Here's a number of examples of how you could set up your home or project studio with a computer, a soundcard, keyboard and guitar.

This is probably what everyone really wants to see - how to set it all up. The problem from my point of view is that it really does depend on what you've got and what you are trying to do. I get many emails from people saying they have this that and three of these and how on earth do they plug it all together? My reply to which is often "I dunno, how do you want to plug it together?". For instance, if you have a hardware mixer and hardware effects then you plug it together in such a fashion as to make it do what you want it to do - it can be the same with computer music gear. That said there are some basic rules you can follow and what you need to do is try to apply what I'm showing you to your own gear. Most importantly, if you don't know why you need something then you don't need it. Mixers are a classic example. The number of people I've heard from who bought mixers because someone said they needed one but have no idea what it is or how to use it. You only need a mixer if you know need a mixer, if you're not sure then the likelihood is that you do not need one. Another good tip with mixers is to count up how many boxes you have that make a noise. If it's just your PC then you don't need a mixer. If you've got racks of hardware synths and a Trinity keyboard then you are going to want to "mix" all those sounds together so that they come out of the same pair of speakers - then you need a mixer.

So, mixers, if you have one knocking about, can be useful, but if you don't then you probably don't need one. Cool? 

Example 1 - Basic Setup

To make music on your computer you need a soundcard. Most computers come with a rubbish one built in that gives you a mic input, a line input and line or speaker outputs. Now don't go thinking just because you've got built in 7.1 surround with some kind of high definition SoundBlaster chipset that it's going to be any good for making music - it'll do for starters but you may discover that it has many frustrating limitations and if you make the jump to a soundcard that's designed for music production your computer music making experience will vastly improve. Anyway, check out the hardware section for more on that, let's get on with dealing with what we find.

One PC, built in soundcard, one MIDI keyboard (optional), a guitar (optional) and a pair of speakers (these could potentially be headphones) - groovy.

Okay, let's have a go at explaining what's going on by numbers.

1. Plug a guitar cable into your guitar. The guitar is being used here as an example of an instrument. It could be any other instrument or just a microphone.
2. The standard soundcard has mini-jack inputs so you need to use an adapter to take your guitar cable jack (1/4 inch) down to a mini-jack (3.5mm).
3. Plug the adapted cable into the microphone socket on the soundcard.
4. MIDI Keyboards often now come with a USB socket, if yours does go to number 6. If not then take a MIDI cable and plug it into the MIDI OUT on the keyboard.
5. Using a MIDI/Joystick adapter plug the other end of the MIDI cable into the joystick port. Remember that you only need this if your MIDI keyboard does not have a USB port.
6. A MIDI keyboard with a USB socket is providing it's own MIDI interface to the computer. Just plug the USB cable from the keyboard into the USB port on the computer, install the driver, and the keyboard's connected to the computer.
7. Line Output on the soundcard is also a mini-jack, so you'll need a cable with stereo mini-jack on one end and whatever your speakers need on the other.
8. The Line Output goes to your powered speakers, one left, one right. If you have passive speakers then plug the Line Output into the amp that's powering the speakers.

Your recording software will be able to record the guitar, and the keyboard will be able to play software synths. All the sound, from the guitar and the soft synths will come out of the Line Output into your speakers.

See, that was easy! Audio cabling is very very simple and you can adapt any analog audio connector to any other - small jack to big jack, phono to XLR, bare speaker wire into jacks - whatever you like. All decent electrical or hi-fi stores should have a range.

Example 2 - Using that old mixer

As I've already said you don't need a mixer unless you know you need one, however, it's one of the most common questions I get asked so here's an example of how to use a small mixer, this could even be an old 4-track recorder, with your computer. What the mixer does supply is a decent input stage for mics and instruments rather than using the little mic input on an inbuilt soundcard.

One PC, better recording soundcard called the Audiophile with high quality inputs, one MIDI synth keyboard with it's own sounds, a guitar, a mic and a pair of speakers. Let's see if you can follow this one.

1. Plug a guitar cable into your guitar.
2. Plug a suitable cable into your microphone.
3. Plug the mic and guitar into separate channels on the mixer. You could use a separate preamp for the guitar and the microphone if you like.
4. The keyboard has both a MIDI OUT and IN, this is so we can send MIDI OUT to the computer for recording, and then receives the MIDI back IN from the sequencer so the synth plays the sounds (eg. drums and instrument backing). This assumes your keyboard has its own sounds that you want to use, if not then you just need the MIDI OUT.
5. The Audiophile's MIDI interface provides the MIDI IN and OUT sockets. Remember that the OUT from the keyboard goes to the IN on the interface and vice versa. If the keyboard has a USB port then you could use that instead of the MIDI interface.
6. We want to be able to hear the synth, so we plug the audio output into the mixer.
7. This is the bit people usually have trouble with. We want to be able to record the mic and guitar onto the computer. If we used the mixers master outputs then while we are recording the guitar we would record the backing from the synth at the same time onto the same track. We don't want to do this, we want to record everything onto different tracks, and we don't want to record the synth until we're completely sure of the MIDI arrangement in the software (you still with me?). So, we need to SEND the guitar and the mic to the soundcard on it's own. How do we do this? We use SENDS. All mixers have an auxiliary send or two, sometimes called "FX Sends" as that's what they are normally used for - sending the signal from channels out to effects. However, this time we are going to use them like an output, and send the guitar/mic channel out of the send and to the soundcard. So, turn up the send knob on the guitar and mic channels, and make sure the sends on the other channels are at zero. Now we'll be able to hear the synth, but it won't get recorded with the guitar. Super, got that? Good.
8. The output from the aux send, ideally two for stereo, is plugged into the Line Input on the Audiophile (soundcard).
9. Now, we want to be able to hear the recorded guitar at the same time as the output of the hardware synth, so the Line Output of the Audiophile needs to be plugged into the mixer.
10. Make sure the aux send on the channels for the soundcards output are at zero or you might get feedback through the computer.
11. The monitor output of the mixer carries the recorded tracks from the computer and the output of the synth and should be plugged into your speakers.
12. All the sound comes out of your powered speakers, or amp and speaker arrangement.

A good note to make at this point is that although you're using a mixer, you're not actually using it to mix anything. All you've got is a stereo output from the synth, possibly carrying multiple tracks of different instruments and the stereo output from the computer, which could carry a couple of guitars, vocals and harmony. So, all the mixing needs to be done on the computer, in Cubase or whatever
you're using. Also if your mixer has direct outputs or tape outputs or busses then you don't need to use the auxiliaries, just treat the computer like a hardware recorder.

Example 3 - Recording a band using a proper recording interface

This is a great example drawn by someone else for a change (hooray!). It's from the Presonus website showing how their excellent Firepod could be connected up. The term "Soundcard" is obviously inaccurate in this case as the Firepod is a Firewire interface, however, I use the word "soundcard" to cover all audio interfaces to the PC whether they are PCI cards, PCMCIA, Firewire or USB - just so you don't get confused!

This one is probably better explained without the numbers as you get the general idea just by looking at it.

Summary

As you can see you don't need a mixer. The Firepod is providing all the inputs and preamps you need, for mics for guitars, for whatever you want to throw at it. All the mixing is done on the computer in your audio software resulting in a stereo monitor output going to your speakers. If you are unhappy about the idea of mixing with a mouse then you'll need to enter the world of the MIDI control surface where you have a slab of plastic with a bunch of faders and knobs that you use to control the software mixer on screen - full tactile control often with motorised faders and all sorts of flashing lights. You'll find more on that in the MIDI section of the website. 

If you still can't fathom it out then give me a shout!