Personally, I prefer to have an external audio interface rather than the internal PCI sound cards that are fitted inside your computer (like the classic Sound Blaster sound card for instance) although internal PCI sound cards are great workhorses for gamers and people watching films on their PC.
The right external audio interface can offer various advantages:
- You won’t need get to the back of your computer every time you want to plug in a microphone or your electric guitar.
- Many audio interfaces have better quality pre-amps for each of the audio inputs. This means that when you plug an instrument or microphone into you sound card, you’ll get a better signal to noise ratio (basically less noisy inputs) and often a better tonal quality to your recordings. For the recording musician a decent pair of pre-amps are a must, but you will find that there is much debate about the best ones. I personally really like the ones in my PreSonus FireBox (this particular box plugs in via a Firewire connector and not USB). I certainly wouldn’t go back to the plain inputs found in some devices.
- You’ll often have a dedicated volume control with which to control the output to your speakers, and often gain controls to vary the amount of signal flowing from your instrument into your computer. This is really handy for ensuring that you get optimal signal volume once it gets to your recording software.
- Fantom power! Some microphones, especially condenser microphones require power to operate. Some mics get this power from a battery fitted inside the mic, but others get their power from the audio interface. This is called fantom power, and there is usually a switch to turn it on. This is usually a feature of interfaces with three pin XLR (also known as balanced) microphone connections. Not essential for the beginner, but experienced and serious users will want to have this type of connectors!
- Bus power. If you get the right audio interface, then you won’t need one of those horrible ‘wall wart’ power supplies, as many units can derive their power from the USB connection (often called the USB Bus). This is great news if you’re wanting to take your laptop and interface out and about for recording on location away from your studio. I also find that external power supplies introduce unwanted noise and irritating ‘ground loop’ hums, so if you can avoid them its often beneficial.