So, when talking about “VST effects” what do we actually mean? These are audio effects, designed to mimic the hardware effects processors you’d see in the studio. That would mean effects like reverb where you can give the audio recording a sense of space, or chorus where it adds modulation and wobble to a signal, or delay where it provides an echo of whatever is running through it.

You could also see them as individual guitar stomp-boxes offering all sorts of sound changing effects. Dynamics processing is crucial when mixing audio and so we have compressors, limiters and EQs to enhance and control the sound.

In a hardware environment, effects were commonly used via “Inserts” on a mixing desk which diverted the audio signal through the effect box and back again to the mixer. Software DAWs would copy this concept and give you a virtual mixing desk with insert buttons that you could click on to insert a VST effect.

This was seen as “plugging in” an effect onto an audio channel and so the term “plugin” was coined to describe these software effects. This would also include those used by DAWs that have their own non-VST format of effects. So, a “plugin” and a “VST” are two ways of describing the same thing and they are often used together as in “VST plugin” or you may find “VST effect” or “plugin effect” used as well.

Hardware has physical limitations to deal with in terms of the number of mixer channels you have or external effects boxes that physically exist in your studio. The only limitation you have in the software world is the power of your CPU. Each loaded plugin is constantly working on the audio stream and so every time you add one it uses up a small amount of your CPU power. Eventually, after adding multiple VST plugins you will run out of CPU power and your system will no longer be able to produce sound without glitching and audio dropouts.

So, no system is limitless. But there are things you can do to minimize this limitation. Using “Sends” where you load a single plugin and route lots of channels to it is one good idea. It makes sense to do this for effects like reverb where you’ll want your whole mix to sound like it has come from the same environment rather than insert a reverb on every track. You can bounce a mix of a track with the effects so that they are permanently applied to the audio and then unload the plugins to recover some of that processing power.

Some DAWs can “freeze” tracks where you can temporarily apply the loaded effects to a track and automatically unload the plugins. This is preferred to the bounce method as you can “unfreeze” the track and edit the effects later if you wish.

With a modern computer, there’s no reason why you can’t have a 32-track or 64-track project with every channel running individual compression and EQ plugins and multiple creative plugins like phasers, delay, distortion, filters. Add a large and complex reverb on a send channel and a multi-band compressor on the master output and you have everything you’d find in a hardware studio right on your computer.

There’s another aspect to the VST plug-in that we haven’t covered yet and that’s instruments. VST Instruments or “VSTi’s” for short arrived with version 2 of the VST format which added a MIDI input and the possibility of sound generation rather than just processing.

This gave birth to the software synthesizer that you could plug into your DAW. Up until this point, MIDI sequencing had to be directed to external hardware synthesizers whereas now software models of synthesizers could be run, played and sequenced on the same computer, in the same DAW as your audio tracks.

From the very humble beginnings of simple software synths, the power of computer processing has enabled the development of a whole range of software sound generators and instruments. There are plenty that model the circuitry of hardware synthesizers but also plenty more that take sound design and synthesis into places that hardware can’t go.

With the large amount of storage space and memory available on a computer, it became the ideal platform for sample-based instruments. A whole industry has risen up around the sampling of live instruments and producing the equivalent of virtual orchestras and ensembles. The multiple levels of high-quality sampling available in modern orchestral sound libraries can run into several Terabytes.

VST is not the only plugin format. VST is predominantly a Windows format as since OSX the MacOS uses a format called AU (Audio Unit). You’ll also find this format on iOS devices such as the iPad. Avid’s Pro Tools DAW has its own plug-in format called AAX.

In Propellerhead’s Reason DAW they have the Rack Extension format although they also support VST/AU plug-ins and the instrument rack can be used as a VST plugin in other DAWs. All the formats achieve the same thing of being virtual effects processors and virtual instruments running within the DAW.

What the VST protocol has enabled us to do is take the massive amount of external hardware processes, synthesizers and instruments usually associated with studio recording and place them inside our computers.

Where once you needed a huge room filled with gear now all you need is a laptop and a pair of headphones. And much of it you can do for a fraction of the cost. It’s enabled us all to become Sound Engineers and Producers and has brought the delights of music production with authentic-sounding instruments within reach of everyone.

That’s not the whole story because in these enlightened times we’ve come to realize that software representations of hardware are not always as inspirational or engaging as the hardware itself. We’ve found that there’s something very human in the turning of physical knobs and the playing of instruments that software struggles to replicate.

So, whereas 10 years ago it seemed that VST plugins would be all we’d ever need, we’ve found usefulness and creativity in both software and hardware and these days we’ve seen a bit of a hardware renaissance. Hardware synths are a lot of fun, but software ones can do extraordinary things that sometimes go beyond physical restraints.

I can record live guitar for a more nuanced performance than using a virtual one but recording an amplifier with a microphone at home can be troublesome and so virtual amps are a great solution. And who can afford to hire an orchestra?

So, these days in music production neither software nor hardware is king. Software can keep things affordable while a modest amount of hardware can stretch your creativity and help us feel authentic. You use whatever fits your situation and enables your creativity.