"The Sound of Music" with Eric Rinker

Let’s talk about distortion. It's that knob on your amp or pedal that screams for attention. We can call it the "instant satisfaction" knob if you'd like. Some guitarists use distortion for saturation, sustain, tone, but some just because it's all they know and the salesman at the music store told them "TURN THIS KNOB ALL THE WAY UP FOR THAT GREAT DIAMONDBAG DARRELL SOUND"...
Let's get a little science out of the way, and figure out just what exactly distortion does to your guitar's signal/sound.
Distortion. It makes older folks cringe and the younger guys play endless arpeggio sweeps at music stores over and over. I’d like to hear them play them with no distortion. Distortion can be a smooth and warm overdrive to a loud wall of sonic HISSSSSS. There are many factors to getting different sounding distortions. Are you using your amp or a pedal for distortion? Is it a tube or solid state amp? Regardless of what method you use to get distortion, what you are hearing is called clipping. And to understand clipping, you need to understand what a waveform is.
It looks like it sounds:

http://upload.wikimedia.org/wikipedia/commons/8/88/Distortion_waveform.png







http://upload.wikimedia.org/wikipedia/commons/2/2a/Clipping_compared_to_limiting.svg

In the second photo is a great example of clipping/distortion in action. You'll see the blue dotted parallel lines or the “threshold”. This is the voltage limit of the signal. In the digital realm (computers, 1’s and 0’s, etc), the limit is 0db. Anything past that and it’s just nonsense hissing. This threshold is where the equipment will not let the signal go above, and anything that goes above this threshold will be truncated or “clipped”, resulting in the crests of the sound wave being square. This is what we hear as distortion, the truncating of information past a set threshold. This is extreme of course, and the clipping makes amplifiers need to use more juice, and sound very harsh with lots of high frequency harmonics.
With tube amps this clipping is done with a lot more finesse. The tubes amplify the quiet part of the signal to get them closer to the threshold, while leaving the already louder signal relatively the same. This is called compression. And a lot of people seek this guitar tone because of the even-order harmonics it makes, giving it a warmer and fatter tone. Yes, compressors can make distortion.
Now that we’ve talked about what distortion is and how clipping works, next time we’ll talk about distortion, EQ, and gain in a live setting, and the contrast you should make with the other instruments you may be accompanied by, and making space for them. Whether you’re playing death metal, the newest “core” band, or jazz, sounding good live is all about contrast.
Oh and why practicing with high gain distortion is doing you a disservice…
Some terms you should get familiar with:
Harmonics and overtones. (not “pinch” harmonics or “artificial” harmonics)
http://en.wikipedia.org/wiki/Harmonic

http://upload.wikimedia.org/wikipedia/commons/8/88/Distortion_waveform.png