One of the first pieces of equipment you'll need to record music on your computer is an audio/digital (A/D) interface. The A/D Recording Interface converts audio (analog) signals from your microphone or other sound source into digital data that your computer can record and process. A first time recordist may find the array of available interfaces bewildering, so let's cut through the confusion. Just ask yourself a few simple questions and you'll quickly whittle down the options.

1) What kind of computer to you use: Mac or PC? Eliminate first those interfaces which cannot connect to your computer or are not supported by your software.

2) How does the Interface connect to your computer? Three types of connections are common: USB, Firewire, or an expansion card which goes inside your computer and plugs into the motherboard. What connections do you have available on your computer now? Are you willing to install a Firewire card? While Firewire is faster, USB 2.0 is more common and will also work very well. (On the other hand, USB 1.1 is much more limited.) And if you're considering an expansion card, make sure your computer has an open slot of the correct type.

3) How many inputs will you be recording at once? I suggest you list them out. Also pay attention to what type of inputs you will need. For example, most microphones will use XLR inputs, many instruments like keyboards and guitars use ¼" inputs, and don't forget MIDI if you'll be using it.

4) Will you be mixing multiple inputs, or will you consider expanding? For example, will you be recording a full band? If so, it's worthwhile to at least consider a control surface or a mixer with built in interface.

5) What signal quality do you want or need? Even without understanding all the audio specifications, you can sort through a lot of them just by knowing that Audio CDs use 16-bit resolution and a sampling rate of 44.1 KHz. Higher resolution and sampling rates produce cleaner sound; that's good if you need it! On the other hand, higher resolution and sampling rates also produce way more data - which can quickly overwhelm your computer processor and speech to text software up huge amounts of disk space. Your job is to strike a balance which meets your own needs.

6) Does the interface you're considering provide outputs for your monitor speakers and/or headphones? This isn't essential. You can plug both into your computer. Right? Well, depending out your equipment, you may find yourself playing a note on your guitar and then hearing that note coming through your speakers or headphones a fraction of a second later. (That annoying fraction of a second of delay between signal input and output is referred to as latency.) So, if your interface offers a headphone output with zero latency, that can be a huge help for overdubbing tracks!

7) What other features are you looking for? Think about it. Do you need microphone preamps? What about reverb or other effects? Again, these are not essential features. You may have separate preamps or effect processors, or you may use a plug-in to provide effects within your computer. On the other hand, an onboard preamp may be just the ticket to simplify your gear and improve your signal.