If you've studied the connections on your computer closely, you may well have found that a number of them are related to audio.
You'll almost inevitably have a minijack stereo output - you'll probably have plugged a pair of headphones or speakers into this already - and there's a very good chance that you'll have an input socket or two as well (possibly labelled 'mic' and/or 'line').
Given all this, we wouldn't blame you for wondering why there's any need to bother with a separate audio interface. However, there are actually several reasons to consider investing in one, and some of them are pretty compelling.
Before we get into the 'why', though, let's take a moment to explain precisely what an audio interface is. To be honest, there isn't really that much to say here: the name gives you a pretty good idea of what you're dealing with.
Put very simply, audio interfaces enable you to get sound in and out of your computer. If you have the right hardware (specifically, a spare PCI slot) you can install one inside your Mac or PC, but most people these days choose to buy an external model.
The majority of these interfaces connect up over USB 2.0 or FireWire, and are extremely easy to install and set up. In many cases, it's just a case of plugging in a cable and you're ready to go.
Reasons to buy
The first area where a dedicated audio interface will trump your computer's built-in sound system is that of quality. Yes, you can record through that little socket on the back of your PC, but the results might not sound as pristine as you want them to.
Most of today's dedicated boxes enable you to record at better-than-CD-quality, though - if you want to get technical, we're talking 24-bit as opposed to 16-bit - and their inputs should be free of any interference or crackle.
If that isn't enough to convince you that you need an audio interface, allow us to draw your attention to their flexibility.
Many interfaces come with dedicated inputs for guitars, mics and other musical gear, enabling you to record a wide variety of instruments. What's more, an audio interface can give you the option of recording multiple tracks simultaneously - an essential feature if you happen to be in a band.
A desire to record 'real' instruments isn't the only reason to buy an audio interface, though. If you plan on using any virtual instruments, you'll find that an interface will make playing them much easier. This is because of latency - the perceptible delay between you pressing a key on your MIDI keyboard and actually hearing the sound.
If you're using your computer's built-in sound system, this delay can be quite long, but because most interfaces have well-programmed drivers - pieces of software that enable them to communicate with the computer - if you use one, virtual instruments can usually be played without any noticeable delay at all.
So, however you plan to make your music, an audio interface can almost be considered an essential purchase. It's just a case of finding a model that suits your needs and budget.
E-MU 0202 £79
Popular cross-platform USB 2.0 audio interface that will let you record guitars, mics and anything else at high quality.
A flexible and affordable USB interface that offers two inputs and four outputs. It even has a selection of built-in effects.
With a fast USB 2.0 connection and bundles of inputs and outputs, this is a fully-featured interface at a great price.
If you're looking for a sleek, high-quality partner for your Apple laptop (though not the new MacBook), this good-looking FireWire interface fits the bill. Sadly, it doesn't work with the PC though.
For more advice, check out The Computer Music Special Beginner's Guide (volume 32) which is on sale now.