Other formats

Just like any computer program VSTs are not directly useable across operating systems. But since VSTs seldom (if not) use advanced OS specific APIs WINE can do a good job in bridging this gap. Needless to say, Apple and Linux have their own native alternatives to VSTs. These are Audio Units (AU) and the Linux Audio Developers Simple Plugin API (LADSPA) respecitvely. DAWs can also have some sort of VST-like modules that are not usable to other DAWs.